EXHIBIT
      10.1

    


    SECOND
      AMENDMENT

    TO
      

    LOAN
      AND SECURITY AGREEMENT

    


    THIS
      SECOND AMENDMENT to
      Loan and Security Agreement
      (this “Amendment”)
      is entered into on October 31, 2006, by and between 

     

    SILICON
      VALLEY BANK (“Bank”)

     

    and
      the
      following (collectively, jointly and severally, the "Borrower") whose address
      is
      20200 Sunburst Street, Chatsworth, California 91311: 

     

    NORTH
      AMERICAN SCIENTIFIC,
      INC., a
      Delaware corporation (“NASI”);

     

    NORTH
      AMERICAN SCIENTIFIC, INC., a California corporation (“NASI-CA”);
      and

     

    NOMOS
      CORPORATION, a Delaware corporation (“NOMOS”).

     

    .

     

    Recitals

     

    A. Bank
      and
      Borrower have entered into that certain Loan and Security Agreement, with an
      Effective Date of October 5, 2005 (as the same has been, and may hereafter
      from
      time to time be amended, modified, supplemented or restated, the “Loan
      Agreement”). The Loan Agreement was amended by that certain First Amendment to
      Loan and Security Agreement dated January 12, 2006 (the “First
      Amendment”).

     

    B. Bank
      has
      extended credit to Borrower for the purposes permitted in the Loan Agreement.
      

     

    C. The
      parties desire to amend the Loan Agreement as herein set forth.

     

    Agreement

     

    Now,
      Therefore,
      in
      consideration of the foregoing recitals and other good and valuable
      consideration, the receipt and adequacy of which are hereby acknowledged, and
      intending to be legally bound, the parties hereto agree as follows:

     

    1.  Definitions.
      Capitalized terms used but not defined in this Amendment shall have the meanings
      given to them in the Loan Agreement.

     

    2.  Amendments
      to Loan Agreement. The
      Loan
      Agreement is hereby amended as follows, effective on October 31,
      2006:

     

    
      
        
        

      

      
        1

        
          

        

      

      
        
        

      

    

    2.1  Amended
      and Restated Schedule 2.
      Schedule 2 to the Loan Agreement is amended and restated to read as set forth
      in
      the Amended and Restated Schedule 2 to Loan and Security Agreement, which is
      being signed by Borrower and Bank concurrently herewith.

     

    2.2  Certain
      Definitions.
      The
      following definitions are added to Section 13.1 of the Loan Agreement, in
      alphabetical order:

     

    “‘Quick
      Ratio Test’.
      As used
      herein, the ‘Quick Ratio Test’ will be deemed to be met if Borrower’s Adjusted
      Quick Ratio at the end of August, 2006 and at the end of each subsequent month
      is at least 1.00 to 1.00. If at the end of any such subsequent month Borrower’s
      Adjusted Quick Ratio is not at least 1.00 to 1.00, then Borrower shall not
      thereafter be deemed to meet the Quick Ratio Test, unless Borrower’s Adjusted
      Quick Ratio is at least 1.00 to 1.00 for a subsequent continuous period,
      continuous to the date of determination, and such continuous period is at least
      three calendar months. As used herein, “Adjusted Quick Ratio” means the ratio of
      (i) Borrower’s unrestricted cash plus Borrower’s net Accounts to (ii) the total
      of Borrower’s current liabilities (including all of the Obligations to
      Bank).”

     

    “
      ‘Reduced
      Borrowing Test’.
      As used
      herein, the ‘Reduced Borrowing Test’ will be deemed to be met on a day if, on
      such day, the total of (i) the outstanding Advances, plus the outstanding
      Letters of Credit (including drawn but unreimbursed Letters of Credit), plus
      the
      FX Reserve, plus the outstanding Obligations relating to Cash Management
      Services, is less than (ii) 50% of the Borrowing Base (without regard to the
      Revolving Line Credit Amount).”

