Exhibit 10.81








 


August 28, 2014


 





Karlheinz Goehl-Medizintechnik Göhl


Hermann-Glockner-Str.


590763 Fuerth, Germany


Attn: Charly Goehl, CEO


 


Re: Extension of Term of the International
Distribution Agreement


 


Dear Mr. Goehl:


 


The purpose of this
letter is to confirm the extension of the term of, and changes to the payments required in, the International Distribution Agreement
entered into between IsoRay Medical, Inc., a Delaware corporation (“IsoRay”), and Karlheinz Goehl-Medizintechnik Göhl
(“Distributor”), dated as of October 31, 2011 (collectively, the “Agreement”).


 


Under the Agreement,
the Agreement’s current term, as extended by letter agreement dated August 27, 2013, expires on August 31, 2014. IsoRay and
Distributor now agree to extend the term to August 31, 2015.


 


IsoRay and Distributor
also agree to replace Exhibit A of the Agreement with the Exhibit A attached hereto, for the purpose of updating
the pricing of the Products. Distributor acknowledges and agrees that the new prices shall take effect on September 1, 2014 for
all orders received on or after September 1, 2014, and the Notice Period contained in Section 3.9 of the Agreement is hereby waived.


 


IsoRay and Distributor
further agree that Distributor shall make an additional payment annually to IsoRay equal to one-half of the annual minimum royalty
due from IsoRay to Dr. Reddy’s Laboratories (EU) Ltd. (“Dr. Reddy’s"), pursuant to IsoRay’s License
Agreement with Dr. Reddy’s dated June 1, 2011. Such payment shall be made by Distributor each year in which the Agreement
is in effect, upon receipt of an invoice from IsoRay, with payment of Distributor’s portion of the 2014 minimum royalty payable
within thirty (30) days of the date of this letter.


 


Except as set forth
herein, all terms and conditions of the Agreement shall remain in full force and effect. Each party hereto hereby expressly ratifies
and affirms all such terms and conditions as of the effective date hereof.


 






    	 



    	 



    

 





 


IsoRay and Distributor
each represent and acknowledge that it has the power and authority to enter into this letter. This letter may be executed in any
number of counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same
instrument.


 


IsoRay Medical, Inc.


 





	By	/s/ Dwight Babcock	 
	 	Dwight Babcock, CEO	 







 





The foregoing is accepted and agreed to on and as of the date
first shown above,


 


Karlheinz Goehl-Medizintechnik Göhl


 





	By	/s/ Charly Goehl	 
	 	Charly Goehl, CEO	 







 






    	 



    	 



    




 





 








Exhibit A


 


International Distribution
Agreement 


Exhibit A -Product List
and Distributor Pricing.





 





	Code 	Case Quantity 	Product Description 	Case Price (U.S.$)
	 	 	 	 
	1020 	Total of ten (10)	2.0cm GliaSite RTS 	 
	 		Catheter Tray	 
	 	 	 	 
	1030	Total of ten (10)	3.0cm GliaSite RTS 	 
	 		Catheter Tray	[**]
	 	 	 	 
	1040 	Total of ten (10) 	4.0cm GliaSite RTS 	 
	 		Catheter Tray	 
	 	 	 	 
	9005 	Total of ten (10) 	GliaSite RTS Access Tray 	[**] 
	 	 	 	 
	8150 	1 	Iotrex Radiotherapy Solution 	 
	 	 	(1 ml vial)* 	[**] 
	 	 	 	 
	To be Determined	Gripper® Infusion Set	 
	 	 	with Separate Injection Site	To be Determined



 





* 96 hours advance notice required


* Iotrex will be shipped directly to hospital
and billed to Distributor







 





Payments are due net thirty (30) days from date
of invoice


Minimum order quantity is full case







 





[**] Certain information in this document has been
omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect
to the omitted portions.