Surgery, radiation, and chemotherapy are all well-known and well-established treatments for skin cancer. Another treatment that’s currently under investigation uses heat to kill melanoma and other types of cancer cells. It’s called hyperthermia.
Hyperthermia uses a controlled level of heat — between 104 and 111°F — to treat melanoma and other types of cancer. This temperature range produces changes in cancer cells that either directly cause them to die or make them more vulnerable to the effects of standard cancer treatments, like radiation and chemotherapy. The advantage of hyperthermia is that it’s less likely to damage healthy cells.
Research finds that delivering heat to tumors can help shrink them. Doctors often give hyperthermia before radiation therapy or chemotherapy to improve the effectiveness of these treatments.
How is hyperthermia given?
Heat is delivered to the tumor, organ, or region of the body from an energy source such as radiofrequency, microwave, or ultrasound. Doctors use three different hyperthermia methods to treat cancer:
Local hyperthermia delivers heat directly to the tumor. When the cancer is on or just below the skin surface, the heat is delivered from outside of the body. For tumors deeper inside the body, a probe or needle is inserted to deliver the heat.
Radiofrequency ablation (RFA) is one type of local hyperthermia treatment. It uses high-energy waves to heat the tumor. Ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI) helps guide the doctor to the tumor. A probe releases energy into the tumor for up to 30 minutes to destroy cancer cells. The dead cells eventually turn into scar tissue and shrink. RFA is usually used to treat cancer inside organs like the liver or lungs, but it might be an option for melanoma that has spread.
Regional hyperthermia heats larger areas of the body, such as an organ, arm, or leg. One type of regional hyperthermia — called regional perfusion or isolation perfusion — is being tested for melanoma in an arm or leg. To perform this technique, doctors first separate out the blood supply from that limb. Then, they use a machine to heat up the blood before delivering it back to that area. This treatment may be used together with chemotherapy.
Whole-body hyperthermia is used to treat cancers like melanoma that have spread (metastatic cancer). Doctors use heated blankets, warm water, or machines called thermal chambers to increase a patient’s body temperature. The heat is believed to stimulate the immune system to fight the cancer. Heating the whole body at once also helps chemotherapy work more effectively.
The temperature used in whole-body hyperthermia differs from study to study. Some researchers heat their patients to a temperature of 107 to 108°F.
What are the side effects and risks?
As long as the temperature stays under 111°F, it shouldn’t damage healthy tissues. However, hyperthermia can create hot spots that are much warmer. These bursts of heat can cause painful burns and blisters on the skin and inside the body. Also, some areas of the body — like the brain — are more sensitive to the effects of heat than others. Doctors try to keep the heat level steady in the treatment area by using thermometer probes to consistently monitor the temperature.
Other possible side effects depend on which type of hyperthermia treatment you have.
Side effects from local hyperthermia include:
- blood clots
- damage to skin, muscles, and nerves in the treatment area
Side effects from regional and whole-body hyperthermia include:
- heart problems
- blood vessel damage
You might also have side effects from chemotherapy or radiation if you received these treatments at the same time as hyperthermia.
Where can I get hyperthermia?
Right now, hyperthermia is only available in clinical trials at specialized cancer centers. Only doctors who have been highly trained in hyperthermia techniques can safely deliver this treatment.
Results of hyperthermia studies have so far been promising. However, researchers still need more evidence to confirm that it’s safe and effective against cancer.
If you’re interested in participating in a clinical trial of hyperthermia, ask your oncologist whether a study for your type of cancer is available in your area.