The word hyperthermia refers to elevated body temperature. The hyperthermia technique has been used for centuries in the treatment of tumors. It wasn't until recently, however, that body temperatures could be raised in an effective and safe manner. Cancer cells are different from normal cells in many ways, including their response to heat. In most cases, these differences make it possible for hyperthermia to kill cancer cells without significantly harming normal tissue surrounding the tumor.

Although hyperthermia alone is damaging to tumors, it's most effective when used in conjunction with radiation therapy and, to a more limited extent, with chemotherapy. When used in combination with radiation therapy, hyperthermia makes it more difficult for tumor cells to repair radiation-induced damage. It also makes certain cells, normally resistant to radiation, more sensitive to the therapy. The main forms of hyperthermia used in patients with cancer currently fall into three categories:

• Whole-body systemic hyperthermia
• Regional hyperthermia
• Local, site-specific hyperthermia

Not all tumors are suitable for hyperthermia treatment. Factors such as the tumor's heat sensitivity, depth and location can limit use of the therapy. Generally, you should meet these criteria to be eligible for hyperthermia:

• The cancer is usually recurrent or advanced
• The cancer must be located within several centimeters of the skin surface
• You must be able to lie relatively flat for at least an hour

The following types of cancers may be treated with hyperthermia:

• Breast cancer
• Malignant melanoma (a type of skin cancer)
• Sarcomas (cancer in the bone, muscle or soft tissues)
• Lymphomas
• Head and neck cancers
• Other selected cancer types