     

    2.3  Audits.
      Section
      6.2(d) of the Loan Agreement, which presently reads as follows

     

    
      	 	
              
                “(d)  
                  Allow Bank to audit Borrower's Collateral at Borrower's
                  expense,
                  with the first of such audits to be completed, with results satisfactory
                  to Bank prior to the making of any Advances hereunder (it being
                  understood
                  that Bank has heretofore conducted an audit of Borrower’s Collateral).
                  After the initial audit, such audits will be conducted no more
                  often than
                  every 6 months, unless an Event of Default or Default has occurred
                  and is
                  continuing and in such event there shall be no limitation as to
                  the
                  frequency of audit conducted. Further, upon the effectiveness of
                  the Asset
                  Based Terms, an audit shall be conducted within 90 days of the
                  effectiveness thereof and subsequent audits shall be conducted
                  on a
                  quarterly basis or at such other frequency as the conditions warrant
                  as
                  Bank shall determine in its good faith business judgment (unless
                  there are
                  no Credit Extensions outstanding and Borrower has not requested
                  that Bank
                  extend any Credit Extensions hereunder and in such case audits
                  shall be
                  conducted not more frequently than quarterly, or as Bank shall
                  reasonably
                  determine as conditions warrant). In connection with Bank’s field audits,
                  Borrower shall pay to Bank the sum of $750 per day during such
                  audit, plus
                  Bank’s reasonable out of pocket expenses incurred in connection
                  therewith.”

              

            	 


    

     

    
      
        
        

      

      
        2

        
          

        

      

      
        
        

      

    

    is
      amended to read as follows:

     

    
      	 	
              “(d)  
                Allow
                Bank to audit Borrower's Collateral at Borrower's expense. Such audits
                will be conducted no more often than every 6 months, provided that
                (i) if
                the Quick Ratio Test is not met, such audits will be conducted no
                more
                often than every 3 months, and (ii) if an Event of Default or Default
                has
                occurred and is continuing there shall be no limitation as to the
                frequency of audit conducted. In connection with Bank’s field audits,
                Borrower shall pay to Bank the sum of $750 per day during such audit,
                plus
                Bank’s reasonable out of pocket expenses incurred in connection
                therewith.”

            	 


    

     

    2.4  Collection
      of Accounts.
      The
      portion of Section 2 of Exhibit E to the Loan Agreement, which presently reads
      as follows:

     

    
      
        	 	
                “(2)  
                  Collection
                  of Accounts. Borrower shall hold all payments on, and proceeds
                  of,
                  Accounts and all other Collateral in trust for Bank, and Borrower
                  shall
                  immediately deliver all such payments and proceeds to Bank in their
                  original form, duly endorsed, to be applied to the Obligations
                  in such
                  order as Bank shall determine. Borrower agrees that it will not
                  commingle
                  such payments and proceeds with any of Borrower's other funds or
                  property,
                  but will hold such payments and proceeds separate and apart from
                  such
                  other funds and property and in an express trust for Bank. Bank
                  may, in
                  its discretion, require that all proceeds of Collateral be deposited
                  by
                  Borrower into a lockbox account, or such other "blocked account"
                  as Bank
                  may specify, pursuant to a blocked account agreement in such form
                  as Bank
                  may specify.”

              	 


      

       

    

    is
      amended to read as follows:

     

    
      
        	 	
                “(2)  
                  Collection
                  of Accounts. Borrower shall direct all Account Debtors to make
                  payment of
                  all Accounts directly to a lockbox established with Bank (the ‘Lockbox’).
                  Borrower shall hold all payments on, and proceeds of, Accounts
                  and all
                  other Collateral in trust for Bank, and Borrower shall immediately
                  deposit
                  all such payments and proceeds in the Lockbox. All sums received
                  in the
                  Lockbox shall be transferred by Bank to Borrower’s operating account at
                  Bank, provided
                  that
                  if, at any time, the Quick Ratio Test is not met and the Reduced
                  Borrowing
                  Test is not met, then
                  all sums received in the Lockbox shall be applied by Bank to the
                  Obligations in such order as Bank shall determine, and any excess
                  shall be
                  transferred by Bank to Borrower’s operating account at
                  Bank.”

              	 


      

       

    

    2.5  “Float”.
      The
      portion of Section 3 of Exhibit E to the Loan Agreement, which presently reads
      as follows

     

    
      
        	 	
                “(3)  
                  Interest
                  Computation. In computing interest on the Obligations, all checks,
                  wire
                  transfers and other items of payment received by Bank (including
                  proceeds
                  of Accounts shall be deemed applied by Bank on account of the Obligations
                  two Business Days after receipt by Bank of immediately available
                  funds,
                  and, for purposes of the foregoing, any such funds received after
                  12:00
                  Noon (Pacific Time) on any day shall be deemed received on the
                  next
                  Business Day.”

