EXHIBIT
          4.3

      

       

      REGISTRATION
        RIGHTS AGREEMENT

       

      This
        Registration Rights Agreement (the
        "Agreement") is entered into as of the 30th
        day of June, 2005, by and among IsoRay
        Medical, Inc.,
        a Delaware corporation (the "Corporation"), Century
        Park Pictures Corporation,
        a Minnesota corporation (“Century Park”), and each of the Corporation's
        debenture holders and each of Century Park’s shareholders who is a signatory
        hereto (collectively, the "Signing Security Holders") .

       

      Recitals

       

      Whereas,
        the Corporation desires to raise between $2,000,000 and $4,000,000 in the
        form
        of convertible debentures to fund its working capital requirements.

       

      Whereas,
        the Corporation has agreed to provide certain demand and piggyback registration
        rights to the investors who purchase the convertible debentures placed by
        the
        placement agents to be retained by the Corporation or sold by officers of
        the
        Corporation. 

       

      Whereas,
        on
        May 27, 2005 the Corporation, Century Park and Century Park Transitory
        Subsidiary, Inc. entered into a merger agreement (the “Agreement”), which, if
        consummated, would result in the Corporation’s debentures being convertible into
        shares of common stock of Century Park. 

       

      Whereas,
        it
        is a condition to the merger (the “Merger”) contemplated by the Agreement that
        certain shareholders of Century Park be granted certain demand and piggyback
        registration rights by the post-merger surviving company. 

       

      Now,
        Therefore, in
        consideration of the foregoing and the mutual promises contained herein,
        and for
        other good and valuable consideration, the receipt and sufficiency of which
        are
        hereby acknowledged, the parties hereto agree as follows:

       

      SECTION
        1.  GENERAL.

       

      1.1  Definitions.
        As
        used in this Agreement, the following terms shall have the following respective
        meanings:

       

      "Board"
        shall mean the board of directors of the Company. 

       

      “Century
        Park Shares” shall mean those certain shares of Century Park’s common stock held
        by the signatories hereto that are shareholders of Century Park. 

       

      "Common
        Stock" or "Shares" shall mean the Company's Common Stock, or any other class
        of
        stock exchanged for Common Stock of the Company. 

       

      “Company”
        shall mean the Corporation prior to the closing of the Merger, and Century
        Park
        following the closing of the Merger. 

       

      
        
           

        

        
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      "Conversion
        Shares" shall mean those certain shares of Common Stock issued upon conversion
        of the convertible debentures placed by the placement agents to be retained
        by
        the Corporation or sold by officers of the Corporation. 

       

      “Debenture
        Holders” means these persons holding the Corporation’s convertible debentures
        who are signatories to this Agreement. 

       

      "Exchange
        Act" means the Securities Exchange Act of 1934, as amended.

       

      "GAAP"
        shall mean those generally accepted accounting principles and practices which
        are recognized by the American Institute of Certified Public Accountants
        and
        which are consistently applied for all periods so as to properly reflect
        the
        financial condition, and the results of operations and changes in financial
        position, of the Company.

       

      "Holder"
        means any person or entity owning of record Registrable Securities that have
        not
        been sold to the public or any assignee of record of such Registrable Securities
        in accordance with Section 2.7 hereof.

       

      "Register,"
        "registered," and "registration" refer to a registration effected by preparing
        and filing a registration statement in compliance with the Securities Act,
        and
        the declaration or ordering of effectiveness of such registration statement
        or
        document.

       

      "Registrable
        Securities" means (a) the Conversion Shares; (b) the Century Park
        Shares
        (solely if the Merger is consummated); and (c) any Common Stock of the
        Corporation or, if the Merger is consummated, of Century Park, issued as
        (or
        issuable upon the conversion or exercise of any warrant, right or other security
        which is issued as) a dividend or other distribution with respect to, or
        in
        exchange for or in replacement of, such above-described securities.
        Notwithstanding the foregoing, Registrable Securities shall not include any
        securities sold by a person or entity to the public either pursuant to a
        registration statement or Rule 144 or sold in a private transaction
        in
        which the transferor's rights under Section 2 of this Agreement are
        not
        assigned.

