Radiation therapy for uterine cancer

Internal radiation therapy (brachytherapy)

Internal radiation therapy may be used after a hysterectomy to deliver radiation directly to the top of the vagina (vaginal vault) from inside your body. This is known as vaginal vault brachytherapy. 

During each treatment session, a plastic cylinder (the applicator) is inserted into the vagina. The applicator is connected by plastic tubes to a machine that contains a small, radioactive seed (made of metal). Next, this seed moves from the machine into the applicator where it delivers a targeted dose of radiation to the area affected by cancer. After a few minutes, the seed is drawn back into the machine. The applicator is taken out of the vagina after each session.

This type of brachytherapy does not need any anaesthetic. Each treatment session usually takes only 20–30 minutes. You are likely to have 3–6 treatment sessions as an outpatient over 1–2 weeks.

If you are having radiation therapy as the main treatment and haven’t had a hysterectomy, the internal radiation therapy may involve placing an applicator inside the uterus. This is done under anaesthetic or sedation, and may require a short hospital stay.

External beam radiation therapy

External beam radiation therapy (EBRT) directs the radiation at the cancer and surrounding tissue from outside the body. For cancer of the uterus, the lower abdomen and pelvis are treated, but if the cancer has spread (metastasised), other areas may also be treated. 

Planning for EBRT may involve several visits to your doctor to have more tests, such as blood tests and scans. Your radiation therapy team will give you instructions on preparing your bowel and bladder before planning scans and treatment sessions. 

Each EBRT session lasts about 30 minutes, with the treatment itself taking only a few minutes. You will lie on a treatment table under a large machine known as a linear accelerator, which delivers the radiation. The treatment is painless (like having an x-ray) but may cause side effects. 

If you are having EBRT, you will probably have daily treatments, Monday to Friday, for 5–6 weeks as an outpatient. It’s very important that you attend all of your scheduled sessions to ensure you receive enough radiation to make the treatment effective.

Side effects of radiation therapy

The side effects you have will vary depending on the type and dose of radiation, and the areas treated. Brachytherapy tends to have fewer side effects than EBRT. Side effects often get worse during treatment and just after the course of treatment has ended. Short-term side effects usually get better within weeks of finishing treatment.

Short-term side effects

Fatigue – Your body uses a lot of energy to recover, and travelling to treatment can also be tiring. The fatigue may last for weeks after treatment ends.

Bladder and bowel changes – Radiation therapy can cause inflammation and swelling of the bowel (radiation proctitis) and bladder (radiation cystitis). Bowel movements may be more frequent, urgent or loose (diarrhoea), or you may pass more wind than usual. Less commonly, there may be blood in the faeces (poo or stools); talk to your treatment team if you notice this. You may also pass urine more often or with more urgency. 

Nausea and vomiting – Because the radiation therapy is directed near your abdomen, you may feel sick (nauseous), with or without vomiting, for several hours after each treatment. Your doctor may prescribe anti-nausea medicine to help prevent this.

Vaginal discharge – Radiation therapy may cause or increase vaginal discharge. Let your treatment team know if the discharge smells or has blood in it. Do not wash inside the vagina with water or other fluids as this may cause infection.

Skin redness, soreness and swelling – The vulva and the skin in the groin area may become sore and swollen. The area may look pink or red and feel itchy, and then peel, blister or weep. Your treatment team will recommend creams and pain relief to use. Wash the vulva with lukewarm water or weak salt baths; avoid perfumed products; and wear loose-fitting, cotton underwear.

Long-term or late effects of radiation therapy

Some side effects can continue for longer. Other side effects may not show up until many months or years after treatment. These are called late effects.

Hair loss – You may lose your pubic hair. Sometimes, this can be permanent. Radiation therapy to the pelvis will not 
affect the hair on your head or other parts of your body.

Bladder and bowel changes – Bowel changes, such as diarrhoea, wind or constipation, and bladder changes, such as frequent or painful urination, can arise months or years after treatment. Bleeding from the bowel or bladder can also occur. In rare cases, there may be loss of bowel control (faecal incontinence) or blockage of the bowel. Let your doctor know about any bleeding or if you have pain in the abdomen and difficulty opening your bowels (pooing).

Lymphoedema – Radiation can scar the lymph nodes and vessels and stop them draining lymph fluid properly from the legs, making the legs swollen. This can occur months or years after radiation therapy. The earlier lymphoedema is found, the easier it is to treat. Look for early signs in the legs, including feelings of tightness or heaviness; tighter clothing; skin pitting; and swelling that comes and goes. 

Narrowing of the vagina – The vagina can become drier, shorter and narrower (vaginal stenosis), which may make sex and pelvic examinations uncomfortable or difficult. Your treatment team will suggest ways to prevent this.

Menopause – If you are premenopausal, radiation therapy to the pelvis can stop the ovaries producing hormones, causing early menopause. Your periods will stop, you will no longer be able to become pregnant and you may have menopause symptoms.