Major advancements in the field of medical oncology are dramatically improving the quality of life and survival rate for cancer patients. Radioimmunotherapy combines immunotherapy, the targeted use of monoclonal antibodies created in the laboratory, with radiation therapy distributed in an intense, highly targeted manner.
Additional radiation given to patients who have already undergone chemotherapy or radiation therapy would cause major organ damage. This treatment gives a very localized dose of radiation, bound specifically to areas containing the tumor, that subsequently eliminates the tumor and limits the possibility of damage to other organs.
Sinai Hospital patients receive radioimmunotherapy treatment intravenously as outpatients. A molecule containing a radioactive agent is attached to the end of the monoclonal antibody, traveling through the bloodstream and binding to the tumor. The radioactive agent then sends radioactivity several millimeters to the tumor, reaching cells that the antibody alone would never reach. By targeting cells on the surface of the tumor, the inner portions of the tumor can be reached and ultimately destroyed. As the tumor cells begin dying, the monoclonal antibody can destroy even more cancerous cells. The two most common radioactive agents used today in radioimmunotherapy are Yitrium90 and Iodine131.
For lymphomas, which typically invade the bone marrow and are unreachable by standard radiation, radioimmunotherapy reaches the inside of the bone marrow through the bloodstream.
Radioimmunotherapy may affect some normal cells, causing lower red and white blood cell counts or bone marrow damage, which may make patients more susceptible to infection. Patients are assessed for weeks after treatment, and growth factors may be prescribed to quickly raise white and red blood cell counts as needed.
The Alvin & Lois Lapidus Cancer Institute at LifeBridge Health is currently participating in a study on the effect of Zevalin, an investigational radioimmunotherapy, in lymphoma patients who already have failed other treatment for the disease. While too early for conclusive results to date, one-third to nearly one-half of all patients nationwide participating in the clinical study are entering long-term remission following treatment.
New data is showing that a combination of more than one monoclonal antibody may be even more effective in treating certain cancers, creating a synergy that hits the tumor from a number of directions. The Alvin & Lois Lapidus Cancer Institute at LifeBridge Health is poised to participate in future clinical trials in this area, particularly for lung and colon cancers.