       

      "Registrable
        Securities then outstanding" shall be the number of shares determined by
        calculating the total number of shares of Common Stock that are Registrable
        Securities and either (a) are then issued and outstanding or (b) are
        issuable pursuant to then exercisable or convertible securities.

       

      "Registration
        Expenses" shall mean all expenses incurred by the Company in complying with
        Sections 2.1 and 2.2 hereof, including, without limitation, all
        registration and filing fees, printing expenses, fees and disbursements of
        counsel for the Company, reasonable fees and disbursements of special counsel
        for the Holders, blue sky fees and expenses and the expense of any special
        audits incident to or required by any such registration (but excluding the
        compensation of regular employees of the Company which shall be paid in any
        event by the Company).

       

      "SEC"
        or "Commission" means the Securities and Exchange Commission.

       

      "Securities
        Act" shall mean the Securities Act of 1933, as amended.

       

      
        
           

        

        
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      "Selling
        Expenses" shall mean all underwriting discounts and selling commissions
        applicable to the sale of the Company's capital stock.

       

      "Shareholders"
        shall mean all of the holders of the Company’s capital stock.

       

      "Special
        Registration Statement" shall mean a registration statement relating to any
        employee benefit plan or with respect to any corporate reorganization or
        other
        transaction under Rule 145 of the Securities Act.

       

      "Termination
        Date" shall mean twenty-four (24) months after the conclusion of the “Offering
        Period,” as such term is defined in the Corporation’s Confidential Private
        Placement Memorandum dated January 31, 2005, as amended and restated on May
        27,
        2005. 

       

      SECTION
        2.  PIGGYBACK
        REGISTRATION.

       

      2.1  Piggyback
        Registration.  The
        Company shall promptly notify all Holders of Registrable Securities in writing
        of any proposed filing of any registration statement under the Securities
        Act
        for purposes of a public offering of securities of the Company (including,
        but
        not limited to, registration statements relating to secondary offerings of
        securities of the Company, but excluding Special Registration Statements),
        which
        notice shall be made at least forty-five (45) days prior to such filing,
        and
        will afford each such Holder an opportunity to include in such registration
        statement all or part of the Registrable Securities held by such Holder.
        Each
        Holder desiring to include in any such registration statement all or any
        part of
        the Registrable Securities held by it shall, within twenty (20) days after
        receipt of the above-described notice from the Company, so notify the Company
        in
        writing. Such notice shall state the intended method of disposition of the
        Registrable Securities by such Holder. If a Holder decides not to include
        all of
        its Registrable Securities in any registration statement thereafter filed
        by the
        Company, such Holder shall forfeit all future right to include any Registrable
        Securities in any subsequent registration statement or registration statements
        as may be filed by the Company with respect to offerings of its securities.
        

       

      (a)  Underwriting.  If
        the registration statement under which the Company gives notice under this
        Section 2.1 is for an underwritten offering, the Company shall so
        advise
        the Holders of Registrable Securities. In such event, the right of any such
        Holder to be included in a registration pursuant to this Section 2.1
        shall
        be conditioned upon such Holder's participation in such underwriting and
        the
        inclusion of such Holder's Registrable Securities in the underwriting to
        the
        extent provided herein. All Holders proposing to distribute their Registrable
        Securities through such underwriting shall enter into an underwriting agreement
        in customary form with the underwriter or underwriters selected for such
        underwriting by the Company. Notwithstanding any other provision of this
        Agreement, if the underwriter determines in good faith that marketing factors
        require a limitation of the number of shares to be underwritten, the number
        of
        shares that may be included in the underwriting shall be allocated, first,
        to
        the Company; and second, to the Holders; and thereafter to any other
        Shareholders of the Company holding registration rights. If any Holder
        disapproves of the terms of any such underwriting, such Holder may elect
        to
        withdraw therefrom by written notice to the Company and the underwriter,
        delivered on or before the later of (i) five (5) business days after
        the
        receipt by all Holders of the underwriting agreement containing the terms
        thereof and (ii) ten (10) business days prior to the effective date
        of the
        registration statement. Any Registrable Securities excluded or withdrawn
        from
        such underwriting shall be excluded and withdrawn from the registration.
        For any
        Holder which is a partnership, limited liability company or corporation,
        the
        partners, retired partners, managers, members and shareholders of such Holder,
        or the estates and family members of any such partners and retired partners
        and
        any trusts for the benefit of any of the foregoing shall be deemed to be
        a
        single "Holder," and any pro
        rata
        reduction with respect to such "Holder" shall be based upon the aggregate
        amount
        of shares of Company capital stock carrying registration rights owned by
        all
        entities and individuals included in such “Holder,” as defined in this
        sentence.

