Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
One of the most difficult areas of both human and veterinary medicine today is the treatment of neoplastic disease. numerous techniques and agents have been used in this field but none are totally effective. The variability of responses to treatment is as wide as the variety of cancerous conditions. For this reason, research continues to search for safer, more effective methods of cancer therapy. One development in this area is phototherapy (PRT). This technique was expanded to include its use in pets.
Ihle, Sherri L. and Grier, Ronald L.
Iowa State University Veterinarian: Vol. 46
, Article 1.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol46/iss1/1