<PAGE>


                                                                Exhibit 10.19(a)

                                LIMITED EXCLUSIVE
                     PATENT AND COPYRIGHT LICENSE AGREEMENT

                                       FOR

                      PEREGRINE(TM) DOSE CALCULATION SYSTEM
                        FOR RADIATION TREATMENT PLANNING

                                     BETWEEN

                   THE REGENTS OF THE UNIVERSITY OF CALIFORNIA

                                       AND

                                NOMOS CORPORATION

                            LLNL CASE NO. TL-1613-99

                     LAWRENCE LIVERMORE NATIONAL LABORATORY
                            UNIVERSITY OF CALIFORNIA
                    P.O. BOX 808, L-795, LIVERMORE, CA 94551
                  INDUSTRIAL PARTNERSHIPS AND COMMERCIALIZATION

                                    JULY 1999



<PAGE>


                                                                Exhibit 10.19(a)

                                TABLE OF CONTENTS
<TABLE>

<S>      <C>                                                                                                     <C>

1.    BACKGROUND..............................................................................................   1


2.    DEFINITIONS.............................................................................................   3


3.    LICENSE GRANT...........................................................................................   7


4.    SUBLICENSING RIGHTS AND OBLIGATIONS.....................................................................   8


5.    FEES, ROYALTIES AND PAYMENTS............................................................................   9


6.    PERFORMANCE OBLIGATIONS................................................................................   10


7.    PROGRESS AND ROYALTY REPORTS...........................................................................   11


8.    BOOKS AND RECORDS......................................................................................   16


9.    TERM...................................................................................................   17


10.   TERMINATION AND DISPOSITION OF LICENSED PRODUCTS.......................................................   17


11.   PATENT PROSECUTION AND MAINTENANCE.....................................................................   19


12.   PATENT AND COPYRIGHT INFRINGEMENT......................................................................   20


13.   USE OF NAMES AND TRADEMARKS............................................................................   22


14.   LIMITED WARRANTY.......................................................................................   22


15.   INDEMNIFICATION........................................................................................   24


16.   INSURANCE..............................................................................................   24


17.   WAIVER.................................................................................................   26


18.   ASSIGNABILITY..........................................................................................   27


19.   LATE PAYMENTS..........................................................................................   27


20.   NOTICES................................................................................................   27


21.   DISPUTES AND GOVERNING LAWS............................................................................   28


22.   PATENT MARKING.........................................................................................   28


23.   COPYRIGHT MARKING......................................................................................   29


24.   GOVERNMENT APPROVAL OR REGISTRATION....................................................................   30


25.   EXPORT CONTROL LAWS....................................................................................   30


26.   FORCE MAJEURE..........................................................................................   31


27.   UNITED STATES PREFERENCE................................................................................  31


</TABLE>





<PAGE>



<TABLE>


<S>      <C>                                                                                                    <C>
28.   PROPRIETARY INFORMATION...............................................................................    31


29.   MISCELLANEOUS.........................................................................................    32


EXHIBIT A - LICENSED PATENTS AND LICENSED COPYRIGHTS........................................................    34


EXHIBIT B - RIGHTS GRANTED AND PERFORMANCE OBLIGATIONS......................................................    41


EXHIBIT C - FEES AND ROYALTIES..............................................................................    46


EXHIBIT D - MUTUAL NONDISCLOSURE AGREEMENT..................................................................    50

</TABLE>























<PAGE>




            LIMITED EXCLUSIVE PATENT AND COPYRIGHT LICENSE AGREEMENT
                    FOR PEREGRINE(TM) DOSE CALCULATION SYSTEM
                        FOR RADIATION TREATMENT PLANNING

This Agreement is effective on the Effective Date by and between The Regents of
the University of California ("THE REGENTS"), under its U.S. Department of
Energy Contract No. W-7405-ENG-48 to manage and operate Lawrence Livermore
National Laboratory ("LLNL"), and NOMOS Corporation, a Delaware corporation
having its principal place of business at 2591 Wexford-Bayne Road, Sewickley, PA
15143. THE REGENTS is a corporation organized and existing under the laws of the
State of California, with its principal office at 1111 Franklin Street, 12th
Floor, Oakland, CA 94607-5200. THE REGENTS and NOMOS Corporation are referred to
jointly as "Parties."

1.       BACKGROUND
1.1               Certain inventions characterized as the PEREGRINE(TM) Dose
                  Calculation System ("Inventions") and certain copyrightable
                  works characterized as the computer program PEREGRINE(TM)
                  version 1.1 ("Software"), described in LLNL patents, patent
                  applications and copyrights listed in Exhibit A (LICENSED
                  PATENTS AND LICENSED COPYRIGHTS), which may be useful for
                  various radiation therapy applications, were made at LLNL and
                  are covered by THE REGENTS' Patent Rights and THE REGENTS'
                  Copyright Rights as defined in Article 2 (DEFINITIONS).

1.2               LLNL published a Commerce Business Daily announcement in which
                  it sought one or more industrial partners to commercialize the
                  PEREGRINE(TM) Dose Calculation System as a means of achieving
                  LLNL's objective of ubiquitous, rapid distribution of
                  PEREGRINE(TM) to radiation therapy clinics. NOMOS Corporation
                  responded to LLNL's





                                       1
<PAGE>



                  announcement and shares LLNL's objective in commercializing
                  the PEREGRINE(TM) Dose Calculation System. NOMOS Corporation
                  Radiation Treatment Planning

1.3               NOMOS Corporation entered into a Mutual Nondisclosure
                  Agreement provided in Exhibit D (MUTUAL NONDISCLOSURE
                  AGREEMENT), which is incorporated herein, that allowed it to
                  evaluate its interest in taking a license to the Inventions
                  and Software.

1.4               NOMOS Corporation is interested in acquiring certain rights to
                  the Inventions and Software for the development, manufacture,
                  and sale of products and services based on the Inventions and
                  Software. In addition to selling directly to its customers,
                  NOMOS Corporation is willing to sell such products on an OEM
                  basis or to sublicense Inventions and Software to other
                  companies, including NOMOS Corporation's competitors, to
                  facilitate ubiquitous, rapid distribution of the PEREGRINE(TM)
                  Dose Calculation System.

1.5               THE REGENTS is willing to grant such rights so that the
                  Inventions and Software may be developed and used to the
                  fullest extent for the benefit of the Unites States' economy
                  and the general public.

1.6               NOMOS Corporation recognizes that royalties due under this
                  Agreement will be paid on licensed patent applications, issued
                  patents, and copyrights.

1.7.              The Parties have entered into a Work for Others agreement to
                  facilitate transfer of the PEREGRINE(TM) Dose Calculation
                  System to NOMOS





                                       2
<PAGE>



                  Corporation for commercial development and to further develop
                  the Inventions and Software.

1.8               NOMOS Corporation is a "small entity" as defined in 37
                  CFRss.1.9.

1.9               NOMOS Corporation is a "small business firm" as defined at
                  section 2 of Pub. L. 85-536 (15 U.S.C.ss.632).

THEREFORE, the Parties agree as follows:

2.       DEFINITIONS

2.1               "Effective Date" means the date of execution by the last
                  signing Party.

2.2               "Field of Use" is the application or use defined in Exhibit B
                  (RIGHTS GRANTED AND PERFORMANCE OBLIGATIONS).

2.3               "Government" means the United States Government.

2.4               "Lease Price" means gross income from a contract by which
                  LICENSEE or its sublicensees conveys Licensed Products for a
                  specified term at a specified fee.

2.5               "Licensed Methods" are any methods, procedures, processes, or
                  other subject matter whose use or practice would constitute an
                  infringement of THE REGENTS' Patent Rights but for the license
                  granted to LICENSEE under this Agreement.

2.6               "Licensed Patents" are:






                                       3
<PAGE>



                  2.6.1    U.S. patents and U.S. patent applications specified
                           in Exhibit A (LICENSED PATENTS AND LICENSED
                           COPYRIGHTS), and U.S. patents resulting from these
                           applications and continuations of these applications,
                           including divisionals resulting from these
                           applications, but not including continuation-in-part
                           applications resulting from these applications;

                  2.6.2    reissues of 2.6.1;

                  2.6.3    foreign patent applications filed under Article 11
                           (PATENT PROSECUTION AND MAINTENANCE) and patents
                           resulting from these applications; and,

                  2.6.4    Licensable WFO Subject Inventions.

2.7               "Licensed Products" are products that 1) incorporate or are
                  produced by the practice of subject matter claimed in Licensed
                  Patents, and whose manufacture, use, sale, import, or offer
                  for sale would constitute an infringement of THE REGENTS'
                  Patent Rights, or 2) duplicate, display, perform, or are
                  Derivative Works of the subject matter of Licensed Copyrights
                  and whose duplication, distribution, display, or performance
                  would constitute an infringement of Licensed Copyrights, but
                  for the license granted to LICENSEE under this Agreement.