       

      
        
           

        

        
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      (b)  Right
        to Terminate Registration. The
        Company shall have the right to terminate or withdraw any registration initiated
        by it under this Section 2.1 prior to the effectiveness of such
        registration whether or not any Holder has elected to include securities
        in such
        registration. The Registration Expenses of such withdrawn registration shall
        be
        borne by the Company in accordance with Section 2.3 hereof. 

       

      2.2  Demand
        Registration. At
        any time on or before November 1, 2005, Holders
        shall have a "onetime" demand right to make a written request ("Demand Request")
        that the Company register the Registrable Securities, provided that if the
        Merger is not consummated by August 1, 2005, all demand rights will be forfeited
        by all Holders. Within thirty (30) days after receipt of Demand Requests
        from
        Holders of at least a majority of the Registrable Securities, the Company
        shall
        prepare and file under the Act, one registration statement to permit a public
        offering of all of the Registrable Securities which shall include all Conversion
        Shares, including those issuable to Debenture Holders ("Demand Registration").
        Notwithstanding the rights granted in this Section 2.2, if a Debenture Holder
        has not elected to convert all or any part of his debentures on or before
        December 31, 2005 (by delivering the conversion form to the Company via
        facsimile by that date or mailing the conversion form to the Company with
        a
        postmark by that date), then the demand right granted by this Section 2.2
        shall
        be forfeited in full regardless of whether Conversion Shares have been included
        in the Demand Registration. 

       

      2.3  Expenses
        of Registration.  Except
        as specifically provided herein, all Registration Expenses incurred in
        connection with any registration pursuant to Sections 2.1 and 2.2 herein
        shall
        be borne by the Company. All Selling Expenses incurred in connection with
        any
        registrations hereunder shall be borne by the holders of the securities so
        registered pro
        rata
        on the basis of the number of Shares so registered. 

       

      2.4  Obligations
        of the Company.  Whenever
        required to effect the registration of any Registrable Securities, the Company
        shall, as expeditiously as reasonably possible (and, with respect to any
        registration statement required to be filed pursuant to Section 2.2, in any
        event within thirty (30) days): 

       

      (a)  With
        respect to any registration statement required to be filed under
        Section 2.2, prepare and file with the SEC a registration statement
        with
        respect to such Registrable Securities and use all reasonable efforts to
        cause
        such registration statement to become effective, and, upon the request of
        the
        Holders of a majority of the Registrable Securities registered thereunder,
        keep
        such registration statement effective for up to two (2) years or, if earlier,
        until the Holders have completed the distribution related thereto.

       

      
        
           

        

        
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      (b)  Prepare
        and file with the SEC such amendments and supplements to such registration
        statement and the prospectus used in connection with such registration statement
        as may be necessary to comply with the provisions of the Securities Act with
        respect to the disposition of all securities covered by such registration
        statement for the period set forth in paragraph (a) above.

       

      (c)  Furnish
        to the Holders such number of copies of a prospectus, including a preliminary
        prospectus, in conformity with the requirements of the Securities Act, and
        such
        other documents as they may reasonably request in order to facilitate the
        disposition of Registrable Securities owned by them.

