Radiation Therapy for Uterine (Endometrial) Cancer

External Beam Radiation

External beam radiation therapy is often given 5 days a week for 4 to 6 weeks. The skin covering the treatment area is carefully marked with permanent ink or tiny tattoos. A special mold of the pelvis and lower back is custom made to make sure you are in the exact same position for each treatment. Each treatment takes less than a half-hour, but daily visits to the radiation center are needed.

Sometimes chemotherapy is given along with the radiation to help it work better. This is called chemoradiation.

Radiation of a Tumor

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Brachytherapy

This type of radiation can be delivered right to the area. This allows a high dose of radiation to reach the cancer. There will also be smaller effect on healthy tissue like bladder or rectum. A device with radioactive materials is placed in the upper part of the vagina.

Vaginal brachytherapy is done at 2 rates:

• High-dose rate—Generally takes less than one hour. Does not require a hospital stay. The 3 doses can be done in 3 days. They may also be spread out over the course of 3 weeks.
• Low-dose rate—Device is left in place for up to 4 days. A hospital stay may be needed since you will need to be immobile. This option is not often used in the US.

Side Effects and Management

Short-term side effects

Common side effects of radiation therapy include tiredness, upset stomach, or loose stools. Severe fatigue, which may not start until about 2 weeks after treatment begins, is also common. Medicine can help to manage other side effects like diarrhea, nausea and vomiting. These side effects are more common with external beam radiation than with brachytherapy.

Side effects tend to be worse when chemotherapy is given with radiation. Skin changes can include:

• Mild redness
• Peeling
• Blistering
• Skin may release fluid, which can lead to infection
• Skin in the treated area may become darker or harder as it heals

Radiation can irritate:

• Bladder (radiation cystitis)—can cause problems urinating, discomfort, blood in the urine, and an urge to urinate often.
• Intestine—cause diarrhea and cramping
• Rectum (radiation proctitis)—can cause discomfort and bleeding. Sometimes treated with enemas that contain a steroid (like hydrocortisone) or suppositories that contain an anti-inflammatory.
• Vagina (radiation vaginitis)—lead to discomfort and drainage. Doctor may recommend douching with a dilute solution of hydrogen peroxide. Can lead to open sores which may need to be treated with an estrogen cream.

Radiation can also lead to low blood counts, causing anemia (low red blood cells) and leukopenia (low white blood cells). The blood counts usually return to normal within a few weeks after radiation is stopped.

Long-term side effects

Radiation therapy may cause changes to the lining of the vagina leading to vaginal dryness. This is more common after vaginal brachytherapy than after pelvic radiation therapy.

In some cases scar tissue can form in the vagina. The scar tissue can make the vagina shorter or more narrow (called vaginal stenosis), which can make sex (vaginal penetration) painful. A woman can help prevent this problem by stretching the walls of her vagina several times a week. This can be done by having sex 3 to 4 times a week or by using a vaginal dilator (a plastic or rubber tube used to stretch out the vagina). Still, vaginal dryness and pain with sex can be long-term side effects of radiation. Some centers have physical therapists who specialize in pelvic floor therapy which can help to treat these vaginal symptoms and sometimes improve sexual function.

Pelvic radiation can damage the ovaries and cause early menopause. Many women with endometrial cancer will have already gone through menopause, either naturally or as a result of surgery to treat the cancer. If you plan on having children, talk to your doctor. There may be options to preserve fertility before starting treatment.

Pelvic radiation can cause blockages of fluid draining out of the leg. This can lead to severe swelling, called lymphedema. Lymphedema is a long-term side effect. It doesn't go away after radiation is stopped. In fact it may not start for several months or even years after treatment ends. This side effect is more common if pelvic lymph nodes were removed during treatment. There are specialized physical therapists who can help treat this. It's important to start treatment right away.

Radiation to the pelvis can weaken the bones. This will increase the risk of fractures of the hips or pelvis.

Pelvic radiation can also lead to long-term problems with the bladder or bowel. Rarely, bowel damage can cause a blockage. An abnormal connection can also form between the bowel and the vagina or outside skin. These conditions may need to be treated with surgery.