2.8               "LICENSEE" means NOMOS Corporation.

2.9               "Net Sales," as used in this Agreement to compute royalties,
                  means the aggregate Sale Price, Lease Price, and Service Price
                  of Licensed Products and Licensed Methods by LICENSEE and any
                  sublicensees in transactions throughout the world with
                  independent third parties for cash, or other




                                       4
<PAGE>



                  consideration as mutually agreed by the Parties, using
                  generally accepted accounting principles.

                  No deductions will be made from Net Sales for commissions paid
                  to individuals whether they are with independent sales
                  agencies or regularly employed by LICENSEE and on its payroll,
                  or for cost of collections.

2.10              "Sale Price" means the gross invoice selling price after
                  deducting:

                  2.10.1   Discounts allowed in amounts customary in the trade;

                  2.10.2   Sales, tariff duties or use taxes directly imposed
                           and with reference to particular sales;

                  2.10.3   Allowances actually paid and limited to rejections,
                           returns, and prompt payment and volume discounts
                           granted to customers of Licensed Products, whether in
                           cash or Licensed Products in lieu of cash;

                  2.10.4   Freight, transport packing, insurance charges
                           associated with transportation; and

                  2.10.5   Taxes, tariff, or import/export duties based on sales
                           when included in gross sales, but not value-added
                           taxes or taxes assessed on income derived from such
                           sales.

                  The Sale Price of Licensed Products and Licensed Methods that
                  are disposed of other than by sale or lease is LICENSEE'S
                  gross invoice selling price for products of similar kind and
                  quality, sold in similar quantities provided that the Sale
                  Price shall not be less than the minimum value




                                       5
<PAGE>



                  established in section C.2 of Exhibit C (FEES AND ROYALTIES).
                  If LICENSEE is not currently offering comparable products for
                  sale, then the Sale Price is the average gross invoice selling
                  price at which products of similar kind and quality, sold in
                  similar quantities, are currently offered for sale by other
                  manufacturers. If comparable products are not currently sold
                  or offered for sale by others, then the Sale Price will be
                  LICENSEE'S cost of manufacture, determined by LICENSEE'S
                  customary accounting procedures, plus LICENSEE'S standard
                  markup.

2.11              "Sales of Licensed Products" means sale or lease of Licensed
                  Products or performance of services using Licensed Products,
                  Licensed Methods or Licensed Copyrights.

2.12              "Service Price" means gross income from services performed by
                  LICENSEE or its sublicensees using Licensed Products, Licensed
                  Methods, or Licensed Copyrights, including gross income for
                  support, maintenance, and repair services.

2.13              "THE REGENTS' Patent Rights" are THE REGENTS' rights in
                  Licensed Patents under applicable patent laws.

2.14              "THE REGENTS' Copyright Rights" means THE REGENTS' rights in
                  Licensed Copyrights under applicable copyright laws.

2.15             "Licensed Copyrights" means the copyrighted works listed in
                  Exhibit A (LICENSED PATENTS AND LICENSED COPYRIGHTS) and
                  Licensable WFO Computer Software.

2.16              "Derivative Work" means a work that is based on one or more
                  pre-existing works and that, if reproduced, distributed to the
                  public, or displayed





                                       6
<PAGE>


                  publicly or performed publicly without permission of the owner
                  of the pre-existing work, would constitute copyright
                  infringement.

2.17              "Licensable WFO Subject Inventions" means Contractor's Subject
                  Inventions arising from the WFO to which rights have been
                  waived to THE REGENTS by DOE for licensing in accordance with
                  THE REGENTS' Contract No. W-7405-ENG-48 with DOE.

2.18              "WFO" means Work for Others Agreement No. L-8788 by and
                  between the Parties.

2.19              Licensable WFO Computer Software" means Contractor's Computer
                  Software arising from the WFO in which the Contractor has been
                  given permission to assert copyright in accordance with its
                  prime contract with DOE.

2.20              "Use Sublicense" means any agreement by LICENSEE or a
                  sublicensee which grants to end users, only the right to use,
                  on a single computer or compute server, object code versions
                  of Licensed Products.

3.       LICENSE GRANT

3.1               The license rights granted to LICENSEE by THE REGENTS are set
                  forth in Exhibit B (RIGHTS GRANTED AND PERFORMANCE
                  OBLIGATIONS).

3.2               The Government retains a paid-up, royalty-free,
                  nontransferable, worldwide, irrevocable license to practice
                  Licensed Patents by or on behalf of the Government. The
                  Government has certain other rights under 35
                  U.S.C.ss.ss.200-212 and applicable regulations.




                                       7
<PAGE>



3.3               The Government retains for itself and others acting on its
                  behalf a paid-up, royalty-free, worldwide, irrevocable license
                  in Licensed Copyrights to reproduce, prepare Derivative Works,
                  and perform publicly and display publicly. Beginning ten (10)
                  years after January 14, 1999, subject to possible five-year
                  renewals, the Government is granted for itself and others
                  acting on its behalf a paid-up, nonexclusive, irrevocable
                  worldwide license in Licensed Copyrights to reproduce,
                  prepares, distribute copies to the public, perform publicly
                  and display publicly, and to permit others to do so.

3.4               THE REGENTS reserves all rights not otherwise granted in this
                  Agreement and the right to use THE REGENTS' Patent Rights and
                  THE REGENTS' Copyright Rights for educational and research
                  purposes.

4.       SUBLICENSING RIGHTS AND OBLIGATIONS

4.1               The sublicensing rights granted to LICENSEE by THE REGENTS are
                  set forth in Exhibit B (RIGHTS GRANTED AND PERFORMANCE
                  OBLIGATIONS), Paragraph B.2.

4.2               LICENSEE will provide THE REGENTS with an executed copy of
                  each sublicense within thirty (30) days of execution of the
                  agreement.

4.3.              LICENSEE must include in any sublicense all the rights and
                  obligations due THE REGENTS and the Government set forth in
                  this Agreement.

4.4               LICENSEE will promptly forward to THE REGENTS any reports and
                  statements it receives from sublicensees under Article 4.3.



                                       8
<PAGE>


4.5               LICENSEE must include in all sublicenses the notice that upon
                  termination of this Agreement for any reason, THE REGENTS will
                  automatically succeed to all rights of LICENSEE arising from
                  sublicenses granted under this Agreement.

5.       FEES, ROYALTIES AND PAYMENTS

5.1               As partial consideration for rights granted to LICENSEE,
                  LICENSEE will pay to THE REGENTS a license issue fee and
                  maintenance fees as set forth in Exhibit C (FEES AND
                  ROYALTIES).

5.2               As further consideration for rights granted to LICENSEE,
                  LICENSEE will pay to THE REGENTS a minimum annual royalty and
                  an earned royalty based on Net Sales as set forth in Exhibit C
                  (FEES AND ROYALTIES).

5.3               LICENSEE will pay royalties to THE REGENTS according to the
                  schedule specified in Article 7 (PROGRESS AND ROYALTY
                  REPORTS).

5.4               LICENSEE will pay all fees and royalties in U.S. dollars
                  collectible at par in San Francisco, California. When Licensed
                  Products are sold for currencies other than U.S. dollars,
                  earned royalties will first be determined in the foreign
                  currency of the country in which the Licensed Products were
                  sold and then converted into equivalent U.S. dollars. The
                  exchange rate is that rate quoted in the Wall Street Journal
                  on the last business day of the reporting period and is quoted
                  as local currency per U.S. dollar. LICENSEE will be
                  responsible for all bank transfer charges.

5.5               Notwithstanding the provisions of Article 26 (FORCE MAJEURE),
                  if at any time legal restrictions would prevent LICENSEE from
                  making payment of part or all of any royalties in any country
                  outside the U.S.




                                       9
<PAGE>



                  from LICENSEE'S source of funds outside the U.S., LICENSEE
                  will convert the amount owed to THE REGENTS into U.S. funds
                  and pay THE REGENTS directly from LICENSEE'S U.S. source of
                  funds.

5.6               No royalties are due on Net Sales to the Government. LICENSEE
                  will reduce the amount charged for such sales by an amount
                  equal to the royalty otherwise due THE REGENTS.