       

      (d)  Use
        its reasonable efforts to register and qualify the securities covered by
        such
        registration statement under such other securities or Blue Sky laws of such
        jurisdictions as shall be reasonably requested by the Holders; provided
        that
        the Company shall not be required in connection therewith or as a condition
        thereto to qualify to do business or to file a general consent to service
        of
        process in any such states or jurisdictions.

       

      (e)  In
        the event of any underwritten public offering, enter into and perform its
        obligations under an underwriting agreement, in usual and customary form,
        with
        the managing underwriter(s) of such offering. Each Holder participating in
        such
        underwriting shall also enter into and perform its obligations under such
        an
        agreement.

       

      (f)  Notify
        each Holder of Registrable Securities covered by such registration statement
        at
        any time when a prospectus relating thereto is required to be delivered under
        the Securities Act of the happening of any event as a result of which the
        prospectus included in such registration statement, as then in effect, includes
        an untrue statement of a material fact or omits to state a material fact
        required to be stated therein or necessary to make the statements therein
        not
        misleading in the light of the circumstances then existing. The Company will
        use
        reasonable efforts to amend or supplement such prospectus in order to cause
        such
        prospectus not to include any untrue statement of a material fact or omit
        to
        state a material fact required to be stated therein or necessary to make
        the
        statements therein not misleading in the light of the circumstances then
        existing.

       

      (g)  Use
        its reasonable efforts to furnish, on the date that such Registrable Securities
        are delivered to the underwriters for sale, if such securities are being
        sold
        through underwriters, (i) an opinion, dated as of such date, of the
        counsel
        representing the Company for the purposes of such registration, in form and
        substance as is customarily given to underwriters in an underwritten public
        offering, addressed to the underwriters, if any, and (ii) a letter
        dated as
        of such date, from the independent certified public accountants of the Company,
        in form and substance as is customarily given by independent certified public
        accountants to underwriters in an underwritten public offering addressed
        to the
        underwriters.

       

      
        
           

        

        
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      2.5  Furnishing
        Information.  It
        shall
        be a condition precedent to the obligations of the Company to take any action
        pursuant to Sections 2.1 and 2.2 that the selling Holders shall furnish
        to
        the Company such information regarding themselves and warrant the accuracy
        thereof, the Registrable Securities held by them and the intended method
        of
        disposition of such securities as shall be required to effect the registration
        of their Registrable Securities.

       

      2.6  Indemnification.  In
        the event any Registrable Securities are included in a registration statement
        under Sections 2.1 and 2.2:

       

      (a)  To
        the extent permitted by law, the Company will indemnify and hold harmless
        each
        Holder, the partners, officers and directors of each Holder, any underwriter
        (as
        defined in the Securities Act) for such Holder and each person, if any, who
        controls such Holder or underwriter within the meaning of the Securities
        Act or
        the Exchange Act, against any losses, claims, damages, or liabilities (joint
        or
        several) to which they may become subject under the Securities Act, the Exchange
        Act or other federal or state law, insofar as such losses, claims, damages
        or
        liabilities (or actions in respect thereof) arise out of or are based upon
        any
        of the following statements, omissions or violations (collectively a
        "Violation") by the Company: (i) any untrue statement or alleged untrue
        statement of a material fact contained in such registration statement, including
        any preliminary prospectus or final prospectus contained therein or any
        amendments or supplements thereto, (ii) the omission or alleged omission
        to
        state therein a material fact required to be stated therein, or necessary
        to
        make the statements therein not misleading, or (iii) any violation
        or
        alleged violation by the Company of the Securities Act, the Exchange Act,
        any
        state securities law or any rule or regulation promulgated under the Securities
        Act, the Exchange Act or any state securities law in connection with the
        offering covered by such registration statement; and the Company will pay
        as
        incurred to each such Holder, partner, officer, director, underwriter or
        controlling person for any legal or other expenses reasonably incurred by
        them
        in connection with investigating or defending any such loss, claim, damage,
        liability or action; provided
        however,
        that the indemnity agreement contained in this Section 2.6(a) shall
        not
        apply to amounts paid in settlement of any such loss, claim, damage, liability
        or action if such settlement is effected without the consent of the Company,
        which consent shall not be unreasonably withheld, nor shall the Company be
        liable in any such case for any such loss, claim, damage, liability or action
        to
        the extent that it arises out of or is based upon a Violation which occurs
        in
        reliance upon and in conformity with written information furnished expressly
        for
        use in connection with such registration by such Holder, partner, officer,
        director, underwriter or controlling person of such Holder.