              	 


      

       

      
        
          
          

        

        
          3

          
            

          

        

        
          
          

        

      

    

    is
      amended to read as follows:

     

    
      	 	
              
                “(3)  
                  Interest Computation. In computing interest on the Obligations,
                  all
                  checks, wire transfers and other items of payment received by Bank
                  (including proceeds of Accounts) shall be deemed applied by Bank
                  on
                  account of the Obligations on receipt by Bank of immediately available
                  funds, and, for purposes of the foregoing, any such funds received
                  after
                  12:00 Noon (Pacific Time) on any day shall be deemed received on
                  the next
                  Business Day, provided
                  that
                  if, at any time, the Quick Ratio Test is not met, and the Reduced
                  Borrowing Test is not met, then
                  in
                  computing interest on the Obligations, all checks, wire transfers
                  and
                  other items of payment received by Bank (including proceeds of
                  Accounts)
                  shall be deemed applied by Bank on account of the Obligations two
                  Business
                  Days after receipt by Bank of immediately available funds, and,
                  for
                  purposes of the foregoing, any such funds received after 12:00
                  Noon
                  (Pacific Time) on any day shall be deemed received on the next
                  Business
                  Day.

              

            	 


    

     

    2.6  Other
      Reporting Requirements.
      The
      following is hereby added to Exhibit E to the Loan Agreement at the end of
      Section (7) thereof, following subparagraph 8:

     

    “9.
      Annual financial projections for each fiscal year, approved by Borrower’s Board
      of Directors (including income statement, balance sheet and cash flow) no later
      than 30 days after the beginning of such fiscal year and interim updates thereto
      as requested by Bank.

     

    
      
        	 	
                10.  
                  If,
                  at the time, the Quick Ratio Test is met or the Reduced Borrowing
                  Test is
                  met, a Transaction Report within 30 days after the end of each
                  month.

              	 


      

       

    

    2.7  Transaction
      Reports.
      The
      following is hereby added at the end of Exhibit E to the Loan
      Agreement:

     

    “(8)
      Transaction Reports. Notwithstanding the foregoing, Transaction Reports will
      not
      be required weekly, if, at the time, the Quick Ratio Test is met or the Reduced
      Borrowing Test is met. Even if weekly Transaction Reports are not required,
      a
      Transaction Report will be required at the time of a request for an
      Advance.”

     

    2.8  Exhibit
      E Continues Effective.
      As
      provided in the First Amendment, Exhibit E to the Loan Agreement (as modified
      by
      this Amendment) continues to be effective and operative.

     

    2.9  Exhibit
      D. Exhibit
      D
      to the Loan Agreement, the form of Compliance Certificate, is hereby replaced
      by
      Exhibit D hereto.

     

    
      
        
        

      

      
        4

        
          

        

      

      
        
        

      

    

    2.10  Subsidiary.
      The
      portion of the definition of “Permitted Investments” in Section 13.1 of the Loan
      Agreement, which presently reads: “Theseus Imaging Corporation, a current
      domestic subsidiary of NASI which Borrower represents to Bank will be dissolved
      no later than October 31, 2006,” is amended to read:

     

    “Theseus
      Imaging Corporation, a current domestic subsidiary of NASI which Borrower
      represents to Bank will be dissolved no later than July 31, 2007,”

     

    


    3.  Limitation
      of Amendments.

     

    3.1  The
      amendments set forth in Section 2, above, are effective for the purposes
      set forth herein and shall be limited precisely as written and shall not be
      deemed to (a) be a consent to any amendment, waiver or modification of any
      other term or condition of any Loan Document, or (b) otherwise prejudice
      any right or remedy which Bank may now have or may have in the future under
      or
      in connection with any Loan Document.

     

    3.2  This
      Amendment shall be construed in connection with and as part of the Loan
      Documents and all terms, conditions, representations, warranties, covenants
      and
      agreements set forth in the Loan Documents, except as herein amended, are hereby
      ratified and confirmed and shall remain in full force and effect.