6.       PERFORMANCE OBLIGATIONS

6.1               LICENSEE, upon execution of this Agreement, will diligently
                  proceed with development, regulatory approvals, manufacture,
                  and sale of Licensed Products and use of Licensed Methods, and
                  earnestly and diligently endeavor to market the same as
                  specified in Exhibit B (RIGHTS GRANTED AND PERFORMANCE
                  OBLIGATIONS).

6.2               During the term of this Agreement, LICENSEE will demonstrate a
                  continuing effort to commercialize and sell Licensed Products
                  and use Licensed Methods to meet market demand.

6.3               If LICENSEE does not meet the performance obligations
                  specified in Exhibit B (RIGHTS GRANTED AND PERFORMANCE
                  OBLIGATIONS), THE REGENTS may at its sole option: (a) convert
                  the limited exclusive license for Licensed Patents and
                  Licensed Copyrights to a nonexclusive license; (b) negotiate
                  with LICENSEE a new schedule and conditions for continuation
                  of a limited exclusive license; or (c) terminate this
                  Agreement.

6.4               THE REGENTS will notify LICENSEE if THE REGENTS is approached
                  by a third party seeking a license to make, use, or sell
                  Licensed Products in LICENSEE'S Field of Use. LICENSEE will
                  negotiate in good faith with that third party to grant a
                  sublicense for any Licensed Patents or Licensed





                                       10
<PAGE>



                  Copyrights in the market for which LICENSEE and existing
                  sublicensees are not meeting commercial demand. The
                  determination to grant a sublicense may be based on LICENSEE'S
                  business interests. LICENSEE will provide THE REGENTS with
                  justification for denying any such sublicense.

6.5               During the term of this Agreement, LICENSEE will conduct
                  normal, continuous business operations. If LICENSEE seeks
                  protection under any United States bankruptcy proceedings
                  during the term of this Agreement, LICENSEE will notify THE
                  REGENTS in writing no later than seventy-two (72) hours after
                  the bankruptcy filing. THE REGENTS has the option to terminate
                  this Agreement upon a bankruptcy filing by the LICENSEE.

7.       PROGRESS AND ROYALTY REPORTS

7.1               SEMI-ANNUAL PROGRESS REPORT: LICENSEE will submit to THE
                  REGENTS semiannual progress reports according to the following
                  schedule:

                  DUE DATE                                FOR PREVIOUS PERIOD
                  --------                                -------------------

                  February 28                             July I - December 31
                  August 31                               January 1 - June 30


                  The progress report must cover LICENSEE'S activities in
                  meeting the performance obligations set forth in Article 6
                  (PERFORMANCE OBLIGATIONS) and Exhibit B (RIGHTS GRANTED AND
                  PERFORMANCE OBLIGATIONS), and must include at a minimum the
                  following information:

                  Name of LICENSEE





                                       11
<PAGE>

                  License Number

                  Date of Report

                  Reporting period

                  Summary of work completed

                  Summary of work in progress

                  Current schedule of anticipated events or milestones

                  Description of Licensed Products or Licensed Methods under
                  development

                  Licensed Patents and Licensed Copyrights practiced or
                  incorporated into each Licensed Product and Licensed Method
                  under development Anticipated market introduction date of
                  Licensed Products /Methods

                  Commercial name of Licensed Products /Methods

                  A summary of resources (dollar value) spent in the reporting
                  period on commercialization efforts

                  Name and summary of activities of sublicensees, if any

                  Changes in corporate ownership (see Article 18, ASSIGNABILITY)

                  Change in small entity status (see Article 1, BACKGROUND)





                                       12
<PAGE>



                  Addition of and/or participation in an affiliate

                  Existence of and/or participation in a joint venture

7.2               FIRST COMMERCIAL SALE: Within thirty (30) days following the
                  first commercial sale of each type of Licensed Product in the
                  U.S. and each country outside the U.S. by LICENSEE, LICENSEE
                  will report to THE REGENTS, at a minimum, the following
                  information:
                  License Number
                  Name of LICENSEE
                  Date of Report
                  Date of First Commercial Sale or Lease
                  Place of First Commercial Sale or Lease
                  Description of Licensed Products/Methods sold or leased
                  Licensed Patents and Licensed Copyrights practiced or
                  incorporated

7.3               QUARTERLY WRITTEN ROYALTY REPORTS: After the First Commercial
                  Sale of Licensed Products or Licensed Methods anywhere in the
                  world by LICENSEE, LICENSEE will submit quarterly written
                  royalty reports to THE REGENTS as follows:

                  DUE DATE                              FOR PREVIOUS PERIOD
                  --------                              -------------------

                  February 28                           October I - December 31
                  May 31                                January 1 - March 31
                  August 31                             April I - June 30
                  November 30                           July I - September 30

                  If LICENSEE has not sold or used any Licensed Products or
                  Licensed Methods during the reporting period, LICENSEE will so
                  state in the royalty report. The quarterly royalty report must
                  include at a minimum





                                       13
<PAGE>



                           the following information: License Number Name of
                           LICENSEE Date of Report Reporting period Report of
                           sales: For each type of Licensed Products/ Methods:
                           Name/ description of each type of product or process
                  A. Domestic sales:
                           1. Description of Licensed Products /Methods
                           2. Unit price (sale, lease, and/or use)
                           3. Units sold in U.S.
                           4. Units leased in U.S.
                           5. Gross sales in U.S.
                           6. Net Sales in U.S.
                           7. Accrued royalties
                           8. If Government approval requirements apply to
                           sale/use of the Licensed Product/Method (see Article
                           24, GOVERNMENT APPROVAL OR REGISTRATION), provide
                           details.
                  B. Foreign sales:
                           1. Country of sales
                           2. Description of Licensed Products /Methods
                           3. Unit price (sale, lease, and/or use)
                           4. Units sold in each country
                           5. Units leased in each country
                           6. Gross sales in each country
                           7. Net Sales in each country
                           8. Monetary exchange rate
                           9. Accrued royalties in $U.S.
                           10. If foreign government approval/ registration
                           requirements apply to sale/use of the Licensed
                           Product/Method (see Article 24, GOVERNMENT APPROVAL
                           OR REGISTRATION), provide details.




                                       14
<PAGE>



                  C. Government Sales:
                          1. Description of Licensed Products /Methods
                          2. Unit price (sale, lease, and/or use)
                          3. Units sold
                          4. Units leased
                          5. Gross sales
                          6. Net Sales to the Government

         Provide information A-C for each type of product or process sold

                  D. Royalties Due THE REGENTS

<TABLE>
<CAPTION>

                 MINIMUM ROYALTY PAID FOR    TOTAL ACCRUED ROYALTIES TO DATE
                    THIS CALENDAR YEAR            FOR THIS CALENDAR YEAR              ROYALTIES DUE
                 -------------------------   -------------------------------          -------------

<S>                      <C>                                                                <C>
7.4               LICENSEE will provide THE REGENTS with an annual audited
                  statement of royalty accounts within sixty (60) days after the
                  end of each calendar year. THE REGENTS will protect such
                  statements as Proprietary Information and not disseminate them
                  unless required by law.

7.5               LICENSEE will report in writing to THE REGENTS, within ten
                  (10) days of their occurrence, dates of the following events
                  pertaining to performance obligations specified in Exhibit B
                  (RIGHTS GRANTED AND PERFORMANCE OBLIGATIONS):

                  7.5.1    LICENSEE'S filings of relevant regulatory
                           applications pertaining to Licensed Products in
                           accordance with B.5.1.

                  7.5.2    Each grant of clearance by the FDA for Licensed
                           Products.



</TABLE>


                                       15
<PAGE>



                  7.5.3    LICENSEE'S compliance with performance obligations
                           specified in B.5.2, B.5.4, B.5.5, B.5.6, and B.5.7.

8.       BOOKS AND RECORDS

8.1               LICENSEE will keep books and records accurately showing the
                  manufacture, use, sale, and lease of Licensed Products,
                  Licensed Methods and Licensed Copyrights, and Sales of
                  Licensed Products under this Agreement. LICENSEE will preserve
                  such books and records for at least five (5) years after the
                  date of the royalty payment to which they apply. Such books
                  and records will be open for inspection by representatives or
                  agents of THE REGENTS at all reasonable times, with reasonable
                  notice given.

8.2               THE REGENTS will pay the costs incurred by its representatives
                  or agents to examine LICENSEE's books and records. If there is
                  an error adverse to THE REGENTS in LICENSEE'S royalty
                  accounting, then LICENSEE will pay THE REGENTS within ten (10)
                  days the amount necessary to correct such error. If there is
                  an error adverse to THE REGENTS in LICENSEE'S royalty
                  accounting of more than ten percent (10%) of the total
                  royalties due for any year, then LICENSEE will pay the costs
                  incurred by THE REGENTS' representatives and agents for such
                  examination.