       

      (b)  To
        the extent permitted by law, each Holder will, if Registrable Securities
        held by
        such Holder are included in the securities as to which such registration
        qualifications or compliance is being effected, indemnify and hold harmless
        the
        Company, each of its directors, its officers and each person, if any, who
        controls the Company within the meaning of the Securities Act, any underwriter
        and any other Holder selling securities under such registration statement
        or any
        of such other Holder's partners, directors or officers or any person who
        controls such Holder, against any losses, claims, damages or liabilities
        (joint
        or several) to which the Company or any such director, officer, controlling
        person, underwriter or other such Holder, or partner, director, officer or
        controlling person of such other Holder may become subject under the Securities
        Act, the Exchange Act or other federal or state law, insofar as such losses,
        claims, damages or liabilities (or actions in respect thereto) arise out
        of or
        are based upon any Violation, in each case to the extent (and only to the
        extent) that such Violation occurs in reliance upon and in conformity with
        written information furnished by such Holder under an instrument duly executed
        by such Holder and stated to be specifically for use in connection with such
        registration; and each such Holder will pay as incurred any legal or other
        expenses reasonably incurred by the Company or any such director, officer,
        controlling person, underwriter or other Holder, or partner, officer, director
        or controlling person of such other Holder in connection with investigating
        or
        defending any such loss, claim, damage, liability or action if it is judicially
        determined that there was such a Violation; provided,
        however,
        that the indemnity agreement contained in this Section 2.6(b) shall
        not
        apply to amounts paid in settlement of any such loss, claim, damage, liability
        or action if such settlement is effected without the consent of the Holder,
        which consent shall not be unreasonably withheld; provided
        further,
        that in no event shall any indemnity under this Section 2.6 exceed
        the net
        proceeds from the offering received by such Holder.

       

      
        
           

        

        
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      (c)  Promptly
        after receipt by an indemnified party under this Section 2.6 of notice
        of
        the commencement of any action (including any governmental action), such
        indemnified party will, if a claim in respect thereof is to be made against
        any
        indemnifying party under this Section 2.6, deliver to the indemnifying
        party a written notice of the commencement thereof and the indemnifying party
        shall have the right to participate in, and, to the extent the indemnifying
        party so desires, jointly with any other indemnifying party similarly noticed,
        to assume the defense thereof with counsel mutually satisfactory to the parties;
        provided,
        however,
        that an indemnified party shall have the right to retain its own counsel,
        with
        the fees and expenses to be paid by the indemnifying party, if representation
        of
        such indemnified party by the counsel retained by the indemnifying party
        would
        be inappropriate due to actual or potential differing interests between such
        indemnified party and any other party represented by such counsel in such
        proceeding. The failure to deliver written notice to the indemnifying party
        within a reasonable time of the commencement of any such action, if materially
        prejudicial to its ability to defend such action, shall relieve such
        indemnifying party of any liability to the indemnified party under this
        Section 2.6, but the omission so to deliver written notice to the
        indemnifying party will not relieve it of any liability that it may have
        to any
        indemnified party otherwise than under this Section 2.6.