     

    4.  Representations
      and Warranties.
      To
      induce Bank to enter into this Amendment, Borrower hereby represents and
      warrants to Bank as follows:

     

    4.1  Immediately
      after giving effect to this Amendment (a) the representations and
      warranties contained in the Loan Documents are true, accurate and complete
      in
      all material respects as of the date hereof (except to the extent such
      representations and warranties relate to an earlier date, in which case they
      are
      true and correct as of such date), and (b) no Event of Default has occurred
      and is continuing;

     

    4.2  Borrower
      has the corporate power and authority to execute and deliver this Amendment
      and
      to perform its obligations under the Loan Agreement, as amended by this
      Amendment;

     

    4.3  The
      organizational documents of Borrower delivered to Bank on the Effective Date
      remain accurate and complete and have not been amended, supplemented or restated
      since the Effective Date and are, and continue to be, in full force and
      effect;

     

    4.4  The
      execution and delivery by Borrower of this Amendment and the performance by
      Borrower of its obligations under the Loan Agreement, as amended by this
      Amendment, have been duly authorized; 

     

    4.5  The
      execution and delivery by Borrower of this Amendment and the performance by
      Borrower of its obligations under the Loan Agreement, as amended by this
      Amendment, do not and will not contravene (a) any law or regulation binding
      on or affecting Borrower, (b) any material agreement by which Borrower or
      its property is bound, (c) any order, judgment or decree of any court or
      other governmental or public body or authority, or subdivision thereof, binding
      on Borrower, or (d) the organizational documents of Borrower; 

     

    
      
        
        

      

      
        5

        
          

        

      

      
        
        

      

    

    4.6  The
      execution and delivery by Borrower of this Amendment and the performance by
      Borrower of its obligations under the Loan Agreement, as amended by this
      Amendment, do not require any order, consent, approval, license, authorization
      or validation of, or filing, recording or registration with, or exemption by
      any
      governmental or public body or authority, or subdivision thereof, binding on
      either Borrower, except as already has been obtained or made; and

     

    4.7  This
      Amendment has been duly executed and delivered by Borrower and is the binding
      obligation of Borrower, enforceable against Borrower in accordance with its
      terms, except as such enforceability may be limited by bankruptcy, insolvency,
      reorganization, liquidation, moratorium or other similar laws of general
      application and equitable principles relating to or affecting creditors’
rights.

     

    4.8  The
      written report as to the status of certain litigation, which was provided by
      Borrower to Bank in connection with this Amendment, shall be deemed part of
      the
      Perfection Certificate dated September 25, 2006 provided by Borrower to
      Bank.

     

    5.  Counterparts.
      This
      Amendment may be executed in any number of counterparts and all of such
      counterparts taken together shall be deemed to constitute one and the same
      instrument.

     

    6.  Effectiveness.
      This
      Amendment shall be deemed effective upon the due execution and delivery of
      this
      Amendment by each party hereto.

     

     

    [Signature
      page follows.]

     

    
      
        
        

      

      
        6

        
          

        

      

      
        
        

      

       

    

    In
      Witness Whereof, the
      parties hereto have caused this First Amendment to be duly executed and
      delivered as of the date first written above.

    


    
      	
              “Borrower”:

               

              NORTH
                AMERICAN SCIENTIFIC, INC.

              A
                Delaware corporation

               

               

              By      
                /s/L.Michael
                Cutrer             
                

              President
                or Vice President

               

               

            	
              “Bank”:

               

              SILICON
                VALLEY BANK

               

               

               

              By      
                /s/Kurt
                Miklinski                       
                

              Title 
                   Vice
                President                         
                

            
	
              “Borrower”:

               

              NORTH
                AMERICAN SCIENTIFIC, INC.

              A
                California corporation

               

               

              By 
                /s/L.Michael
                Cutrer     
                

              President
                or Vice President

               

            	 
	
              “Borrower”:

               

              NOMOS
                CORPORATION

               

               

              By      
                /s/L.Michael
                Cutrer              
                

              President
                or Vice President

            	 


    

    


    
      
        
        

      

      
        7

        
          

        

      

      
        
        

      

    


    EXHIBIT
      D

    COMPLIANCE
      CERTIFICATE

    


    
      	TO:	
              SILICON
                VALLEY BANK

            


    

    38
      Technology Drive, Suite 150 

    Irvine,
      CA 92618

    


