ELEVENTH
      AMENDMENT
      

    TO
      

    LOAN
      AND SECURITY AGREEMENT

    


    THIS
      ELEVENTH
      AMENDMENT to
      Loan and Security Agreement
      (this “Amendment”)
      is entered into on October 10, 2008, 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”); and

     

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

    


     

    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”). 

     

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

     

    C. Borrower
      has requested that Bank amend the Loan Agreement, as herein set forth, and
      Bank
      has agreed to the same, but only to the extent, in accordance with the terms,
      subject to the conditions and in reliance upon the representations and
      warranties set forth herein.

     

    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 as of the date
      hereof:

     

    2.1 Modified
      Definition of Eligible Accounts.
      Subclause (a) of the definition of Eligible Accounts, which describes certain
      Accounts that are not included in the definition of Eligible Accounts, as set
      forth in Section 13.1 of the Loan Agreement is hereby amended to read as
      follows:

     

    
      
         

      

      
        1

        
          

        

      

      
         

      

    

    (a) Accounts
      that the account debtor has not paid within 90 days of invoice date;
provided,
      however,
      that
      with respect to the following account debtors, Accounts that the account debtor
      has not paid within 150 days of invoice date (the “Extended Terms Accounts”):
      (i) Premier Brachytherapy, (ii) Richmond University, (iii) MPM Medical Products,
      (iv) Bahman Daneshfar MD, (v) Piedmont Prostate Center, (vi) California Pacific
      Medical Center, (vii) Rochester General Hospital, (viii) Bellevue Urology
      Associates, (ix) Prologics and (x) Servicios De Radioterapia Oncologica,
provided
      that the
      aggregate amount of such Extended Term Accounts shall not exceed $300,000 at
      any
      one time outstanding for all such account debtors combined and provided,
      further,
      that
      Borrower shall deliver to Bank as soon as available, but no later than 30 days
      after the end of each month, a report showing the Extended Term Accounts, by
      account debtor, the amounts outstanding with respect thereto, the days
      outstanding of such Extended Term Accounts and such other information as Bank
      may require. 

     

    2.2 Modified
      Disbursement of Growth Capital Loan. Paragraph
      2 of Section 1 of the Amended and Restated Schedule 2 to Loan and Security
      Agreement that currently reads as follows:

     

    2. Growth
      Capital Loan.
      An
      amount equal to the unpaid principal balance from time to time outstanding
      of
      the Loan (the “Growth
      Capital Loan”)
      in the
      original principal amount of up to $3,000,000
      to be
      disbursed as follows: (i) $1,500,000 disbursed concurrently herewith and (ii)
      up
      to $1,500,000 to be disbursed prior to September 30, 2008. The Growth Capital
      Loan may be used for working capital purposes of Borrower. Once any portion
      of
      the Growth Capital Loan is repaid, it cannot be reborrowed.

    


    is
      hereby
      amended to read as follows:

     

    2. Growth
      Capital Loan.
      An
      amount equal to the unpaid principal balance from time to time outstanding
      of
      the Loan (the “Growth
      Capital Loan”)
      in the
      original principal amount of up to $3,000,000
      to be
      disbursed as follows: (i) $1,500,000 disbursed on May 28, 2008 and (ii) up
      to
      $1,500,000 to be disbursed prior to March 31, 2009; provided
      that any
      disbursement made pursuant to subclause (ii) above shall only be made after
      Borrower provides Bank evidence, satisfactory to Bank in its good faith business
      judgment, that Borrower has completed nine (9) additional in-patient trials
      with
      respect to Borrower’s ClearPath product which trials must be completed on or
      after October 8, 2008. The Growth Capital Loan may be used for working capital
      purposes of Borrower. Once any portion of the Growth Capital Loan is repaid,
      it
      cannot be reborrowed.

     

    
      
         

      

      
        2

        
          

        

      

      
         

      

    

     

    2.3 Modified
      Repayment of Growth Capital Loan. That
      portion of Section 4 of the Amended and Restated Schedule 2 to the Loan and
      Security Agreement that currently reads as follows:

     

    Notwithstanding
      the foregoing, with respect to the Growth Capital Loan: The outstanding
      principal balance of the Growth Capital Loan shall be repaid by Borrower to
      Silicon in thirty-six (36) equal monthly payments of principal, commencing
      on
      October 1, 2008 and continuing on the first day of each subsequent month until
      the earlier of the following dates: (i) September 1, 2011, or (ii) the date
      the
      Growth Capital Loan has been indefeasibly paid in full, or (iii) the date this
      Agreement terminates by its terms or is terminated by either party in accordance
      with its terms. On the earlier to occur of the foregoing dates, the entire
      unpaid principal balance of the Growth Capital Loan, plus all accrued and unpaid
      interest thereon, shall be due and payable. Interest on the Growth Capital
      Loan
      shall be payable monthly (regardless of whether any principal payment is to
      be
      made in such month) as provided in Section 2.3 of this Agreement.

     

    is
      hereby
      amended to read as follows:

     

    Notwithstanding
      the foregoing, with respect to the Growth Capital Loan: The outstanding
      principal balance of the Growth Capital Loan shall be repaid by Borrower to
      Silicon in thirty-three (33) equal monthly payments of principal, commencing
      on
      January 1, 2009 and continuing on the first day of each subsequent month until
      the earlier of the following dates: (i) September 1, 2011, or (ii) the date
      the
      Growth Capital Loan has been indefeasibly paid in full, or (iii) the date this
      Agreement terminates by its terms or is terminated by either party in accordance
      with its terms. On the earlier to occur of the foregoing dates, the entire
      unpaid principal balance of the Growth Capital Loan, plus all accrued and unpaid
      interest thereon, shall be due and payable. Interest on the Growth Capital
      Loan
      shall be payable monthly (regardless of whether any principal payment is to
      be
      made in such month) as provided in Section 2.3 of this Agreement. 

     

    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

        
          

        

      

      
         

      

    

    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 NASI-DE delivered to Bank on the Effective Date
      remain accurate and complete and have not been amended, supplemented or restated
      since the Effective Date (except pursuant to those certain Amendments to
      Certificate of Incorporation filed with the Delaware Secretary of State on
      April
      20, 2007, January 17, 2008 and April 30, 2008) and are, and continue to be,
      in
      full force and effect. The organizational documents of NASI-CA 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; 

     

    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

        
          

        

      

      
         

      

    

    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.

     

    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 (a) the due execution and delivery
      to
      Bank of this Amendment by each party hereto and (b) Borrower’s payment of an
      amendment fee in an amount equal to $15,000. 

     

    [Signature
      page follows.]

    


    
      
         

      

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

    


    
      	“Borrower”:	 	“Bank”:
	 	 	 
	 	 	 
	
              NORTH
                AMERICAN SCIENTIFIC, INC.
A
                Delaware corporation

            	 	SILICON
              VALLEY BANK
	 	 	 
	 	 	 
	By	           
              	 	By	          
              
	 	
              President
                or Vice President

            	 	Title	             
              
	 	 	 	 	 
	 	 	 	 	 
	 	 	 	 	 
	“Borrower”:	 	 	 
	 	 	 	 
	NORTH AMERICAN
              SCIENTIFIC,
              INC.
A California corporation	 	 	 
	 	 	 	 	 
	 	 	 	 	 
	By	             
              	 	 	 
	 	
              President
                or Vice President

            	 	 	 


    

    


     

    
      
         

      

      
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