       

      (d)  If
        the indemnification provided for in this Section 2.6 is held by a
        court of
        competent jurisdiction to be unavailable to an indemnified party with respect
        to
        any losses, claims, damages or liabilities referred to herein, the indemnifying
        party, in lieu of indemnifying such indemnified party thereunder, shall to
        the
        extent permitted by applicable law contribute to the amount paid or payable
        by
        such indemnified party as a result of such loss, claim, damage or liability
        in
        such proportion as is appropriate to reflect the relative fault of the
        indemnifying party on the one hand and of the indemnified party on the other
        in
        connection with the Violation(s) that resulted in such loss, claim, damage
        or
        liability, as well as any other relevant equitable considerations. The relative
        fault of the indemnifying party and of the indemnified party shall be determined
        by a court of law by reference to, among other things, whether the untrue
        or
        alleged untrue statement of a material fact or the omission to state a material
        fact relates to information supplied by the indemnifying party or by the
        indemnified party and the parties' relative intent, knowledge, access to
        information and opportunity to correct or prevent such statement or omission;
        provided,
        that in no event shall any contribution by a Holder hereunder exceed the
        net
        proceeds from the offering received by such Holder.

       

      (e)  The
        obligations of the Company and Holders under this Section 2.6 shall
        survive
        completion of any offering of Registrable Securities in a registration statement
        and the termination of this agreement. No Indemnifying Party, in the defense
        of
        any such claim or litigation, shall, except with the consent of each Indemnified
        Party, consent to entry of any judgment or enter into any settlement which
        does
        not include as an unconditional term thereof the giving by the claimant or
        plaintiff to such Indemnified Party of a release from all liability in respect
        to such claim or litigation.

       

      
        
           

        

        
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      2.7  Assignment
        of Registration Rights.  The
        registration rights of the Holders under this Agreement may be transferred
        to
        any transferee if the Company is given written notice by the Holder at the
        time
        of such transfer stating the name and address of the transferee and identifying
        the securities with respect to which the rights under this Agreement are
        being
        assigned.

       

      2.8  Amendment
        of Registration Rights.  Any
        provision of this Section 2 may be amended and the observance thereof
        may
        be waived (either generally or in a particular instance and either retroactively
        or prospectively), only with the written consent of the Company and the Holders
        of at least a majority of the Registrable Securities then outstanding. Any
        amendment or waiver effected in accordance with this Section 2.8 shall
        be
        binding upon each Holder and the Company. By acceptance of any benefits under
        this Section 2, Holders of Registrable Securities hereby agree to
        be bound
        by the provisions hereunder.

       

      2.9  Rule
        144 Reporting.  With
        a view to making available to the Holders the benefits of certain rules and
        regulations of the SEC which may permit the sale of the Registrable Securities
        to the public without registration, the Company agrees to use its best efforts
        to:

       

      (a)  Make
        and keep public information available, as those terms are understood and
        defined
        in SEC Rule 144 or any similar or analogous rule promulgated under
        the
        Securities Act, at all times after the effective date of the first registration
        filed by the Company for an offering of its securities to the general
        public;

       

      (b)  File
        with the SEC, in a timely manner, all reports and other documents required
        of
        the Company under the Exchange Act; and

       

      (c)  So
        long as a Holder owns any Registrable Securities, furnish to such Holder
        forthwith upon request: a written statement by the Company as to its compliance
        with the reporting requirements of said Rule 144 of the Securities Act, and
        of
        the Exchange Act (at any time after it has become subject to such reporting
        requirements); a copy of the most recent annual or quarterly report of the
        Company; and such other reports and documents as a Holder may reasonably
        request
        in availing itself of any rule or regulation of the SEC allowing it to sell
        any
        such securities without registration.

       

      
        
           

        

        
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      SECTION
        3.  MISCELLANEOUS.

       

      3.1  Governing
        Law.  This
        Agreement and
        the
        rights and obligations of the parties hereto, shall be governed, construed
        and
        interpreted according to the laws of the State of Delaware. The parties agree
        that any final judgment after exhaustion of all appeals or the expiration
        of
        time to appeal in any such action or proceeding shall be conclusive and binding,
        and may be enforced in any federal or state court in the United States by
        suit
        on the judgment or in any other manner provided by law. Nothing contained
        in
        this Agreement shall affect or limit the right of a party to serve any process
        or notice or motion or other application in any other manner permitted by
        law,
        or limit or affect the right of a party to bring any action or proceeding
        against the other parties or any of their respective property in the courts
        of
        any other jurisdiction. All parties hereby consent to the jurisdiction of
        the
        federal courts whose districts encompass any part of the city of Phoenix
        or the
        state courts of the state of Arizona sitting in the city of Phoenix in
        connection with any dispute arising under this Agreement, and hereby waive,
        to
        the maximum extent permitted by law, any objection, including any objections
        based on forum non
        conveniens, to
        the
        bringing of any such proceeding in such jurisdictions.

