Radiation Therapy for Uterine Sarcomas
Radiation therapy uses high-energy radiation (such as x-rays) to kill cancer cells. These treatments may be given externally in a procedure that is much like having a diagnostic x-ray. This is called external beam radiation therapy.
Radiation therapy also may be given by placing radioactive materials near the tumor. This is called brachytherapy. Women treated with this type of radiation do not remain radioactive after the implant is removed. In some situations, both brachytherapy and external beam radiation therapy are given.
When the tumor can be seen growing through the cervix, radiation therapy can be given before surgery to make it easier to completely remove the cancer. Radiation may also be given after surgery to lower the chance of the cancer coming back in the pelvis. This is called adjuvant radiation. It may be done for cancers that are high grade or when cancer cells are found in the lymph nodes. In those cases, the entire pelvis may be treated with external beam radiation therapy about 4 to 6 weeks after surgery. Sometimes the radiation field will also include an area of the abdomen called the para-aortic field. This is the area in the abdomen around the aorta (the main artery).
Radiation may be done in a woman who can’t have surgery because of other health problems.
External beam radiation therapy
External beam radiation therapy is the more familiar type of treatment in which the radiation is delivered from an outside source. This therapy is usually given 5 days a week for 4 or 5 weeks. The skin covering the area that is exposed to radiation is carefully marked with permanent ink or injected dye, similar to a tattoo. A special mold of the pelvis and lower back is custom-made to ensure that the woman is placed in the exact same position for each treatment. The actual external beam radiation treatment takes less than 30 minutes.
Brachytherapy places radioactive materials close to the area to be treated (such as the tumor).
How much of the pelvis needs to be exposed to radiation therapy depends on the extent of the disease. In cases where only the upper third of the vagina (the vaginal cuff) needs to be treated, radioactive material is inserted through the vagina. This is called vaginal brachytherapy.
For this treatment, a cylinder with a source of radiation is inserted into the vagina. The length of the cylinder (and the amount of the vagina treated) can vary, but the upper part of the vagina is always treated. With this method, the radiation mainly affects the vagina in the area in contact with the cylinder. Nearby structures such as the bladder and rectum get less radiation exposure.
This procedure is done in the radiation suite of the hospital or care center. About 4 to 6 weeks after the hysterectomy, the surgeon or radiation oncologist inserts a special applicator into the woman's vagina, and pellets of radioactive material are inserted into the applicator. There are 2 types of brachytherapy: low-dose rate (LDR) and high-dose rate (HDR).
In LDR brachytherapy, the radiation sources are usually left in place for between 1 and 4 days at a time. The patient needs to stay immobile to keep the radiation sources from moving during treatment, and so she is usually kept in the hospital on strict bed rest. More than one treatment may be necessary.
In HDR brachytherapy, the radiation is more intense. Each dose takes a very short period of time (usually less than an hour), and the patient can return home the same day. For uterine cancers, HDR brachytherapy is often given weekly or even daily for at least 3 doses.
Side effects of radiation therapy
Short-term side effects of radiation therapy include:
- Nausea and vomting
- Loose stools or diarrhea
- Skin changes
- Low blood counts
Serious fatigue, which may not occur until a few weeks after treatment begins, is a common side effect.
Skin changes are also common, with the skin in the treated area looking and feeling sunburned. As the radiation passes through the skin to its intended target, it may damage the skin cells. This can cause irritation that ranges from temporary and mild redness to permanent discoloration. The skin may release fluid, which can lead to infection, so care must be taken to clean and protect the area exposed to radiation.
As long as a woman is not bleeding heavily from a tumor in her bladder, rectum, uterus, cervix, or vagina, she can still continue to have sex during the course of pelvic radiation therapy. However, the outer genitals and vagina may become sore and tender to touch, and many women choose to stop having intercourse for a while to let the area heal.
Diarrhea is a common side effect, but it can usually be controlled with over-the-counter medicines. Nausea and vomiting may also occur but can be treated with medicines. Side effects tend to be worse when chemotherapy is given with radiation.
Radiation can also lead to low red blood cells (anemia) and low white blood cells (leukopenia). The blood counts usually return to normal after radiation is stopped.
If you are having any side effects from radiation, discuss them with your cancer care team. There are things you can do to get relief from these symptoms or prevent them.
Long-term side effects of radiation
Radiation can also lead to some side effects that can last a long time.
Radiation can irritate the bladder and may cause problems with urination. Bladder irritation, called radiation cystitis, can cause discomfort and an urge to urinate frequently.
Radiation therapy may also cause scar tissue to form in the vagina. If the scar tissue makes the vagina shorter or more narrow it is called vaginal stenosis. This can make vaginal intercourse 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 sexual intercourse 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 intercourse can be long-term side effects from radiation. For more information about dealing with the sexual side effects of radiation, see our document Sexuality for the Woman With Cancer.
Pelvic radiation can damage the ovaries, resulting in premature menopause. However, most women being treated for uterine sarcoma have already gone through menopause, either naturally or as a result of surgery to treat the cancer.
Radiation to the pelvis can impair fluid drainage from the legs, leading to leg swelling. This is known as lymphedema and is more common in women who had lymph nodes removed during surgery. More information about lymphedema can be found in our document Understanding Lymphedema for Cancers Other Than Breast Cancer.
Pelvic radiation can also weaken bones, leading to fractures of the hips or pelvic bones. It is important that women who have had pelvic radiation contact their doctor right away if they have pelvic pain. Such pain might be caused by a fracture, recurrent cancer, or other serious conditions.
For more information, see our document Understanding Radiation Therapy: A Guide for Patients and Families.
Last Medical Review: May 12, 2014 Last Revised: February 15, 2016