Hyperthermia
Hyperthermia (also called thermal
therapy or thermotherapy) is a type of cancer treatment in which body tissue is
exposed to high temperatures (up to 113°F). Research has shown that high temperatures
can damage and kill cancer cells, usually with minimal injury to normal tissues.
By killing cancer cells and damaging proteins and structures within cells, hyperthermia
may shrink tumors.
Several methods of hyperthermia are currently under study, including local, regional,
and whole-body:
In local hyperthermia, heat is applied to a small area, such as a tumor,
using various techniques that deliver energy to heat the tumor. Different types
of energy may be used to apply heat, including microwave, radiofrequency, and ultrasound.
Depending on the tumor location, there are several approaches to local hyperthermia:
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External approaches are used to treat tumors that are in or just below the skin.
External applicators are positioned around or near the appropriate region, and energy
is focused on the tumor to raise its temperature.
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Intraluminal or endocavitary methods may be used to treat tumors within or near
body cavities, such as the esophagus or rectum. Probes are placed inside the cavity
and inserted into the tumor to deliver energy and heat the area directly.
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Interstitial techniques are used to treat tumors deep within the body, such as brain
tumors. This technique allows the tumor to be heated to higher temperatures than
external techniques. Under anesthesia, probes or needles are inserted into the tumor.
Imaging techniques, such as ultrasound, may be used to make sure the probe is properly
positioned within the tumor. The heat source is then inserted into the probe. Radiofrequency
ablation (RFA) is a type of interstitial hyperthermia that uses radio waves to heat
and kill cancer cells
In regional hyperthermia, various approaches may be used to heat large areas
of tissue, such as a body cavity, organ, or limb.
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Deep tissue approaches may be used to treat cancers within the body, such as cervical
or bladder cancer. External applicators are positioned around the body cavity or
organ to be treated, and microwave or radiofrequency energy is focused on the area
to raise its temperature.
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Regional perfusion techniques can be used to treat cancers in the arms and legs,
such as melanoma, or cancer in some organs, such as the liver or lung. In this procedure,
some of the patient’s blood is removed, heated, and then pumped (perfused) back
into the limb or organ. Anticancer drugs are commonly given during this treatment.
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Continuous hyperthermic peritoneal perfusion (CHPP) is a technique used to treat
cancers within the peritoneal cavity (the space within the abdomen that contains
the intestines, stomach, and liver), including primary peritoneal mesothelioma and
stomach cancer. During surgery, heated anticancer drugs flow from a warming device
through the peritoneal cavity. The peritoneal cavity temperature reaches 106–108°F.
Whole-body hyperthermia is used to treat metastatic cancer that has spread
throughout the body. This can be accomplished by several techniques that raise the
body temperature to 107–108°F, including the use of thermal chambers (similar to
large incubators) or hot water blankets.
The effectiveness of hyperthermia treatment is related to the temperature achieved
during the treatment, as well as the length of treatment and cell and tissue characteristics.
To ensure that the desired temperature is reached, but not exceeded, the temperature
of the tumor and surrounding tissue is monitored throughout hyperthermia treatment.
Using local anesthesia, the doctor inserts small needles or tubes with tiny thermometers
into the treatment area to monitor the temperature. Imaging techniques, such as
CT (computed tomography), may be used to make sure the probes are properly positioned.
Hyperthermia is almost always used with other forms of cancer therapy, such as radiation
therapy and chemotherapy. Hyperthermia may make some cancer cells more sensitive
to radiation or harm other cancer cells that radiation cannot damage. When hyperthermia
and radiation therapy are combined, they are often given within an hour of each
other. Hyperthermia can also enhance the effects of certain anticancer drugs.
Numerous clinical trials have studied hyperthermia in combination with radiation
therapy and/or chemotherapy. These studies have focused on the treatment of many
types of cancer, including sarcoma, melanoma, and cancers of the head and neck,
brain, lung, esophagus, breast, bladder, rectum, liver, appendix, cervix, and peritoneal
lining (mesothelioma). Many of these studies, but not all, have shown a significant
reduction in tumor size when hyperthermia is combined with other treatments. However,
not all of these studies have shown increased survival in patients receiving the
combined treatments.
Search for clinical trials in Georgia.
References in this section:
Adapted from the National Cancer Institute's PDQ Database: http://www.cancer.gov/cancertopics/factsheet/Therapy/hyperthermia.
(Accessed January 2011)