       

      3.2  Successors
        and Assigns.  Except
        as otherwise expressly provided herein, the provisions hereof shall inure
        to the
        benefit of, and be binding upon, the successors, assigns, heirs, executors,
        and
        administrators of the parties hereto and shall inure to the benefit of and
        be
        enforceable by each person who shall be a Holder of Registrable Securities
        or
        any successor to any of the Signing Security Holder’s respective rights
        hereunder, from time to time; provided,
        however,
        that prior to the receipt by the Company of adequate written notice of the
        transfer of any Registrable Securities or any rights hereunder specifying
        the
        full name and address of the transferee, the Company may deem and treat the
        person listed as the Holder of such shares in its records as the absolute
        owner
        and Holder of such shares for all purposes, including the payment of dividends
        or any redemption price.

       

      3.3  Severability.  In
        the event one or more of the provisions of this Agreement should, for any
        reason, be held to be invalid, illegal or unenforceable in any respect, such
        invalidity, illegality, or unenforceability shall not affect any other
        provisions of this Agreement, and this Agreement shall be construed as if
        such
        invalid, illegal or unenforceable provision had never been contained
        herein.

       

      3.4  Amendment
        and Waiver.

       

      (a)  Except
        as otherwise expressly provided, this Agreement may be amended or modified
        only
        upon the written consent of the Company and the Holders of at least a majority
        of the Registrable Securities.

       

      (b)  Except
        as otherwise expressly provided herein, the obligations of the Company and
        the
        rights of the Holders under this Agreement may be waived only with the written
        consent of the Holders of at least a majority of the Registrable
        Securities.

       

      
        
           

        

        
          9

          
            

          

        

        
           

        

         

      

      3.5  Delays
        or Omissions.  It
        is agreed that no delay or omission to exercise any right, power, or remedy
        accruing to any Holder, upon any breach, default or noncompliance of the
        Company
        under this Agreement shall impair any such right, power, or remedy, nor shall
        it
        be construed to be a waiver of any such breach, default or noncompliance,
        or any
        acquiescence therein, or of any similar breach, default or noncompliance
        thereafter occurring. It is further agreed that any waiver, permit, consent,
        or
        approval of any kind or character on any Holder's part of any breach, default
        or
        noncompliance under the Agreement or any waiver on such Holder's part of
        any
        provisions or conditions of this Agreement must be in writing and shall be
        effective only to the extent specifically set forth in such writing. All
        remedies, either under this Agreement, by law, or otherwise afforded to Holders,
        shall be cumulative and not alternative.

       

      3.6  Notices.
        All
        notices required or permitted hereunder shall be in writing and shall be
        deemed
        effectively given: (a) upon personal delivery to the party to be notified,
        (b) three (3) days after having been sent by registered or certified
        mail,
        return receipt requested, postage prepaid, or (c) one (1) day after
        deposit
        with a nationally recognized overnight courier, specifying next day delivery,
        with written verification of receipt. All communications shall be sent to
        the
        party to be notified at the address as set forth on either the signature
        pages
        hereof or at such other address as such party may designate by ten (10) days
        advance written notice to the other parties hereto. 

       

      3.7  Attorneys'
        Fees.  In
        the event that any suit or action is instituted to enforce any provision
        in this
        Agreement, the prevailing party in such dispute shall be entitled to recover
        from the losing party all fees, costs and expenses of enforcing any right
        of
        such prevailing party under or with respect to this Agreement, including
        without
        limitation, such reasonable fees and expenses of attorneys and accountants,
        which shall include, without limitation, all fees, costs and expenses of
        appeals.

