EXHIBIT
        4.2

    

    

      LOCK-UP
        AGREEMENT FOR

      ANTHONY
        SILVERMAN 

      


      This
        Lock-Up Agreement (the “Agreement”) is between Century Park Pictures Corp.
        (“Century Park”) and the undersigned Shareholder of Century Park. 

      


      Whereas
        Century
        Park has entered into a Merger Agreement dated May 27, 2005 with IsoRay Medical,
        Inc., a Delaware corporation (“IsoRay”), Century Park Transitory Subsidiary,
        Inc., a Delaware corporation, and certain shareholders; and 

      


      Whereas
        the
        Merger Agreement requires as a condition of IsoRay’s obligation to close that
        Mr. Silverman execute an agreement not to sell certain of the Century Park
        shares he will retain (the “Century Park Shares”) into the public market,
        therefore

      


      In
        Consideration of
        the
        Century Park Shares to be retained by the Shareholder upon the closing of
        the
        merger, Century Park and its undersigned Shareholder, with respect to the
        Century Park Shares to be retained by the Shareholder,

      


      Agree
        As Follows:

      


      	1.  	
              Mr.
                Silverman agrees not to sell thirty percent (30%) of his Century
                Park
                Shares in the public market for a period of one year from the effective
                date of the merger. Mr. Silverman also agrees that the number of
                Century
                Park Shares subject to this Agreement and the certificate numbers
                thereof
                will be added to Exhibit A immediately after the closing of the
                merger.

            


      	 	 


      	2.
               
              	
              Stop
                transfer instructions will be issued to the stock transfer agent
                for all
                shares which are the subject of this Agreement. All certificates
                representing ownership of shares with are the subject of this Agreement
                will bear the following legend:

            


       

      “Any
        sale
        or transfer of the shares represented by this certificate is subject to a
        Lock-Up Agreement between the Company and the shareholder. Any sale or transfer
        of the shares represented by this certificate must be in accordance with
        the
        terms of the Agreement and compliance with the terms of the Agreement must
        be
        established to the satisfaction of the Company.”

      


      This
        Agreement may be executed in counterparts and faxed signatures shall be accepted
        as original signatures.

      


      SIGNATURES

      


      
        	Century
                Park Pictures Corp.	 	 	 
	 	 	 	 
	By	 	 	 
	
                
    Thomas
                Scallen,
                CEO	 	 	
                
    Date


      

       

       

      SHAREHOLDER:

      
        	 	 	 	 
	 	 	 	 
	
                
    Anthony
                Silverman	 	 	
                
    Date


      

      


       

      
        
           

        

        
           

          
            

          

        

        
           

        

      

       

      AGREEMENT
        TO STAND ASIDE FROM THE PUBLIC MARKET

      EXHIBIT
        A

      


      


      
        	
                Century
                  Park Shares Subject 

              	 
	
                to
                  the Agreement 

              	 
	
                Cert.
                  # 

              	 	
                Shares
                  

              	 
	 	 	 	 	 
	 	 	 	 	 


      

      


      


      


      
        
           

        

        
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