8.3               LICENSEE will provide THE REGENTS with an annual audited
                  financial statement of LICENSEE, including at a minimum a
                  balance sheet and operating statement or LICENSEE'S annual
                  report. Such statement will be due to THE REGENTS within one
                  hundred twenty (120) days following the close of LICENSEE'S
                  fiscal year to which such statement relates.

9.       TERM





                                       16
<PAGE>



9.1               The term of this Agreement is the longer of either the term of
                  the license to Licensed Patents or the term of the license to
                  Licensed Copyrights.

9.2               The term of the license to Licensed Patents will commence on
                  the Effective Date and, unless terminated by operation of law
                  or by acts of the Parties under this Agreement, will remain in
                  effect until the expiration or abandonment of all Licensed
                  Patents.

9.3               The term of the license to Licensed Copyrights will commence
                  on the Effective Date and, unless terminated by operation of
                  law or by acts of the Parties under this Agreement, will
                  remain in effect for ten (10) years from January 14, 1999, the
                  date on which THE REGENTS received permission to assert
                  copyright. The term of the license to Licensed Copyrights may
                  be renewed for additional five-year periods for the life of
                  the copyright upon mutual written agreement of the Parties.

 10.     TERMINATION AND DISPOSITION OF LICENSED PRODUCTS

10.1              If LICENSEE fails to perform any material term or covenant of
                  this Agreement, THE REGENTS may give written notice to
                  LICENSEE that if LICENSEE has not cured such failure within
                  sixty (60) days after the effective date of receipt of the
                  notice, this Agreement will terminate at the end of such
                  sixty- (60) day period or at the end of such longer period as
                  may be set forth in THE REGENTS' notice.

10.2              LICENSEE may terminate this Agreement by giving at least
                  thirty (30) days prior written notice to THE REGENTS.




                                       17
<PAGE>



10.3              Termination of this Agreement will not relieve LICENSEE of any
                  obligation or liability accrued hereunder prior to such
                  termination, nor rescind any payments due or paid to THE
                  REGENTS prior to the time such termination becomes effective.
                  Such termination will not affect, in any manner, any rights of
                  THE REGENTS arising under this Agreement prior to such
                  termination. Any and all obligations of the Parties under this
                  Agreement will remain in effect until properly fulfilled or
                  otherwise discharged, notwithstanding the completion or early
                  termination of this Agreement.

10.4              Within thirty (30) days after termination of this Agreement by
                  either Party, LICENSEE will provide THE REGENTS with a written
                  inventory of all Licensed Products in process of manufacture
                  or in stock on the date of termination. LICENSEE may complete
                  Licensed Products in the process of manufacture at the time of
                  termination, and may dispose of Licensed Products for sixty
                  (60) days after the date of termination provided that LICENSEE
                  pays royalties to THE REGENTS on such dispositions. At the
                  conclusion of the sixty (60) day period, LICENSEE will destroy
                  any remaining Licensed Products in stock or in process of
                  manufacture and certify such destruction to THE REGENTS.

10.5              LICENSEE may not practice Licensed Patents or use Licensed
                  Copyrights after the date of termination of this Agreement
                  except as necessary to complete the manufacture of Licensed
                  Products as permitted under Article 10.4.

10.6              This Agreement will terminate, effective thirty (30) days
                  after the Effective date of notice by THE REGENTS, if LICENSEE
                  ceases to carry on its business.



                                       18
<PAGE>


11.      PATENT PROSECUTION AND MAINTENANCE

11.1              THE REGENTS will prosecute U.S. patent applications and
                  maintain U.S. patents licensed under this Agreement at THE
                  REGENTS' expense, unless otherwise agreed by the Parties.

11.2              LICENSEE may request foreign rights in Licensed Patents, if
                  such rights are available. Unless requested herein, LICENSEE
                  must request in writing such rights, and specify the countries
                  in which it wants rights, within seven (7) months after the
                  filing date of the U.S. applications. Failure to request such
                  rights will be considered an election not to seek foreign
                  rights. THE REGENTS may file patent applications at its own
                  expense in any country in which LICENSEE has not elected to
                  secure foreign rights, and LICENSEE has no rights to any such
                  foreign applications and resultant patents.

11.3              LICENSEE will pay all costs, including those incurred by THE
                  REGENTS prior to the Effective Date, associated with
                  preparation, filing, prosecution, and maintenance of Licensed
                  Patents in foreign countries in which LICENSEE obtains rights
                  under this Agreement. All Licensed Patents will be held in the
                  name of THE REGENTS and obtained using counsel selected by THE
                  REGENTS.

11.4              LICENSEE may terminate its license to foreign patent
                  applications or patents, and its obligation to pay any further
                  costs for those foreign rights, upon ninety (90) days written
                  notice to THE REGENTS. THE REGENTS or the Government may, at
                  its sole discretion and expense, continue prosecution and/or
                  maintenance of any patents or applications for which LICENSEE
                  has relinquished rights.




                                       19
<PAGE>


12.      PATENT AND COPYRIGHT INFRINGEMENT

12.1              If LICENSEE learns of the possible infringement by a third
                  party of any Licensed Patents or Licensed Copyrights, LICENSEE
                  will inform THE REGENTS in writing within thirty (30) days and
                  provide all known evidence of the infringement. LICENSEE will
                  not contact such third party concerning the infringement
                  without prior written approval of THE REGENTS. The Parties
                  will use their best efforts to terminate such infringement
                  without litigation.

12.2              LICENSEE may request in writing that THE REGENTS take legal
                  action against an infringer of any Licensed Patents or
                  Licensed Copyrights, which request must include reasonable
                  evidence of the infringement and of potential damages to
                  LICENSEE. Within one hundred (100) days after the date of
                  receipt by THE REGENTS of LICENSEE'S request, if the
                  infringement continues, THE REGENTS will notify LICENSEE in
                  writing that THE REGENTS will either:

                  12.2.1   Commence suit on its own account; or

                  12.2.2   Refuse to participate in such suit. LICENSEE may
                           thereafter bring suit for infringement at its own
                           expense if, and only if, THE REGENTS elects not to
                           commence suit and if the infringement occurred during
                           the period and in a jurisdiction where LICENSEE has
                           exclusive rights under this Agreement. However, in
                           the event LICENSEE elects to bring suit in accordance
                           with this Article, THE REGENTS may thereafter join
                           such suit at its own expense. If THE REGENTS elects
                           to not participate in such suit, LICENSEE may join
                           THE REGENTS in any suit in which THE REGENTS is a
                           necessary party for the suit to proceed, and if so
                           joined the




                                       20
<PAGE>



                           LICENSEE will pay all reasonable costs of THE REGENTS
                           associated with joining the suit as a necessary party
                           to the litigation.

12.3              Any legal or equitable action brought under this Article 12
                  will be at the expense of the Party bringing such legal or
                  equitable action and all recoveries will belong to such Party.
                  Legal or equitable action brought jointly by THE REGENTS and
                  LICENSEE and participated in by both will be at the joint
                  expense of the Parties in such proportions as are agreed to in
                  writing, and all recoveries will be shared by them in
                  proportion to the expense paid by each Party, or otherwise as
                  they may agree in writing.

12.4              The Parties will cooperate with each other in legal and
                  equitable proceedings instituted against an infringing third
                  party, but such cooperation by a Party will be at the expense
                  of the Party bringing such legal or equitable action; if both
                  Parties bring the action, the principles of Article 12.3 will
                  apply. Such legal or equitable action will be controlled by
                  the Party bringing the legal or equitable action, except that
                  THE REGENTS may be represented by counsel of its choice in any
                  action brought by LICENSEE.

13.      USE OF NAMES AND TRADEMARKS

                  Neither Party has any right to use any name, trade name,
                  trademark, or other designation of the other Party (including
                  any contraction, abbreviation, or simulation) in advertising,
                  publicity, or other promotional activities. Unless required by
                  law, the use of the name "Lawrence Livermore National
                  Laboratory," or "The Regents of the University of California,"
                  or the name of any University of California campus by



                                       21
<PAGE>



                  LICENSEE is expressly prohibited under California Education
                  Code ss.92000.

14.      LIMITED WARRANTY

14.1              THE REGENTS has the right to grant the license granted in this
                  Agreement.

14.2              THIS LICENSE AND THE ASSOCIATED INVENTIONS AND SOFTWARE ARE
                  PROVIDED WITHOUT WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
                  PARTICULAR PURPOSE OR ANY OTHER WARRANTY, EXPRESS OR IMPLIED.
                  THE REGENTS AND DOE MAKE NO REPRESENTATION OR WARRANTY THAT
                  LICENSED PRODUCTS OR LICENSED METHODS WILL NOT INFRINGE ANY
                  PATENT, COPYRIGHT OR OTHER PROPRIETARY RIGHT.

