Radiation Therapy for Cervical Cancer

Radiation therapy uses high energy x-rays to kill cancer cells. Depending on the stage of the cervical cancer, radiation therapy may be used:

• As a part of the main treatment. For some stages of cervical cancer, the preferred treatment is radiation and chemo given together (called concurrent chemoradiation) as the chemo helps the radiation work better.
• To treat cervical cancer that has spread or that has come back after treatment. Radiation therapy may be used to lessen symptoms caused by cervical cancers that have spread to other organs and tissues.

The types of radiation therapy most often used to treat cervical cancer are:

• External beam radiation
• Brachytherapy

It is important to know that smoking increases the side effects from radiation and can make treatment less effective. If you smoke, you should stop.

External beam radiation

External beam radiation therapy (EBRT) aims x-rays at the cancer from a machine outside the body. Treatment is much like getting a regular x-ray, but the radiation dose is stronger.

Each radiation treatment lasts only a few minutes, but getting you into place for treatment usually takes longer. The procedure itself is painless.

When EBRT is used as the main treatment for cervical cancer, it is usually combined with chemotherapy (called concurrent chemoradiation). Often, a low dose of the chemo drug called cisplatin is used. Other chemo drugs can be used as well. The radiation treatments are given 5 days a week for about 5 weeks. The chemotherapy is given at scheduled times while radiation is being given. The schedule is determined by which drug is used. If the cancer has not spread to distant areas, brachytherapy, which is discussed below, may also be given after the concurrent chemoradiation is complete. 

EBRT can also be used as the main treatment of cervical cancer in patients who can’t tolerate chemoradiation, can’t safely have surgery, or choose not to have surgery. It can also be used by itself to treat areas where the cancer spread.

Possible side effects of EBRT

Short-term side effects of external beam radiation therapy for cervical cancer can include:

• Fatigue (tiredness)
• Upset stomach
• Diarrhea or loose stools (if radiation is given to the pelvis or abdomen)
• Nausea and vomiting
• Skin changes (mild redness to peeling in the area where the radiation is given)
• Radiation cystitis: Radiation to the pelvis can irritate the bladder (radiation cystitis), causing discomfort, an urge to urinate often, and sometimes blood in the urine.
• Vaginal pain: Radiation can make the vulva and vagina more sensitive and sore, and sometimes causes a discharge.
• Menstrual changes: Pelvic radiation can affect the ovaries, leading to menstrual changes and even early menopause.
• Low blood cell counts: Anemia (low levels of red blood cells) can make you  feel tired. Neutropenia (low levels of white blood cells) increases the risks of serious infection. Thrombocytopenia (low levels of platelets) increases the risk of bleeding. 

When chemotherapy is given with radiation, the blood cell counts tend to be lower and fatigue and nausea tend to be worse. These side effects typically improve in the weeks after treatment is stopped.

Other, long-term side effects are also possible with EBRT. These are described below.

Brachytherapy (internal radiation therapy)

Brachytherapy, or internal radiation therapy, puts a source of radiation in or near the cancer. This type of radiation only travels a short distance. The type of brachytherapy used most often to treat cervical cancer is known as intracavitary brachytherapy. The radiation source is placed in a device in the vagina (and sometimes in the cervix). Brachytherapy is mainly used in addition to EBRT as a part of the main treatment for cervical cancer. Rarely, it might be used alone in very specific cases of early-stage cervical cancers.

There are two types of brachytherapy:

• Low-dose rate (LDR) brachytherapy is completed over a few days. During this time, the patient stays in bed in a private room in the hospital with instruments holding the radioactive material in place. While the radiation therapy is being given, the hospital staff will care for you, but will also take precautions to avoid being exposed to radiation themselves.
• High-dose rate (HDR) brachytherapy is done as an outpatient procedure over several treatments (often at least a week apart). For each high-dose treatment, the radioactive material is inserted for a few minutes and then removed. The advantage of HDR treatment is that you do not have to stay in the hospital or stay still for long periods of time.

To treat cervical cancer in women who have had a hysterectomy, the radioactive material is placed in a tube in the vagina.

To treat someone who still has a uterus, the radioactive material can be placed in a small metal tube (called a tandem)that goes in the uterus, along with small round metal holders (ovoids) placed near the cervix. This is sometimes called tandem and ovoid treatment.

Another option is called tandem and ring. For this, a round holder (like a ring) is placed close to the uterus. The choice of which one to use depends on what type of brachytherapy is planned.

Possible short-term side effects of brachytherapy

Since the radiation only travels a short distance with brachytherapy, the main effects of the radiation are on the cervix and the walls of the vagina. The most common side effect is irritation of the vagina. It may become red and sore, and there may be a discharge. The vulva may become irritated as well.

Brachytherapy can also cause many of the same side effects as EBRT, such as fatigue, diarrhea, nausea, irritation of the bladder, and low blood cell counts. Often brachytherapy is given right after external beam radiation (before the side effects can go away), so it can be hard to know which type of treatment is causing the side effect.  

Long-term side effects of radiation therapy

Side effects related to radiation can sometimes occur months to years after treatment.

Vaginal stenosis: Both EBRT and brachytherapy can cause scar tissue to form in the vagina. The scar tissue can make the vagina narrower (called vaginal stenosis), less able to stretch, or even shorter, which can make vaginal sex painful.

Vaginal stenosis can be helped or prevented by stretching the walls of the vagina several times a week, either by having sex or by using a vaginal dilator (a plastic or rubber tube used to stretch out the vagina). .

Vaginal dryness: Vaginal dryness and painful sex can be long-term side effects from radiation (both brachytherapy and EBRT). Estrogens used locally may help with vaginal dryness and changes to the vaginal lining, especially if radiation to the pelvis damaged the ovaries, and caused early menopause. These hormones are typically applied in the vagina and absorbed into the genital area, rather than taken by mouth. They come in gel, cream, ring, and tablet forms.

For more information on vaginal stenosis and dryness see Sex and the Adult Female with Cancer.

Rectal bleeding/rectal stenosis: Radiation to the rectal wall can cause chronic inflammation of the area which can lead to bleeding and sometimes stenosis (narrowing) of the rectum which can be painful. An abnormal opening (called a fistula) also may form between the rectum and vagina, causing stool to come out of the vagina. These problems typically happen during the first 3 years after radiation treatment. Additional treatments, such as surgery, may be needed to fix these complications.

Urinary problems: Radiation to the pelvis can cause chronic radiation cystitis (as mentioned above), blood in the urine, or an abnormal opening between the bladder and vagina (called a fistula). These side effects can be seen many years after radiation therapy.

Weakened bones: Radiation to the pelvis can weaken the bones, leading to fractures. Hip fractures are the most common and might occur 2 to 4 years after radiation. Bone density tests are recommended to monitor the risk of fracture.

Swelling of the leg(s): If pelvic lymph nodes are treated with radiation, it can lead to fluid drainage problems in the leg. This can cause the leg to swell severely, a condition called lymphedema.

If you are having side effects from radiation treatment, discuss them with your cancer care team.