    
      	FROM:	
              North
                American Scientific, Inc.,
                a Delaware corporation

            


    

    North
      American Scientific, Inc.,
      a
      California corporation; and

    NOMOS
      Corporation,
      a
      Delaware corporation

    


    


    The
      undersigned authorized officers of each of North
      American Scientific, Inc., a Delaware corporation, North American Scientific,
      Inc., a California corporation, and NOMOS Corporation
      (collectively “Borrower”) certifies that under the terms and conditions of the
      Loan and Security Agreement between Borrower and Bank (the “Agreement”),
      (i) Borrower is in complete compliance for the period ending
      _______________ with all required covenants except as noted below and
      (ii) all representations and warranties in the Agreement are true and
      correct in all material respects on this date, provided that any representations
      and warranties expressly referring to another date are true and correct in
      all
      material respects as of such other date. In
      addition, the undersigned certifies that (1) Borrower has timely filed all
      required tax returns and paid, or made adequate provision to pay, all material
      taxes, except those being contested in good faith with adequate reserves under
      GAAP and (2) no liens have been levied or claims made against Borrower relating
      to unpaid employee payroll or benefits which Borrower has not previously
      notified in writing to Bank. Attached
      are the required documents supporting the certification. The Officer certifies
      that these are prepared in accordance with Generally Accepted Accounting
      Principles (GAAP) consistently applied from one period to the next except as
      explained in an accompanying letter or footnotes. The Officer acknowledges
      that
      no borrowings may be requested at any time or date of determination that
      Borrower is not in compliance with any of the terms of the Agreement, and that
      compliance is determined not just at the date this certificate is
      delivered.

    


    Please
      indicate compliance status by circling Yes/No under “Complies”
column.

    


    
      	
              Reporting
                Covenant

            	 	
              Required

            	 	
              Complies

            
	
              Monthly
                financial statements + CC

            	 	
              Monthly
                within 30 days

            	 	
              
                Yes

              

            	No	N/A
	
              Quarterly
                Reports on Form 10-Q

            	 	
              Within
                5 days of filing to the SEC

            	 	
              
                Yes

              

            	No	N/A
	
              Annual
                Report on Form 10-K (Audited)

            	 	
              FYE
                within 5 days of filing with the SEC

            	 	
              
                Yes

              

            	No	N/A
	
              A/R
                & A/P Agings

            	 	
              Monthly
                w/in 15 days 

            	 	
              
                Yes

              

            	No	N/A
	
              Weekly
                transactions reports and schedules of collections (when required
                under
                Loan Agreement)

            	 	
              Weekly

            	 	
              Yes

            	No	N/A
	
              Monthly
                reconciliations of A/R agings, Transaction Reports and general ledger
                

            	 	
              Monthly
                within 30 days

            	 	
              Yes

            	No	N/A
	 	 	 	 	 	 	 
	
              Financial
                Covenant

            	 	
              Required

            	
              Actual

            	
              Complies

            
	 	 	 	 	 	 	 
	
              Maintain
                at all times and measured on a monthly basis: Minimum Tangible Net
                Worth

            	 	
              $5,000,000
                

            	
              $______________

               

            	
              Yes 

            	No	N/A


    

    


    
      
        
        

      

      
        8

        
          

        

      

      
        
        

      

       

    

    Borrower
      only has deposit accounts located at the following institutions:
      ___________________. 

    


    Has
      Borrower filed any new Trademark, Patent or Copyright applications? Yes
      /
      No

    (If
      “yes”, please list below and complete the attached Addendum to Intellectual
      Property Security Agreement)

    


    Trademarks:
      ___________________________________________________

    


    Patents:
      _______________________________________________________

    


    Copyrights:
      ______________________________________________________

    


    Comments
      Regarding Exceptions:
      See
      Attached.

