Radioimmunotherapy A new innovative cancer treatment called Radioimmunotherapy or RIT joins conventional radiation therapy with immunotherapy. RIT uses monoclonal antibodies to target specific cancer cells and minimize damage to surrounding cells and tissue. Monoclonal antibodies (MAbs) are laboratory made immune proteins engineered to attach to antigens of specific cells. These antibodies mimic antibodies naturally produced as part of the immune system. Originally MAbs were made completely from mice cells and when these were introduced into the human body, the immune system would react against them. This decreased the success rate of the treatment and many times the immune system would destroy the MAbs even before treatment could be provided. As studies progressed, researchers were able to replace mouse MAbs with a mixture of human and mouse cells called chimeric antibodies. Continued studies have now led to humanized antibodies. Humanized antibodies consist of fragments of human antibodies instead of whole ones. Researchers also found that by using smaller fragments that there was a greater chance for the antibodies to reach the targeted cells. Once the engineered MAbs have been made, radioisotopes are attached through a process called labeling. Iodine 131 (I131) and Yttrium 90 (Y90) are the most common radioisotopes used in RIT. These isotopes both emit beta particles through beta decay. Beta emission cause DNA strand breaks, therefore killing tumor cells. Iodine 131 decays with a half-life of 8 days with beta and gamma emissions. The nuclide of iodine has 78 neutrons in the nucleus. The most stable of iodine is I127 which has 74 neutrons. On decaying I131 converts to XE131. The emission of gamma radiat... ... middle of paper ... ...t for Lymphoma." The Leukemia & Lymphoma Society. 18 Mar. 2004. Web. 14 Nov. 2010 "Monoclonal Antibody Drugs for Cancer Treatment: How They Work - MayoClinic.com." Mayo Clinic Medical Information and Tools for Healthy Living - MayoClinic.com. 24 Jan. 2009. Web. 14 Nov. 2010. DeNoon, Daniel. "New AIDS Therapy Nukes HIV With Radioactive Antibodies | Natural Cures For HIV." Natural Cures for HIV-AIDS | Alternative Remedies for HIV-AIDS | Traditional HIV Treatment. Web. 22 Nov. 2010. "Monoclonal Antibodies." American Cancer Society :: Information and Resources for Cancer: Breast, Colon, Prostate, Lung and Other Forms. 12 Oct. 2010. Web. 22 Nov. 2010. "Smart-bomb’ Drugs for Lymphoma Underused." Breaking News, Weather, Business, Health, Entertainment, Sports, Politics, Travel, Science, Technology, Local, US & World News- Msnbc.com. 5 Jan. 2007. Web. 22 Nov. 2010.