14.3              IN NO EVENT WILL THE REGENTS OR DOE BE LIABLE FOR ANY
                  INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES RESULTING FROM
                  EXERCISE OF THIS LICENSE OR THE USE OF THE SOFTWARE,
                  INVENTIONS, LICENSED METHODS, OR LICENSED PRODUCTS.

14.4              Nothing in this Agreement will be interpreted as:

                  14.4.1   A warranty or representation by THE REGENTS as to the
                           validity or scope of Licensed Patents or Licensed
                           Copyrights; or

                  14.4.2   A warranty or representation that anything made,
                           used, duplicated, displayed, performed, sold, or
                           otherwise disposed of





                                       22
<PAGE>



                           under the license granted in this Agreement is or
                           will be free from infringement of intellectual
                           property rights of third parties; or

                  14.4.3   Any obligation to bring suit against a third party
                           for patent or copyright infringement; or

                  14.4.4   Conferring by implication, estoppel, or otherwise any
                           license or rights under 1) any patents of THE REGENTS
                           other than Licensed Patents, regardless of whether
                           such patents are dominant or subordinate to Licensed
                           Patents or 2) any copyrights of THE REGENTS other
                           than Licensed Copyrights as defined in this
                           Agreement; or

                  14.4.5   An obligation to furnish to LICENSEE or any third
                           party any know-how, improvements, or Derivative Works
                           not specifically provided in this Agreement.

15.      INDEMNIFICATION

                  LICENSEE will, and will require its sublicensees to,
                  indemnify, hold harmless, and defend THE REGENTS, DOE, their
                  officers, employees, and agents; the sponsors of the research
                  that led to the Inventions and Software; and the inventors and
                  authors against any claims, suits, losses, liabilities,
                  damages, costs, fees, and expenses resulting from or arising
                  out of exercise of this license or any sublicense. LICENSEE
                  will pay any and all costs, including reasonable attorney
                  fees, incurred by THE REGENTS in enforcing this
                  indemnification.

16.      INSURANCE





                                       23
<PAGE>



16.1              LICENSEE will insure its activities relating to this Agreement
                  at its own cost with an insurance company acceptable to THE
                  REGENTS. LICENSEE will obtain, keep in force, and maintain
                  insurance as follows with an insurance company acceptable to
                  THE REGENTS or an equivalent program of self-insurance:
                  Comprehensive or Commercial Form General Liability Insurance,
                  including contractual liability and product liability, with
                  coverage as follows:

                  16.1.1   Each occurrence coverage of not less than One Million
                           Dollars ($1,000,000.00);

                  16.1.2   Product Liability Insurance: completed operations
                           aggregate coverage of not less than Ten Million
                           Dollars ($10,000,000.00);

                  16.1.3   Personal and Advertising Injury: coverage of not less
                           than One Million Dollars ($1,000,000.00); and

                  16.1.4   General Aggregate (Commercial Form Only): coverage of
                           not less than Five Million Dollars ($5,000,000.00).

                  These coverages do not limit the liability of LICENSEE to THE
                  REGENTS in any way. LICENSEE will provide THE REGENTS, upon
                  request, with certificates of insurance or self-insurance,
                  including renewals that show compliance with these
                  requirements. LICENSEE'S failure to maintain such required
                  insurance will be considered a material breach of this
                  Agreement.

16.2              If the required insurance is written on a claims-made form,
                  coverage must provide a retroactive date of placement before
                  or coinciding with the Effective Date of this Agreement.





                                       24
<PAGE>



16.3              LICENSEE will maintain the general liability insurance
                  specified in this Article16 during the period that the
                  Licensed Patents or Licensed Copyrights are being used and/or
                  Licensed Products are being sold or otherwise commercially
                  distributed by LICENSEE, and for a period of not less than
                  five (5) years thereafter.

16.4              LICENSEE'S insurance coverage must:

                  16.4.1   Provide for at least thirty (30) days advance written
                           notice to THE REGENTS of cancellation or any
                           modification;

                 16.4.2    Indicate that DOE, THE REGENTS, and their respective
                           officers, employees, students, and agents, are
                           endorsed on the policy as additional named insureds;
                           and

                 16.4.3    Include a provision that the coverage is primary and
                           does not participate with, or is in excess of, any
                           valid and collectible insurance, program, or
                           self-insurance carried or maintained by THE REGENTS.

17.      WAIVER

17.1              No provision of this Agreement is deemed waived and no breach
                  excused unless such waiver or consent is made in writing and
                  signed by the Party to have waived or consented.

17.2              Failure on the part of either Party to exercise or enforce any
                  right of such Party under this Agreement will not be a waiver
                  by such Party of any





                                       25
<PAGE>



                  right, or operate to bar the enforcement or exercise of the
                  right at any time thereafter.













































                                       26
<PAGE>




18.      ASSIGNABILITY

                  This Agreement is binding on and inures to the benefit of THE
                  REGENTS, its successors and assigns, but is personal to
                  LICENSEE. Any assignment or bankruptcy assumption of this
                  Agreement requires prior written consent of THE REGENTS which
                  consent shall not be unreasonably withheld.

 19.     LATE PAYMENTS

                  If THE REGENTS does not receive payments or fees due from
                  LICENSEE hereunder when due, LICENSEE must pay such payments
                  or fees within sixty (60) days plus interest charges at the
                  rate of ten percent (10%) simple interest per annum from the
                  date on which the payment was originally due, or THE REGENTS
                  may terminate this Agreement in accordance with its terms.

20.      NOTICES

                  Any report, payment, notice, or other communication that
                  either Party receives under this Agreement must be in writing
                  and will be properly given and effective on the date of
                  delivery if delivered in person (including delivery by courier
                  service), or the fifth (5th) day after mailing if mailed by
                  first-class certified mail, postage paid, to the addresses
                  given below (or to an address designated by written notice to
                  the other Party), or the date of facsimile with confirmed
                  receipt.




                                       27
<PAGE>

<TABLE>

<S>                                             <C>
In the case of LICENSEE:                     NOMOS Corporation
                                             2591 Wexford-Bayne Road
                                             Sewickley, PA 15143
                                             Phone: (724) 934-8200
                                             Fax: (724) 934-5488
                                             Attention: President

In the case of THE REGENTS:

All correspondence, original progress
reports, and royalty reports:                Lawrence Livermore, National Laboratory
                                             Industrial Partnership and
                                             Commercialization
                                             P.O. Box 808, L-795
                                             7000 East Ave., L-795
                                             Livermore, CA  94550
                                             Attention:  Director, IPAC
                                             Fax:  (925) 423-8988

Payments and copies of
corresponding royalty reports:               Lawrence Livermore National Laboratory
                                             P.O. Box 5517
                                             Livermore, CA 94550

</TABLE>

21.      DISPUTES AND GOVERNING LAWS

                  The Parties will attempt to jointly and promptly resolve any
                  disputes arising from this Agreement. If the Parties are
                  unable to resolve a dispute within a reasonable time from one
                  Party's written notice to the other that dispute resolution
                  has begun, then either Party may commence proceedings in a
                  court of competent jurisdiction. This Agreement will be
                  governed by the laws of the State of California, U.S.A.,
                  without regard to such State's conflict of laws provisions.

22.      PATENT MARKING




                                       28
<PAGE>



                  LICENSEE will mark all Licensed Products and their containers
                  that are made, used, sold, or otherwise disposed of under this
                  Agreement in accordance with applicable patent marking laws.