    


     

    


    
      	 	 	
               BANK
                USE
                ONLY

            
	North American Scientific,
              Inc.	 	Received
              by:                                                         
              
	A Delaware
              corporation	 	
              AUTHORIZED
                SIGNER

            
	 	 	 
	By:     	 	Date:                                                                     
              
	
              Authorized
                Signer

            	 	 
	 	 	 
	 	 	Verified:                                                               
              
	North American Scientific,
              Inc.	 	
              AUTHORIZED
                SIGNER

            
	 A California
              corporation	 	 
	 	 	Date:                                                                     
              
	 	 	 
	By:     	 	 Compliance Status:   
              Yes          No
	
              Authorized
                Signer

            	 	 


    

     

     

     

    
      
        
        

      

      
        9

        
          

        

      

      
        
        

      

    

     

    NOMOS
      Corporation

    A
      Delaware corporation

    


    


    By:     

    Authorized
      Signer

     

     

                                                                

    Date

    


    



    
      
        


        CH1
          11133629.1

        
        

      

      
        10

        
          

        

      

      
        
        

      

    


    


    
      


      
        	
                  Amended
                  and Restated Schedule 2

              
	
                  to

              
	
                  Loan
                  and Security Agreement

              
	 
	 
	
                Borrower:

              	
                 North
                  American Scientific, Inc., a Delaware
                  Corporation

              
	 	
                 North
                  American Scientific, Inc., a California
                  Corporation

              
	 	
                 NOMOS
                  Corporation, a Delaware corporation

              
	 	 
	
                Date:

              	
                 October
                  31, 2006

              


      

      


      This
        Amended and Restated Schedule 2 amends and restates in its entirety the Amended
        and Restated Schedule 2 dated January 12, 2006 to the Loan and Security
        Agreement dated October 5, 2005 (as amended, the “Loan Agreement”) between
        Silicon Valley Bank (“Bank”) and the above-borrowers (collectively, jointly and
        severally, the “Borrower”), and forms an integral part of the same. (Capitalized
        terms used herein, which are not defined, shall have the meanings set forth
        in
        the Loan Agreement.)

      
        
          

        



      
        	
                1

              	
                .

              	
                CREDIT
                  LIMIT

              	 	 	 
	 	 	
                (Section
                  2.1.1):

              	
                 An
                  amount not to exceed:

              
	 	 	 	
                 (a)

              	
                 the
                  lesser of (1) $4,000,000
                  at
                  any one time outstanding

              
	 	 	 	 	
                 (the
                  “Revolving
                  Line Credit Amount”)
                  or (2) the sum

              
	 	 	 	 	
                 of
                  the following (the “Borrowing Base”):

              
	 	 	 	 	 
	 	 	 	 	
                 (i)

              	
                 up
                  to 80%
                  (an
                  “Advance Rate”) of the amount

              
	 	 	 	 	 	
                 of
                  NASI Eligible Accounts, plus

              
	 	 	 	 	
                 (ii)

              	
                 up
                  to 80%
                  (an
                  “Advance Rate”) of the amount

              
	 	 	 	 	 	
                 of
                  NASI-CA Eligible Accounts, plus

              
	 	 	 	 	
                 (iii)

              	
                 up
                  to 75%
                  (an
                  “Advance Rate”) of the amount

              
	 	 	 	 	 	
                 of
                  NOMOS Eligible Accounts;

              
	 	 	 	 	 	 
	 	 	
                minus

              	 	 	 
	 	 	
                (b)

              	
                 the
                  sum of the following:

              
	 	 	 	 	
                 (i)

              	
                 the
                  amount of all outstanding Letters of Credit

              
	 	 	 	 	 	
                 (including
                  drawn but unreimbursed Letters of

              
	 	 	 	 	 	
                 Credit);
                  plus

              
	 	 	 	 	
                 (ii)

              	
                 the
                  FX Reserve; and plus

              
	 	 	 	 	
                 (iii)

              	
                 the
                  aggregate amount of Cash Management

              
	 	 	 	 	 	
                 Services
                  utilizations.

              
	 	 	 	
                 provided,
                  however,
                  that Bank shall have the right, in Bank’s

              
	 	 	 	
                 discretion,
                  to modify the above Advance Rates based upon the

              
	 	 	 	
                 results
                  of field audits conducted by Bank.

              


      

      


      
        
          
          

        

        
          11

          
            

          

        

        
          
          

        

      

      


      
        	 	 	
                Letter
                  of Credit Sublimit

              	 
	 	 	
                (Section
                  2.1.2):

              	
                $500,000.

              
	 	 	
                Foreign
                  Exchange Sublimit

              	 
	 	 	
                (Section
                  2.1.3):

              	
                $500,000.

