- What is cryosurgery?
Cryosurgery (also called cryotherapy)
is the use of extreme cold produced by liquid nitrogen (or argon gas) to destroy
abnormal tissue.
Cryosurgery is used to treat external tumors, such as those on the skin. For
external tumors, liquid nitrogen is applied directly to the cancer cells with
a cotton swab or spraying device.
Cryosurgery is also used to treat tumors inside the body (internal tumors
and tumors in the bone). For internal tumors, liquid nitrogen or argon gas
is circulated through a hollow instrument called a cryoprobe, which is placed
in contact with the tumor. The doctor uses ultrasound
or MRI
to guide the cryoprobe and monitor the freezing of the cells, thus limiting
damage to nearby healthy tissue. (In ultrasound, sound waves are bounced off
organs
and other tissues to create a picture called a sonogram.)
A ball of ice crystals forms around the probe, freezing nearby cells. Sometimes
more than one probe is used to deliver the liquid nitrogen to various parts
of the tumor. The probes may be put into the tumor during surgery or through
the skin (percutaneously). After cryosurgery, the frozen tissue thaws and
is either naturally absorbed by the body (for internal tumors), or it dissolves
and forms a scab (for external tumors).
- What types of cancer can be treated with cryosurgery?
Cryosurgery is used to treat several types of cancer, and some precancerous
or noncancerous conditions. In addition to prostate and liver tumors, cryosurgery
can be an effective treatment for the following:
Cryosurgery is also used to treat some types of low-grade cancerous and noncancerous
tumors of the bone. It may reduce the risk of joint damage when compared with
more extensive surgery, and help lessen the need for amputation.
The treatment is also used to treat AIDS-related
Kaposi sarcoma
when the skin lesions
are small and localized.
Researchers are evaluating cryosurgery as a treatment for a number of cancers,
including breast,
colon,
and kidney
cancer. They are also exploring cryotherapy in combination with other cancer
treatments, such as hormone
therapy, chemotherapy,
radiation
therapy, or surgery.
- In what situations can cryosurgery be used to treat
prostate cancer? What are the side effects?
Cryosurgery can be used to treat men who have early-stage prostate cancer
that is confined to the prostate gland. It is less well established than standard
prostatectomy
and various types of radiation therapy. Long-term outcomes are not known.
Because it is effective only in small areas, cryosurgery is not used to treat
prostate cancer that has spread outside the gland, or to distant parts of
the body.
Some advantages of cryosurgery are that the procedure can be repeated, and
it can be used to treat men who cannot have surgery or radiation therapy because
of their age or other medical problems.
Cryosurgery for the prostate gland can cause side effects. These side effects
may occur more often in men who have had radiation to the prostate.
- Cryosurgery may obstruct urine
flow or cause incontinence
(lack of control over urine flow); often, these side effects are temporary.
- Many men become impotent
(loss of sexual function).
- In some cases, the surgery has caused injury to the rectum.
- In what situations can cryosurgery be used to treat
primary liver cancer or liver metastases (cancer that has spread to the liver from another part of the
body)? What are the side effects?
Cryosurgery may be used to treat primary liver cancer that has not spread.
It is used especially if surgery is not possible due to factors such as other
medical conditions. The treatment also may be used for cancer that has spread
to the liver from another site (such as the colon or rectum). In some cases,
chemotherapy and/or radiation therapy may be given before or after cryosurgery.
Cryosurgery in the liver may cause damage to the bile
ducts and/or major blood
vessels, which can lead to hemorrhage (heavy bleeding) or infection.
- Does cryosurgery have any complications or side effects?
Cryosurgery does have side effects, although they may be less severe than
those associated with surgery or radiation therapy. The effects depend on
the location of the tumor. Cryosurgery for cervical intraepithelial neoplasia
has not been shown to affect a woman's fertility,
but it can cause cramping, pain, or bleeding. When used to treat skin cancer
(including Kaposi sarcoma), cryosurgery may cause scarring and swelling; if
nerves are damaged, loss of sensation may occur, and, rarely, it may cause
a loss of pigmentation and loss of hair in the treated area. When used to
treat tumors of the bone, cryosurgery may lead to the destruction of nearby
bone tissue and result in fractures, but these effects may not be seen for
some time after the initial treatment and can often be delayed with other
treatments. In rare cases, cryosurgery may interact badly with certain types
of chemotherapy. Although the side effects of surgery may be less severe than
those associated with conventional surgery or radiation, more studies are
needed to determine the long-term effects.
- What are the advantages of cryosurgery?
Cryosurgery offers advantages over other methods of cancer treatment. It
is less invasive than surgery, involving only a small incision
or insertion of the cryoprobe through the skin. Consequently, pain, bleeding,
and other complications of surgery are minimized. Cryosurgery is less expensive
than other treatments and requires shorter recovery time and a shorter hospital
stay, or no hospital stay at all. Sometimes cryosurgery can be done using
only local
anesthesia.
Because physicians can focus cryosurgical treatment on a limited area, they
can avoid the destruction of nearby healthy tissue. The treatment can be safely
repeated and may be used along with standard treatments such as surgery, chemotherapy,
hormone therapy, and radiation. Cryosurgery may offer an option for treating
cancers that are considered inoperable
or that do not respond to standard treatments. Furthermore, it can be used
for patients who are not good candidates for conventional surgery because
of their age or other medical conditions.
- What are the disadvantages of cryosurgery?
The major disadvantage of cryosurgery is the uncertainty surrounding its
long-term effectiveness. While cryosurgery may be effective in treating tumors
the physician can see by using imaging
tests (tests that produce pictures of areas inside the body), it can miss
microscopic
cancer spread. Furthermore, because the effectiveness of the technique is
still being assessed, insurance coverage issues may arise.
- What does the future hold for cryosurgery?
Additional studies are needed to determine the effectiveness of cryosurgery
in controlling cancer and improving survival. Data from these studies will
allow physicians to compare cryosurgery with standard treatment options such
as surgery, chemotherapy, and radiation. Moreover, physicians continue to
examine the possibility of using cryosurgery in combination with other treatments.
- Where is cryosurgery currently available?
Cryosurgery is widely available in gynecologists' offices for the treatment
of cervical neoplasias. A limited number of hospitals and cancer centers throughout
the country currently have skilled doctors and the necessary technology to
perform cryosurgery for other noncancerous, precancerous, and cancerous conditions.
Individuals can consult with their doctors or contact hospitals and cancer
centers in their area to find out where cryosurgery is being used.