Date reviewed: 08/12/2004
Hyperthermia in Cancer Treatment: Questions and Answers
- What is 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
(1). By killing cancer cells and damaging proteins
and structures within cells (2), hyperthermia may shrink tumors.
Hyperthermia is under study in clinical trials (research studies
with people) and is not widely available (see Question
5).
- How is hyperthermia used to treat cancer?
Hyperthermia is almost always used with other forms of cancer therapy,
such as radiation therapy and chemotherapy (1, 3). 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)
(1, 3, 4, 5, 6, 7). Many of these studies, but not all, have shown
a significant reduction in tumor size when hyperthermia is combined
with other treatments (1, 3, 6, 7). However, not all of these studies
have shown increased survival in patients receiving the combined treatments
(3, 5, 7).
- What are the different methods of hyperthermia?
Several methods of hyperthermia are currently under study, including
local, regional, and whole-body hyperthermia (1, 3, 4, 5, 6, 7, 8,
9).
- 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:
- 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.
- 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.
- 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.
- 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.
- 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.
- 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 (1, 2). To ensure that the desired
temperature is reached, but not exceeded, the temperature of the tumor
and surrounding tissue is monitored throughout hyperthermia treatment
(3, 5, 7). 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 (5).
- Does hyperthermia have any complications or side effects?
Most normal tissues are not damaged during hyperthermia if the temperature
remains under 111°F. However, due to regional differences in tissue
characteristics, higher temperatures may occur in various spots. This
can result in burns, blisters, discomfort, or pain (1, 5, 7). Perfusion
techniques can cause tissue swelling, blood clots, bleeding, and other
damage to the normal tissues in the perfused area; however, most of
these side
effects are temporary. Whole-body hyperthermia can cause more
serious side effects, including cardiac
and vascular disorders, but these effects are uncommon (1, 3, 7).
Diarrhea,
nausea, and vomiting are commonly observed after whole-body hyperthermia
(7).
- What does the future hold for hyperthermia?
A number of challenges must be overcome before hyperthermia can be
considered a standard treatment for cancer (1, 3, 6, 7). Many clinical
trials are being conducted to evaluate the effectiveness of hyperthermia.
Some trials continue to research hyperthermia in combination with
other therapies for the treatment of different cancers. Other studies
focus on improving hyperthermia techniques.
To learn more about clinical trials, call the National Cancer Institute’s
(NCI) Cancer Information Service at the telephone number listed below
or visit the clinical trials page of the NCI’s Web site at http://www.cancer.gov/clinical_trials/
on the Internet.
Selected References
- van der Zee J. Heating the patient: A promising approach? Annals
of Oncology
2002; 13:1173–1184.
- Hildebrandt B, Wust P, Ahlers O, et al. The cellular and molecular
basis of hyperthermia. Critical Reviews in Oncology/Hematology
2002; 43:33–56.
- Wust P, Hildebrandt B, Sreenivasa G, et al. Hyperthermia in combined
treatment of cancer. The Lancet Oncology 2002; 3:487–497.
- Alexander HR. Isolation perfusion. In: DeVita VT Jr., Hellman S,
Rosenberg SA, editors. Cancer: Principles and Practice of Oncology.
Vol. 1 and 2. 6th ed. Philadelphia: Lippincott Williams and Wilkins,
2001.
- Falk MH, Issels RD. Hyperthermia in oncology. International
Journal of Hyperthermia 2001; 17(1):1–18.
- Dewhirst MW, Gibbs FA Jr, Roemer RB, Samulski TV. Hyperthermia.
In: Gunderson LL, Tepper JE, editors. Clinical Radiation Oncology.
1st ed. New York, NY: Churchill Livingstone, 2000.
- Kapp DS, Hahn GM, Carlson RW. Principles of Hyperthermia. In: Bast
RC Jr., Kufe DW, Pollock RE, et al., editors. Cancer Medicine
e.5. 5th ed. Hamilton, Ontario: B.C. Decker Inc., 2000.
- Feldman AL, Libutti SK, Pingpank JF, et al. Analysis of factors
associated with outcome in patients with malignant
peritoneal mesothelioma undergoing surgical debulking and intraperitoneal
chemotherapy. Journal of Clinical Oncology 2003; 21(24):4560–4567.
- Chang E, Alexander HR, Libutti SK, et al. Laparoscopic continuous
hyperthermic peritoneal
perfusion. Journal of the American College of Surgeons
2001; 193(2):225–229.
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Related Resources
Publications (available at http://www.cancer.gov/publications)
National Cancer Institute (NCI)
Resources
- Cancer Information Service (toll-free)
- Telephone: 1–800–4–CANCER (1–800–422–6237)
- TTY: 1–800–332–8615
- Online
- NCI's Web site: http://www.cancer.gov/
- LiveHelp, NCI's live online assistance: https://cissecure.nci.nih.gov/livehelp/welcome.asp
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