Exhibit
      10.1    

     

    FIRST
      AMENDMENT 

    TO

    LOAN
      AGREEMENT

     

    This
      First Amendment to Loan Agreement is entered into as of October 18, 2007 (the
      “Amendment”), by and between AGILITY CAPITAL, LLC (“Agility”) and NORTH AMERICAN
      SCIENTIFIC, INC. (“Borrower”).

     

    RECITALS

     

    Borrower
      and Agility are parties to that certain Loan Agreement dated as of September
      21,
      2007 (the “Agreement”). The parties desire to amend the Agreement in accordance
      with the terms of this Amendment. 

     

    Now,
      Therefore,
      the
      parties agree as follows:

     

    1. Total
      Credit Amount       
       Total Credit Amount is increased to $1,000,000.

     

    2. Advances
      and Payments. 
       Section 1 (a) Advances
      is
      hereby modified in full as follows:

     

    
      	 	
              (a)

            	
              Advances.
                Borrower may request one or more advances (each, an “Advance” and
                collectively, the “Advances”) on a revolving basis, up to the following
                maximum outstanding amounts: 

            


    

     

    
      	 	
              (i)

            	
              Advance
                in the principal amount of up to $500,000 upon the execution of all
                original loan documents.

            


    

     

    
      	 	
              (ii)

            	
              Advance
                of up to $500,000 upon the completion of this First Amendment to
                Loan
                Agreement.

            


    

     

    3. On
      the
      date hereof, Borrower shall deliver a Warrant to Purchase Stock to Lender in
      substantially the form attached, in exchange for Lender’s returning to Borrower
      the Warrant to Purchase Stock dated September 21, 2007.

     

    4. Notwithstanding
      anything to the contrary in the Agreement, Agility hereby consents to the
      Borrower incurring up to $500,000 of subordinated unsecured indebtedness to
      John
      Friede or an entity owned or controlled by him (“Friede”), provided that Friede
      executes and delivers to Agility, on
      Agility’s standard form with such changes thereto as are acceptable to Agility
      in its good faith business judgment, a subordination agreement pursuant
      to which the debt owed by Borrower to Friede will be subordinated to the debt
      owed to Agility.

     

    5. Unless
      otherwise defined, all initially capitalized terms in this Amendment shall
      be as
      defined in the Agreement. The Agreement, as amended hereby, shall be and remain
      in full force and effect in accordance with its respective terms and hereby
      is
      ratified and confirmed in all respects. Except as expressly set forth herein,
      the execution, delivery, and performance of this Amendment shall not operate
      as
      a waiver of, or as an amendment of, any right, power, or remedy of Agility
      under
      the Agreement, as in effect prior to the date hereof. Borrower ratifies and
      reaffirms the continuing effectiveness of all instruments, documents and
      agreements entered into in connection with the Agreement.

     

    
      
         

      

      
        1

        
          

        

      

      
         

      

    

    6. Borrower
      represents and warrants that the representations and warranties contained in
      the
      Agreement are true and correct as of the date of this Amendment, and that no
      Event of Default has occurred and is continuing.

     

    7. This
      Amendment may be executed in two or more counterparts, each of which shall
      be
      deemed an original, but all of which together shall constitute one
      instrument.

     

    8. As
      a
      condition to the effectiveness of this Amendment, Agility shall have received,
      in form and substance satisfactory to Agility, the following:

     

    
      	 	
              a.

            	
              this
                Amendment, duly executed by
                Borrower;

            


    

     

    
      	 	
              b.

            	
              a
                Warrant to Purchase Stock in substantially the form
                attached;

            


    

     

    
      	 	
              c.

            	
              Corporate
                Resolutions to Borrow;

            


    

     

    
      	
            	d.	
              payment
                of a loan modification and extension fee of $10,000, due and payable
                on
                execution of this agreement; and

            


    

     

    
      	
            	e.	
              such
                other documents, and completion of such other matters, as Agility
                may
                reasonably deem necessary or
                appropriate.

            


    

     

    In
      Witness Whereof,
      the
      undersigned have executed this Amendment as of the first date above
      written.

     

    
      
        	 	
                NORTH
                  AMERICAN SCIENTIFIC, INC.

              
	 	 
	 	
                By:
                  /s/James W.
                  Klingler                                                                    
                  

              
	 	
                Title:
                  Sr. V.P. & Chief Financial
                  Officer                                             

              
	 	 
	 	 
	 	
                AGILITY
                  CAPITAL, LLC

              
	 	 
	 	
                By:
                  /s/Daniel
                  Corry                                                                              
                  

              
	 	
                Title:
                  Chief Credit
                  Officer                                                                    
                  

              


      

      


      
        
           

        

        
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