Radiation therapy for cervical cancer

Radiation therapy uses high-energy rays or particles to destroy cancer cells. It is sometimes used to treat cervical cancer. Your healthcare team will consider your personal needs to plan the type and amount of radiation, and when and how it is given. You may also receive other treatments. Radiation therapy is used to treat all stages of cervical cancer.

Radiation therapy is often combined with chemotherapy to treat cervical cancer. This is called chemoradiation. The 2 treatments are given together during the same time period.

Radiation therapy is given for different reasons. You may have radiation therapy or chemoradiation to:

• destroy the cancer cells in the body
• destroy cancer cells left behind after surgery to reduce the risk that the cancer will come back (called adjuvant therapy)
• relieve pain or control the symptoms of advanced cervical cancer (called palliative therapy)

The doctor may suggest an ovarian transposition before having radiation therapy for women who haven’t reached menopause. This surgery moves the ovaries higher up in the abdomen. Moving the ovaries helps to protect them from damage from radiation, which can cause early menopause.

The following types of radiation therapy are most commonly used to treat cervical cancer.

During external radiation therapy (also called external beam radiation therapy), a machine directs radiation through the skin to the tumour and some of the tissue around it. It is used to treat the whole pelvis, including the connective tissue around the cervix and uterus (called parametrial tissue) and the lymph nodes. Treatments are usually given once a day for 5 days a week for about 6 or 7 weeks.

External radiation therapy is the type of radiation used in chemoradiation.

External radiation therapy may also be used before brachytherapy (a type of internal radiation therapy) to shrink the tumour. If brachytherapy can’t be given, other types of external radiation therapy may be used.

Other types of external radiation therapy that may be used are 3D conformal radiation therapy (3D-CRT) or intensity-modulated radiation therapy (IMRT). These techniques allow the radiation therapy to be delivered to the tumour with better accuracy and less damage to surrounding tissue.

Find out more about external radiation therapy.

Brachytherapy is a type of internal radiation. It uses a radioactive material called a radioactive isotope. The material is placed right into the tumour or very close to it or in the area from where the tumour was removed.

When brachytherapy is used to treat cervical cancer, the radioactive substance is usually put inside a special hollow applicator. This applicator is called an intracavitary implant because it is placed inside the vagina, or through the vagina and cervix into the uterus, or both. Depending on the procedure, local or general anesthetic is used.

If the woman still has a uterus, a rod-shaped applicator (called an intrauterine tandem) is placed inside the uterus and 2 smaller applicators are placed in the vagina. Sometimes just the tandem is used. If the woman has already had surgery to remove the cervix and uterus, an intracavitary implant can be placed inside the vagina.

Internal radiation therapy is usually given 1 to 2 weeks after external radiation therapy. In early stages of the disease, internal radiation therapy implants may be used alone.

High-dose-rate (HDR) therapy delivers a high dose of radiation over a very short period of time. A single treatment usually takes 10 to 15 minutes. Women who have HDR therapy usually have 2 to 5 treatments, each given a few days apart. In most cases the applicators are removed after each treatment.

• Cobalt and iridium are the most common radioactive substances used for HDR therapy to the cervix.
• You can have HDR therapy done as an outpatient and can go home the same day.

Low-dose-rate (LDR) therapy delivers continuous, low doses of radiation over 1 to 3 days. In most cases, the applicators are left inside the body until the treatment is done.

• Cesium is the most common radioactive substance used for LDR therapy to the cervix.
• You may have to stay in the hospital during the treatment. Special safety precautions are taken to protect others from exposure to radiation.

Radioactive materials can also be placed directly into, or very close to, the tumour. This is called interstitial radiation therapy.

Interstitial implants may be used to treat some women with cervical cancer. Thin needles containing a radioactive substance are inserted directly into the tumour and surrounding tissue.

Women are more likely to have interstitial radiation therapy if they have a uterus that makes it difficult for doctors to place an intracavitary implant, such as a scarred or irregularly shaped uterus. Women whose cancer has spread to tissue around the cervix and uterus or to the side walls of the pelvis are also more likely to have interstitial radiation therapy.

Find out more about internal radiation therapy.

Cisplatin is the most common chemotherapy drug used in chemoradiation for cervical cancer. Cisplatin and 5-fluorouracil (Adrucil, 5-FU) may also be used. It is given with external radiation therapy. The chemotherapy acts as a radiosensitizer, which means it allows the radiation to work better. Cisplatin is usually given once a week during radiation therapy. Cisplatin and 5-FU is usually given every 4 weeks during radiation therapy.

Side effects can happen with any type of treatment for cervical cancer, but everyone’s experience is different. Some people have many side effects. Other people have few or none at all.

During radiation therapy, the healthcare team protects healthy cells in the treatment area as much as possible. But damage to healthy cells can happen and may cause side effects. If you develop side effects, they can happen any time during, immediately after or a few days or weeks after radiation therapy. Sometimes late side effects develop months or years after radiation therapy. Most side effects go away on their own or can be treated, but some side effects may last a long time or become permanent.

Side effects of radiation therapy will depend mainly on the size of the area being treated, the specific area being treated, the total dose of radiation, if chemotherapy is given at the same time (chemoradiation) and the treatment schedule. Side effects of chemoradiation can be more severe than those of radiation therapy alone.

Some common side effects of radiation therapy used for cervical cancer are:

• fatigue
• skin problems including irritation of the vagina and vulva
• diarrhea
• nausea and vomiting
• bladder problems including bladder discomfort and the urge to urinate often
• low blood cell counts
• lymphedema
• osteoporosis
• sexual problems

Tell your healthcare team if you have these side effects or others you think might be from radiation therapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

Find out more about radiation therapy and side effects of radiation therapy. To make the decisions that are right for you, ask your healthcare team questions about radiation therapy.