23.      COPYRIGHT MARKING

                  For all Licensed Products that incorporate Licensed
                  Copyrights, LICENSEE will affix to all copies of such Licensed
                  Products and their containers that are made, used, or sold or
                  otherwise distributed under this Agreement:

                  a)       the proper copyright notice in accordance with
                           applicable copyright marking laws; and

                  b)       the following notice:

                  "NOTICE: The Government is granted for itself and others
                  acting on its behalf a paid-up, nonexclusive, irrevocable,
                  worldwide license in this data to reproduce, prepare
                  Derivative Works, and perform publicly and display publicly.
                  Beginning ten (10) years after January 14, 1999, and subject
                  to any subsequent five (5) year renewals, the Government is
                  granted for itself and others acting on its behalf a paid-up,
                  nonexclusive, irrevocable, worldwide license in this data to
                  reproduce, prepare Derivative Works, distribute copies to the
                  public, perform publicly and display publicly, and to permit
                  others to do so. NEITHER THE UNITED STATES NOR THE UNITED
                  STATES DEPARTMENT OF ENERGY, NOR THE REGENTS OF THE UNIVERSITY
                  OF CALIFORNIA, NOR ANY OF THEIR EMPLOYEES, MAKES ANY WARRANTY,
                  EXPRESS OR IMPLIED, OR ASSUMES ANY LEGAL LIABILITY OR
                  RESPONSIBILITY





                                       29
<PAGE>



                  FOR THE ACCURACY, COMPLETENESS, OR USEFULNESS OF ANY
                  INFORMATION, APPARATUS, PRODUCT, OR PROCESS DISCLOSED, OR
                  REPRESENTS THAT ITS USE WOULD NOT INFRINGE PRIVATELY OWNED
                  RIGHTS."

24.      GOVERNMENT APPROVAL OR REGISTRATION

                  If this Agreement or any associated transaction is required by
                  the law of any jurisdiction to be approved, permitted, or
                  registered with any governmental agency, LICENSEE assumes all
                  obligations to do so. LICENSEE will notify THE REGENTS if
                  LICENSEE becomes aware that this Agreement is subject to a
                  United States or foreign government reporting, permitting, or
                  approval requirement. LICENSEE will make all necessary filings
                  and pay all costs including fees, penalties, and all other
                  out-of-pocket costs associated with such reporting,
                  permitting, or approval process.

 25.     EXPORT CONTROL LAWS

                  LICENSEE will comply with all applicable United States and
                  foreign laws and regulations concerning the transfer of
                  Licensed Products and related technical data, including but
                  not limited to International Traffic in Arms Regulations
                  (ITAR) and Export Administration Regulations.




                                       30
<PAGE>



26.      FORCE MAJEURE

                  The Parties will be excused from any performance required
                  hereunder if such performance is rendered impossible or
                  unfeasible due to any Acts of God, catastrophes, or other
                  major events beyond their reasonable control, including,
                  without limitation, war, riot, and insurrection; laws,
                  proclamations, edicts, ordinances, or regulations; strikes,
                  lock-outs, or other serious labor disputes; and floods, fires,
                  explosions, or other natural disasters. However, either Party
                  will have the right to terminate this Agreement pursuant to
                  this Article upon sixty (60) days prior written notice if
                  either Party is unable to fulfill its obligations under this
                  Agreement due to any of the causes mentioned above and such
                  inability continues for a period of one (1) year.

27.      UNITED STATES PREFERENCE

                  LICENSEE agrees that any Licensed Products and Licensed
                  Methods for applications, use, or sale shall be manufactured
                  substantially in the United States.

28.      PROPRIETARY INFORMATION

                  The term of the Mutual Nondisclosure Agreement (MNDA) between
                  the Parties, attached as Exhibit D (MUTUAL NONDISCLOSURE
                  AGREEMENT), is hereby extended for the term of this Agreement.
                  The confidentiality obligation of the MNDA will also apply to
                  any other Proprietary Information provided in connection with
                  this Agreement that is clearly marked in accordance with the
                  MNDA, such as patent prosecution, engineering drawings,
                  process and technical information,





                                       31
<PAGE>



                  and other related information not contemplated when the MNDA
                  was executed.

29.      MISCELLANEOUS

29.1              The headings of the Articles of this Agreement are for
                  reference only and do not affect the interpretation of this
                  Agreement.

29.2              Any amendment or modification of this Agreement must be in
                  writing and signed by each Party.

29.3              This Agreement, with the attached Exhibits A, B, C, and D,
                  embodies the entire understanding of the Parties with respect
                  to the subject matter of this Agreement, and supersedes all
                  other communications, representations, or understandings,
                  either oral or written, between the Parties with respect to
                  such subject matter.

29.4              If any provision of this Agreement is held to be invalid,
                  illegal, or unenforceable in any respect, such provision will
                  be enforced to the extent legally permissible and such
                  invalidity, illegality, or unenforceability will not affect
                  any other provisions of the Agreement, and this Agreement will
                  be construed as if the invalid, illegal, or unenforceable
                  provision, or relevant portion, were never in this Agreement.

29.5              Neither Party is an agent of the other and neither will have
                  any power to contract for or bind the other Party for any
                  purpose.

THE REGENTS and LICENSEE hereby execute this Agreement, in duplicate originals,
by their respective duly authorized officers.





                                       32
<PAGE>



<TABLE>
<S>                                                     <C>

NOMOS CORPORATION                                THE REGENTS OF THE
                                                 UNIVERSITY OF CALIFORNIA

                                                 LAWRENCE LIVERMORE
                                                 NATIONAL LABORATORY

By:            /s/ Anil Rastogi                  By:    /s/ J. Wadsworth
     ----------------------------------------           ------------------------------------------
                  (Signature)                                        (Signature)
Name:           Anil K. Rastogi                  Name:  Jeffrey Wadsworth
     ----------------------------------------           ------------------------------------------
Title:   President & CEO                         Title: Deputy Director for Science and Technology
      ---------------------------------------           ------------------------------------------

</TABLE>


Date Signed:  7/20/99                            Date Signed:  July 19, 1999























                                       33
<PAGE>




              EXHIBIT A - LICENSED PATENTS AND LICENSED COPYRIGHTS

THE LICENSED PATENTS ARE AS FOLLOWS:

UNITED STATES PATENTS GRANTED:
------------------------------

<TABLE>
<CAPTION>

INVENTION           PATENT                       TITLE                      INVENTORS           FILING        ISSUE
DISCLOSURE NUMBER   NUMBER                                                                      DATE          DATE
------------------- --------------- -------------------------------- ------------------------ ------------- --------------
<S>                 <C>                     <C>                         <C>                      <C>             <C>
IL-9839             5870697         Calculation of Radiation         William P. Chandler,        3/5/96        2/9/99
                                    Therapy Does Using all           Christine L.
                                    Particle Monte Carlo Transport   Hartmann-Siantar,
                                                                     James A. Rathkopf

</TABLE>

UNITED STATES PATENT APPLICATIONS:
----------------------------------

<TABLE>
<CAPTION>

INVENTION           PATENT                       TITLE                      INVENTORS         FILING        ISSUE
DISCLOSURE NUMBER   NUMBER                                                                    DATE          DATE
------------------- --------------- -------------------------------- ------------------------ ------------- --------------
<S>                 <C>                   <C>                           <C>                     <C>             <C>
IL-10165            09/082511       Evaluated Teletherapy Source     Lawrence J. Cox,            5/21/98        5/22/97
                                    Library (ETSL)                   Alexis E. Schach von
                                                                     Wittenau

IL-10350            09/23829        System and Method for            Paul M. Bergstrom,          1/28/99       11/12/98
                    1               Radiation Dose Calculation       Thomas Daly, Edward
                                    Within sub-Volumes of a          I. Moses, Ralph
                                    Monte Carlo Based                Patterson, Dewey
                                    Particle Transport Grid          Garrett, Ronald House,
                                                                     Christine Hartmann-
                                                                     Siantar, Lawrence J.
                                                                     Cox, Donald H. Fujino,
                                                                     Alexis E. Schach Von
                                                                     Wittenau


IL-10351            09/24765        FALCON:  Automated               Tser-Yuan Yang, Edward      2/9/99        9/10/98
                    1               Optimization for Arbitrary       I. Moses, Christine L.

</TABLE>


                                       34
<PAGE>


<TABLE>
<CAPTION>

                                    Criteria                         Hartmann-Siantar


PROVISIONAL PATENT APPLICATIONS:
--------------------------------

INVENTION           PATENT                       TITLE                      INVENTORS         FILING
DISCLOSURE NUMBER   NUMBER                                                                    DATE
------------------- ---------------- ------------------------------- ------------------------ -------------
<S>                   <C>                     <C>                         <C>                     <C>

IL-10472            60/123242        Correlated Histogram            Alexis E. Schach von        3/8/99
                                     Representation of Monte Carlo   Wittenau
                                     Derived Medical Accelerator
                                     Photon-Output Phase Spaces

</TABLE>

FOREIGN PATENTS GRANTED:  None
-----------------------

FOREIGN PATENT APPLICATIONS:
----------------------------

<TABLE>
<CAPTION>

INVENTION          PATENT                        TITLE                      INVENTORS         FILING
DISCLOSURE NUMBER  NUMBER                                                                     DATE
------------------ ----------------- ------------------------------- ------------------------ -------------

<S>                <C>                  <C>                               <C>                     <C>
IL-9839            97915859.9-EP     Calculation of Radiation        William P. Chandler,        3/5/96
                   All EP            Therapy Dose Using All          Christine L.
                   Countries         Particle Monte Carlo Transport  Hartmann-Siantar,
                                                                     James A. Rathkopf

IL-9839            531993/1997-JP    Calculation of Radiation        William P. Chandler,     2/28/97
                                     Therapy Does Using All          Christine L.
                                     Particle Monte Carlo Transport  Hartmann-Siantar,
                                                                     James A. Rathkopf

IL-9839            2248862-CA        Calculation of Radiation        William P. Chandler,     2/28/97
                                     Therapy Does Using All          Christine L.
                                     Particle Monte Carlo Transport  Hartmann-Siantar,
                                                                     James A. Rathkopf

</TABLE>

FUTURE PATENT RIGHTS
--------------------





                                       35
<PAGE>



Licensable WFO Subject Inventions will be added by amendment. THE LICENSED
COPYRIGHTS ARE AS FOLLOWS:

COPYRIGHT ASSERTION

PEREGRINE(TM), Version 1.1
1a.      Software Acronym:
         PEREGRINE.