       

      3.8  Construction.
        The
        terms of this Agreement constitute the written expression of the mutual
        agreement of the parties and shall be construed neutrally and not for or
        against
        either party. Whenever a noun or pronoun is used in this Agreement in the
        singular and when required by the context, the same shall include the plural,
        and the masculine gender shall include the feminine and neuter genders and
        vice
        versa. As used in this Agreement, the term "party" or "parties" shall mean
        the
        parties to this Agreement. The term "person" shall include any individual,
        entity, trust or association. The headings in this Agreement are inserted
        for
        convenience; the provisions of this Agreement shall control in determining
        the
        intent hereof.

       

      3.9  Enforcement;
        Specific Performance; Remedies Cumulative. 

       

      (a)  In
        case
        any one or more defaults shall occur and be continuing, a party may proceed
        to
        protect and enforce its rights by an action at law, suit in equity or other
        appropriate proceeding, whether for the specific performance of any agreement
        contained herein or for an injunction against a violation of any of the terms
        hereof or thereof, or in aid of the exercise of any power granted hereby
        or
        thereby or by law.

       

      (b)  The
        parties expressly agree that each party may not have adequate remedies at
        law if
        the other parties do not perform its obligations under this Agreement. Upon
        a
        party's breach of the terms or covenants of this Agreement, the other parties
        shall, each in addition to all other remedies, be entitled to obtain injunctive
        relief, and an order for specific performance of the breaching party's
        obligations hereunder. 

       

      
        
           

        

        
          10

          
            

          

        

        
           

        

         

      

      3.10  Other
        Registration Rights.
        Each
        signing Security Holder understands and acknowledges that certain shareholders
        of the Corporation who purchased common stock at $2.00 per share as part
        of the
        Corporation’s private offering in the Fall of 2004 have piggyback registration
        rights that will be triggered by the Holders’ exercise of their demand right
        pursuant to this Agreement. 

       

      3.11  Counterparts.
        This
        Agreement may be executed in any number of counterparts, each of which shall
        be
        an original, but all of which together shall constitute one
        instrument.

       

      [Signature
        page to follow]

       


      
        
           

        

        
          11

          
            

          

        

        
           

        

      


      In
        Witness Whereof, the
        parties hereto have executed this Registration
        Rights Agreement as
        of the date set forth in the first paragraph hereof.

       

      
        	
                Isoray
                  Medical, Inc 

                 

                By:
                  ___________________________

                Name: Roger
                  Girard

                Title: CEO

                 

              	
                Century
                  Park Pictures Corporation

                 

                By:
                  ___________________________

                Name:
                  Thomas
                  Scallen

                Title:
                  CEO

              
	
                Address:   
                  350
                  Hills Street, 

                Suite
                  106

                Richland,
                  WA 99354

              	
                Address:  
                     4701
                  IDS Center

                Minneapolis,
                  MN 55402

                 

              
	 	 
	
                Security
                  holders

                 

                 

                By:__________________________ 

                Name:
                  

                Address:__________________________

                       
                          __________________________

                 

                By:__________________________

                Name:
                  

                Address:__________________________

                        __________________________

                 

                By:__________________________

                Name:
                  

                Address:__________________________

                        __________________________

                 

                By:__________________________

                Name:
                  

                Address:__________________________

                        __________________________

                 

                 

                By:__________________________

                Name:
                  

                Address:__________________________

                        __________________________

              	
                Security
                  holders

                 

                 

                By:__________________________ 

                Name:
                  

                Address:__________________________

                        __________________________

                 

                By: 

                Name:
                  

                Address:__________________________

                        __________________________

                 

                By:__________________________

                Name:
                  

                Address:__________________________

                        __________________________

                 

                By:__________________________

                Name:
                  

                Address:__________________________

                        __________________________

                 

                 

                By:__________________________

                Name:
                  

                Address:__________________________

                        __________________________

                 

              


      

      


      
        
           

        

        
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