M e s o t h e l i o m a

Hyperthermia, the use of heat, is being studied in conjunction with radiation therapy. Researchers have found that the combination of heat and radiation can increase the response rate of some tumors.
Researchers are also studying the use of radiolabeled antibodies to deliver doses of radiation directly to the cancer site (radioimmunotherapy). Antibodies are highly specific proteins that are made by the body in response to the presence of antigens (substances recognized as foreign by the immune system). Some tumor cells contain specific antigens that trigger the production of tumor-specific antibodies. Large quantities of these antibodies can be made in the laboratory and attached to radioactive substances (a process known as radiolabeling). Once injected into the body, the antibodies seek out cancer cells, which are destroyed by the radiation. This approach can minimize the risk of radiation damage to healthy cells.
The success of this technique depends on identifying appropriate radioactive substances and determining the safe and effective dose of radiation that can be delivered in this way. Two radioimmunotherapy treatments, ibritumomab tiuxetan (Zevalin®) and tositumomab and iodine 131 tositumomab (Bexxar®), have been approved for advanced adult non-Hodgkin’s lymphoma (NHL). Clinical trials of radioimmunotherapy are under way with a number of cancers, including leukemia, NHL, colorectal cancer, and cancers of the liver, lung, brain, prostate, thyroid, breast, ovary, and pancreas.
Scientific advances have led to the discovery of new targets that are being investigated to attract radioactive materials directly to cancer cells. Laboratory and clinical research is in progress using the new molecular therapeutic agents, such as gefitinib (Iressa®) and imatinib mesylate (Gleevec®), with radiation therapy.