1b.      Short Title:
         3D All Particle Monte Carlo code to calculate radiation dose delivered
         to cancer patients.

2.       Authors Names and Affiliations:
         Paul M. Bergstrom, William P. Chandler, Lila Chase, Larry J. Cox, Tom
         P. Daly, Don H. Fujino, Dewey. N. Garrett, Brian L. Guidry, Ron K.
         House, Don Y. Jong, Dave A. Knapp, Sarita S. May, Edward I. Moses,
         Clark. L. Powell, James A. Rathkopf, Christine L. Hartmann Siantar,
         Alexis E. Schach von Wittenau, Rosemary S. Walling, Steve 1. Warshaw,
         Jody A White, (LLNL).

3.       Software completion Date:  July 1999.
4.       Brief Description:
         PEREGRINE is a 3D All Particle Monte Carlo Code that calculates the
         dose to cancer patients from a variety of clinical radiation sources.
         PEREGRINE utilizes large nuclear, atomic, and electron databases, the
         patient CT scan data, and the Monte Carlo method to accurately
         calculate the dose delivered to a patient for photon teletherapy
         sources. The results of the dose calculation are then written to a file
         for graphical display over the CT scan data.

5.        Method of Solution:
          PEREGRINE uses conventional analog and condensed history Monte Carlo
          radiation transport methods to calculate dose three-dimensional dose
          distributions in the body. It reads input from standard treatment
          planning exchange files.

6.        Computer(s) for which software is written:
          UNIX workstation.




                                       36
<PAGE>



7.       Operating System:
         UNIX, Solaris.

8.       Programming Language(s) Used:
         Fortran (physical transport), C (1/0), Perl (scripting language used to
         run PEREGRINE), Tcl/Tk (scripting and control).

9.       Software Limitations:
         Must run on a UNIX workstation with >128MB RAM/CPU.

10.      Unique Features of the Software:
         PEREGRINE package includes a PEREGRINE Monte Carlo transport software,
         LLNL generated atomic data.

11.      Related and Auxiliary Software:
         None.

12.      Other Programming or Operating Information or Restrictions:
         None.

13.      Hardware Requirements:
         UNIX workstation with >128MB RAM/CPU.

14.      Time Requirements:
         Time requirements vary substantially with the complexity of the problem
         addressed.

Technical Description of Licensed Copyrights
--------------------------------------------
The files are:
libpg - PEREGRINE Monte Carlo library source files:
alias_sampling. F
alias_sampling_choice.F
check.F
direction_cosines.F
dose_mesh_data.F
electron_data.F
electron_physics.F






                                       37
<PAGE>


elpo_distribution.h
energy_groups.F
energy_groups.h
epsilon.h
file_io.F
form_factors.F
material_data.F
mesh_data.F
particle_attributes.h
particle_bank.F
particle_bank.h
particle_intercepts.F
pg_F pg_instantiate_device.F
pg_transport.F
photon_data.F
photon_physics.F
place_deposit.F
radial_function.F
random_numbers.F
random_numbers.h
source_data.F
source_electron_physics.F
source_geometry.F
source_particle.F
source_photon_physics.F
source_rejection.F
source_transport.F
timer.F track_particle.F
transform_coordinates.F
transform_coordinates.h
version_pglib.h

libtpi - Treatment Planning Interface source files:

beam_geometry.c
ct_scan.c
dose.c
dose_array.c
f77_Wrapper.c
inst_log_file.c
log_msg.c
runtime_diagnostics.c



                                       38
<PAGE>



scanner_data.c
structurex
tpi_support.c
tpi_support.h
version.h

libtsl - Teletherapy Source Library source files:

beam_device_compare.c
crc_checksum.c
device_data.c
f77_wrapper.c
fit_data.c
fit_data.d
instantiate_device.c
modify_one_device.c
pdt_data.c
runtime_option.c
transform_one_device.c
tsl_support.c
tsl_support.h

include - source files:

case_data.h
distributed_data.h
histo.h
material_data.h
pdt_data.h
pg.h
pg_constants.h
pg_exec.h
pg_types. h
physics_constants_h
runtime_options.h
timer.h
tpi.h
tsl.h
tuning_parameters.h

Single-Threaded test executive and utilities source files

Master Slave executive source files




                                       39
<PAGE>



FUTURE COPYRIGHT RIGHTS:
------------------------

Licensable WFO Computer Software will be added by amendment.




































                                       40
<PAGE>



         EXHIBIT B - RIGHTS GRANTED AND PERFORMANCE OBLIGATIONS

                                     NOTICE

             LICENSEE CONSIDERS INFORMATION IN THIS EXHIBIT B TO BE
                                  PROPRIETARY.

B.1               RIGHTS GRANTED

          B.1.1   Rights to Licensed Patents

                  Subject to the limitations set forth in this Agreement, THE
                  REGENTS hereby grants to LICENSEE an exclusive,
                  nontransferable, royalty-bearing license to: a) make, have
                  made, use, sell, offer for sale, and import Licensed Products
                  in the Field of Use, and b) practice Licensed Methods in the
                  Field of Use.

          B.1.2   Rights to Licensed Copyrights

                  Subject to the terms and conditions of this Agreement, THE
                  REGENTS grants to LICENSEE an exclusive, nontransferable,
                  royalty-bearing license to duplicate, display, perform, make
                  Derivative Works, distribute and have distributed, and sell
                  Licensed Products covered by Licensed Copyrights in the Field
                  of Use.

          B.1.3   "Field of Use" means planning human and animal cancer
                  therapies based on tumor irradiation with photons or electrons
                  that are generated either by a radiation source external to
                  the patient (teletherapy) or by a radiation source internal to
                  the patient (brachytherapy).

B.2               SUBLICENSING RIGHTS





                                       41
<PAGE>


         THE REGENTS also grants to LICENSEE the right to issue royalty-bearing
         sublicenses to third parties in the Field of Use, having rights no
         greater than those granted to LICENSEE, provided that LICENSEE has
         exclusive rights inb such Licensed Patents and Licensed Copyrights in
         the Field of Use at the time of sublicensing. A Use Sublicense is
         considered to be a Licensed Product and not a sublicense as
         contemplated in this B.2.

B.3               RIGHTS EXCLUDED

          Rights that are not specifically granted in this Exhibit B or
          elsewhere in this Agreement are specifically excluded from the
          license.

B.4               FUTURE RIGHTS

          Licensable WFO Subject Inventions and Licensable WFO Computer Software
          will be added to Exhibit A by amendment.

B.5               PERFORMANCE OBLIGATIONS

          B.5.1   LICENSEE will proceed diligently to develop, file relevant
                  regulatory applications for and attempt to obtain relevant
                  regulatory commercialization approvals with respect to the
                  manufacturing, marketing, and sale of Licensed Products for
                  all uses in the Field of Use. LICENSEE will file with the U.S.
                  Food and Drug Administration at least one 510k Application or
                  PMA (Pre-Market Approval) for clearance of Licensed Products
                  for at least teletherapy uses within one (1) year of the
                  Effective Date. Notwithstanding any other term of this
                  Agreement, for the purposes of (a) invoking/ complying with
                  the Hatch-Waxman Act (35 U.S.C.ss.156) and any corresponding
                  rules and regulations of the U.S.



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<PAGE>



                  Patent & Trademark Office regarding patent term extension, and
                  (b) seeking regulatory approval of LICENSEE'S Licensed
                  Products and Licensed Methods, LICENSEE shall act as THE
                  REGENTS' agent. To the extent deemed necessary by LICENSEE, in
                  good faith, the Parties will cooperate to secure regulatory
                  approval of LICENSEE'S Licensed Products and Licensed Methods.