              
	 	 	
                Cash
                  Management Services Sublimit:

              	 
	 	 	
                (Section
                  2.1.4):

              	
                $500,000.

              
	 	 	 	 
	 	 	 	 
	
                2

              	
                .

              	
                INTEREST.

              	 
	 	 	
                   Interest
                  Rate

              	 
	 	 	
                  
(Section
                  2.3(a)):

              	 A
                per annum rate equal to the “Prime Rate” in effect from time
	 	 	 	 to
                time; provided that if the Quick Ratio Test is not met, the
	 	 	 	 interest
                rate applicable to the Obligations shall be a per annum
	 	 	 	 rate
                equal to the “Prime Rate” in effect from time to time, plus
	 	 	 	 1.50%
                per annum. Changes in the interest rate based on
	 	 	 	 whether
                or not the Quick Ratio Test is met shall go into effect
	 	 	 	 as
                of the first day of the month closest to the date Borrower’s
	 	 	 	 financial
                statements, which show whether or not the Quick
	 	 	 	 Ratio
                Test is met, are due, even if the delivery of the financial
	 	 	 	 statements
                is delayed.


      

      


      
        	
                3

              	
                .

              	
                FEES
                  (Section
                  2.4(a)):

              	 
	 	 	 	 
	 	 	
                   Facility
                  Fee:

              	
                $20,000
                  payable on the date hereof. If at any date the Quick

              
	 	 	 	
                Ratio
                  Test is not met, Borrower shall pay Bank an additional

              
	 	 	 	
                Facility
                  Fee of $20,000 on the date Bank receives financial

              
	 	 	 	
                statements
                  showing the Quick Ratio Test was not met.

              
	 	 	 	 
	 	 	
                   Collateral
                  Handling Fee:

              	
                None,
                  provided that if the Quick Ratio Test is not met,

              
	 	 	 	
                Borrower
                  shall pay Bank a collateral handling fee in an amount

              
	 	 	 	
                equal
                  to $2,000 per month, payable in arrears on the first
                  day

              
	 	 	 	
                of
                  each month with respect to the prior month. Changes in

              
	 	 	 	
                whether
                  or not the collateral handling fee is charged, based on

              
	 	 	 	
                whether
                  or not the Quick Ratio Test is met shall go into effect

              
	 	 	 	
                as
                  of the first day of the month closest to the date
                  Borrower’s

              
	 	 	 	
                financial
                  statements, which show whether or not the Quick

              
	 	 	 	
                Ratio
                  Test is met, are due, even if the delivery of the
                  financial

              
	 	 	 	
                statements
                  is delayed.

              
	 	 	 	 
	 	 	
                 Unused
                  Line Fee:

              	
                None,
                  provided that if the Quick Ratio Test is not met,

              
	 	 	 	
                Borrower
                  shall pay to Bank an unused line fee equal to the rate

              
	 	 	 	
                of
                  one-half of one percentage point (.50%) per annum

              
	 	 	 	 
	 	 	 	 


      

      


      


      
        
          
          

        

        
          12

          
            

          

        

        
          
          

        

      

      
        	 	
                 multiplied
                  by the amount by which the Revolving Line Credit

              
	 	
                 Amount
                  exceeds the average daily principal balance of the

              
	 	
                 outstanding
                  aggregate amount of the sum, without duplication,

              
	 	
                 of
                  Advances, Letters of Credit, FX Reserve and Cash

              
	 	
                 Management
                  Services utilizations during the immediately

              
	 	
                 preceding
                  calendar month (or part thereof), which fee shall be

              
	 	
                 payable
                  monthly in arrears on the first day of each month.

              
	 	
                 Changes
                  in whether or not the unusued line fee is charged,

              
	 	
                 based
                  on whether or not the Quick Ratio Test is met shall go

              
	 	
                 into
                  effect as of the first day of the month closest to the
                  date

              
	 	
                 Borrower’s
                  financial statements, which show whether or not

              
	 	
                 the
                  Quick Ratio Test is met, are due, even if the delivery of
                  the

              
	 	
                 financial
                  statements is delayed.