          B.5.2   LICENSEE will release for distribution and offer Sales of
                  Licensed Products by the later date of either October 1, 2000,
                  or within sixty (60) days after the date of FDA clearance for
                  teletherapy uses of Licensed Products.

          B.5.3   LICENSEE will have gross revenues from Sales of Licensed
                  Products or use of Licensed Methods of at least Three Million
                  Dollars ($3,000,000.00) per calendar year, as measured at the
                  close of LICENSEE's business on

                  December 31 of the relevant calendar year, commencing with the
                  later of calendar year 2001, or the first full calendar year
                  after a Licensed Product has been released for distribution
                  and offered for sale in accordance with paragraph B.5.2.

          B.5.4   LICENSEE will release for distribution and offer first OEM
                  sale of Licensed Products that interface with radiation
                  treatment planning systems that are manufactured and sold, or
                  otherwise distributed to third parties, by entities other than
                  LICENSEE by the later date of either

                  October 1, 2001, or one year after initial release for
                  distribution and offer of Sales of Licensed Products as
                  defined in B.5.2. To the extent that some commercial entities
                  may prefer to sublicense Licensed Patents and



                                       43
<PAGE>



                  Licensed Copyrights rather than to purchase Licensed Products
                  on an OEM basis, LICENSEE'S sublicenses may satisfy this OEM
                  performance obligation.

          B.5.5   LICENSEE will release for distribution and offer first sale of
                  Licensed Products in the Field of Use for brachytherapy by the
                  later date of either October 1, 2002, or within sixty (60)
                  days after the date of FDA clearance for brachytherapy uses of
                  Licensed Products.

          B.5.6   LICENSEE will release for distribution and offer first sale of
                  Licensed Products in the Field of Use for inverse treatment
                  planning by the later date of either October 1, 2002, or
                  within sixty (60) days after the date of FDA clearance for
                  inverse treatment planning uses of Licensed Products.

          B.5.7   LICENSEE will release for distribution and offer first sale of
                  Licensed Products in the Field of Use for electron
                  radiotherapy by the later date of either October 1, 2002, or
                  within sixty (60) days after the date of FDA clearance for
                  electron radiotherapy uses of Licensed Products.

          B.5.8   The sales and other performance requirements specified above
                  may, by mutual written consent of LICENSEE and THE REGENTS, be
                  amended and/or extended at the written request of LICENSEE to
                  THE REGENTS, based upon legitimate business or technical
                  reasons specified in reasonable detail in such written
                  request. THE REGENTS will not unreasonably withhold its
                  consent to requests made in accordance with this paragraph.

          B.5.9   ThefirstprogressreportwillbedueonFebruary28,2000.

B.6           OPTION RIGHT



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<PAGE>



         THE REGENTS also grants to LICENSEE an option to negotiate terms under
         which THE REGENTS will add protons, neutrons or both particles to the
         Field of Use as otherwise defined in B.1.3 above (Option). The term of
         the Option will be eighteen (18) months from the Effective Date.
         LICENSEE may exercise this Option by providing THE REGENTS a written
         plan (Plan) for the development and commercialization of Licensed
         Products in the expanded Field of Use (Expanded FOU) which Plan is
         acceptable to THE REGENTS. LICENSEE will provide the Plan as soon as
         practical, but in no case later than fifteen (15) months after the
         Effective Date. Upon exercise of the Option, and acceptance of the Plan
         by THE REGENTS, THE REGENTS will negotiate in good faith terms for the
         Expanded FOU. Terms will include, but not be limited by, specific
         performance obligations of LICENSEE pertaining to regulatory approvals
         and sales of Licensed Products in the Expanded FOU and additional fees,
         royalties, or other compensation for the rights obtained by LICENSEE
         under the Option.
























                                       45
<PAGE>




                         EXHIBIT C - FEES AND ROYALTIES

                                     NOTICE

       LICENSEE CONSIDERS INFORMATION IN THIS EXHIBIT C TO BE PROPRIETARY.

C.1               LICENSE ISSUE FEE

           C.1.1  As partial consideration for this Agreement, LICENSEE will pay
                  to THE REGENTS a nonrefundable issue fee of Three Hundred
                  Thousand Dollars ($300,000.00) (License Issue Fee) as follows:

                  C.1.1.1  Fifty Thousand Dollars ($50,000.00) to be paid when
                           LICENSEE executes the Agreement.

                   C.1.1.2 Fifty Thousand Dollars ($50,000.00) to be paid no
                           later than October 1, 1999.

                   C.1.1.3 Fifty Thousand Dollars ($50,000.00) to be paid no
                           later than November 1, 1999.

                   C.1.1.4 Fifty Thousand Dollars ($50,000.00) to be paid no
                           later than December 1, 1999.

                   C.1.1.5 Fifty Thousand Dollars ($50,000.00) to be paid no
                           later than January 1, 2000.

                   C.1.1.6 Fifty Thousand Dollars ($50,000.00) to be paid no
                           later than February 1, 2000.




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<PAGE>



          C.1.2    THE REGENTS will execute the Agreement after receipt of
                  LICENSEE'S executed copies of the Agreement and payment of the
                  first installment of the License Issue Fee specified in
                  C.1.1.1 above.

          C.1.3    The License Issue Fee will not be credited against any other
                  royalty or fee due from LICENSEE to THE REGENTS.

          C.1.4    In the event that LICENSEE grants sublicenses, LICENSEE will
                  collect an issue fee equal to or greater than the License
                  Issue Fee. LICENSEE will pay to THE REGENTS fifty percent
                  (50%) of any issue fee from sublicensing.

C.2       EARNED ROYALTIES

        In addition to the License Issue Fee, LICENSEE will pay THE REGENTS an
        earned royalty equal to eight percent (8%) of Net Sales by LICENSEE and
        any sublicensees. The earned royalty on sales of any Licensed Product
        that is sold as part of a larger product system, shall be based on the
        average Net Sales of that Licensed Product sold separately on a non-OEM
        basis over the relevant royalty reporting period. For the purposes of
        calculating earned royalties, the minimum value of any License Product
        shall be Fifty Thousand Dollars ($50,000.00) for the first two (2) full
        years after the date of initial release for distribution and offer of
        Sales of Licensed Products as specified in B.5.2. The minimum value
        shall be Thirty-Five Thousand Dollars ($35,000.00) for the next two (2)
        full years, and Twenty-Five Thousand Dollars ($25,000.00) thereafter.

        In the event that LICENSEE terminates the WFO without cause and without
        funding sufficient to complete the tasks and deliverables specified in
        Phase I (Technology Transfer and Clinical Implementation) of Attachment
        A to the WFO, the royalty rate specified above will be ten percent
        (10%).




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<PAGE>



        Payments of earned royalties will be in accordance with the requirements
        of Article 4.2 (SUBLICENSING RIGHTS AND OBLIGATIONS), Article 5 (FEES,
        ROYALTIES AND PAYMENTS) and Article 7 (PROGRESS AND ROYALTY REPORTS) of
        this Agreement.

C.3               MAINTENANCE FEES

         Beginning in calendar year 2000, LICENSEE will pay THE REGENTS a
         license maintenance fee of Thirty Five Thousand Dollars ($35,000.00)
         per calendar year, which will be due according to the schedule in CA.
         The maintenance fee in any calendar year will be creditable against the
         minimum annual royalty due in the same calendar year.

C.4               MINIMUM ANNUAL ROYALTIES

         LICENSEE will pay to THE REGENTS a minimum annual royalty according to
         the requirements of Article 5 (FEES, ROYALTIES AND PAYMENTS) and the
         schedule below. Earned royalties paid to THE REGENTS for Net Sales
         during a calendar year will be accrued and credited against the minimum
         annual royalty paid for that same calendar year.

<TABLE>

             CALENDAR YEAR               MINIMUM ANNUAL ROYALTY                 DUE DATE IN CALENDAR YEAR
             -------------               ----------------------                 -------------------------
<S>              <C>                     <C>                                                          <C>
                 2000                           $35,000.00                             February 28
                 2001                          $135,000.00                             February 28
                 2002                          $200,000.00                             February 28
                 2003                          $250,000.00                             February 28
                 2004                          $325,000.00                             February 28
  2005 and thereafter for the life of          $400,000.00                             February 28
            this Agreement


</TABLE>





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<PAGE>















































                                       49
<PAGE>








                  EXHIBIT D - MUTUAL NONDISCLOSURE AGREEMENT




































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