              
	 	 
	
                    Termination
                  Fee:

              	
                 The
                  "Termination
                  Fee"
                  that is payable as set forth in Section

              
	 	
                 2.1.1(d)
                  shall be equal to one percent (1%) of the Revolving

              
	 	
                 Line
                  Credit Amount in effect from time to time, providedthat

              
	 	
                 no
                  termination fee shall be charged if the credit facility

              
	 	
                 hereunder
                  is replaced with a new facility from another division

              
	 	
                 of
                  Bank.

              


      

      


          None
        of the
        fees provided for in this Agreement are refundable.

       

      
        
          

        



      
        	
                4

              	
                .

              	
                MATURITY

              	 	 	 
	 	 	
                DATE

              	 	 	 
	 	 	
                (Section
                  13.1):

              	 	
                October
                  3, 2007.

              	 
	 	 	 	 	 	 
	
                5

              	
                .

              	
                FINANCIAL
                  COVENANTS

              	 	 	 
	 	 	
                    (Section
                  6.7):

              	 	
                Borrower
                  shall comply with the following financial covenant

              	 
	 	 	 	 	
                at
                  all times during the term of this Agreement, measured at
                  the

              	 
	 	 	 	 	
                end
                  of each month, and, Borrower shall provide evidence of

              	 
	 	 	 	 	
                compliance
                  therewith to Bank monthly and otherwise at the

              	 
	 	 	 	 	
                request
                  of Bank from time to time.

              	 
	 	 	
                    Minimum
                  Tangible

              	 	 	 
	 	 	
                    Net
                  Worth:

              	 	
                Borrower
                  shall maintain a Tangible Net Worth of not less than

              	 
	 	 	 	
                 

              	
                
                  $5,000,000

                

              	
                .

              
	 	 	 	 	
                “Tangible
                  Net Worth” shall mean the excess of total assets less

              	 
	 	 	 	 	
                total
                  liabilities, determined in accordance with GAAP, with the

              	 
	 	 	 	 	
                following
                  adjustments:

              	 
	 	 	 	 	 	 
	 	 	 	 	
                    (A)
                  there shall be excluded from assets: (i) notes,

              	 
	 	 	 	 	
                    accounts
                  receivable and other obligations owing to

              	 
	 	 	 	 	
                    Borrower
                  from
                  its officers or other Affiliates, and (ii) all

              	 
	 	 	 	 	
                    assets
                  which would be classified as intangible assets under

              	 
	 	 	 	 	
                    GAAP,
                  including without limitation goodwill, licenses,

              	 
	 	 	 	 	
                    patents,
                  trademarks, trade names, copyrights, capitalized
                  software 

              	 
	 	 	 	 	
                    and organizational
                  costs, licenses and franchises, and (iii)
                  minority

              	 
	 	 	 	 	
                           
                  investments in other Persons.  

              	 
	
                 

              	
                 

              	
                 

              	
                 

              	
                    (B)
                  there shall
                  be excluded from liabilities: all indebtedness which
                  is  

              	 
	 	 	 	 	
                    subordinated
                  to
                  the Obligations under a subordination agreement in form 

              	 
	 	 	 	 	
                    specified
                  by
                  Bank or by language in the instrument evidencing the indebtedness
                  

              	 
	 	 	 	 	
                    which
                  Bank
                  agrees in writing is acceptable to Bank in its good faith business
                  judgment. 

              	 
	 	 	 	 	 	 


      

       

      Signatures
        on Next
        Page

       

      
        
          
          

        

        
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           IN
        WITNESS WHEREOF,
        the parties have executed this Amended and Restated Schedule 2 to Loan and
        Security Agreement as of the date first above written. 

      


      
        	
                “Borrower”:

              	
                 “Bank”:

              
	 	 
	
                 NORTH
                  AMERICAN SCIENTIFIC, INC.

              	
                 SILICON
                  VALLEY BANK

              
	
                 A
                  Delaware corporation

              	 
	 	 
	
                 By
                  /s/L.Michael
                  Cutrer

              	
                 By
                  /s/Kurt
                  Miklinski

              
	
                      
                  President
                  or Vice President

              	
                 Title
                  Vice
                  President

              


      

      


      NORTH
        AMERICAN SCIENTIFIC, INC.

      A
        California corporation 

       

      By/s/L.Michael
        Cutrer

      President
        or Vice President 

       

      NOMOS
        CORPORATION

       

      By 
        /s/L.Michael
        Cutrer

      President
        or Vice President

       

      
        
          
          

        

        
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