Brachytherapy is a type of radiation therapy often used after surgery to treat endometrial cancer and other types of cancers that affect the reproductive organs (called gynecologic cancers). Your cancer care team may recommend brachytherapy to help lower the risk of recurrence (when cancer comes back).

Keep reading to learn how brachytherapy works, who might need it, and what side effects to watch for.

1. Brachytherapy Is Also Known as Internal Radiation Therapy

Radiation therapy uses high-energy X-rays to kill cancer cells. Brachytherapy is also known as internal radiation therapy because it delivers radiation treatment from inside the body using a cylinder (called an applicator) filled with radioactive material. When internal radiation therapy is given through the vagina, it’s called vaginal brachytherapy.

The other main type of radiation therapy for endometrial cancer is external beam radiation therapy (EBRT). In this therapy, radiation is delivered from a machine outside the body. Compared to EBRT, vaginal brachytherapy can deliver a higher dose of radiation therapy to a smaller area because it’s much closer to the cancer.

2. Brachytherapy Is Usually Performed After Surgery

Most people who get brachytherapy for endometrial cancer receive this treatment as an adjuvant therapy. An adjuvant therapy is cancer treatment that’s given after the main treatment. For most people with endometrial cancer, surgery is the primary treatment.

The type of surgery you have depends on the type and stage of endometrial cancer. The standard treatment is a total hysterectomy, where the uterus and cervix are removed. However, more advanced endometrial cancer may require a radical hysterectomy, where the upper vagina and some surrounding tissues are also removed.

Some people may also need a radical hysterectomy with bilateral salpingo-oophorectomy, where both fallopian tubes and ovaries are also removed. You’ll have several weeks to heal from surgery before you start vaginal brachytherapy.

Even if the surgeon removes as much cancer as possible during surgery, some cancer cells may still be too small to see or remove. Brachytherapy can help kill cancer cells that remain after surgery and help stop the cancer from returning (called recurrence).

Brachytherapy may be combined with other adjuvant treatments, including EBRT and chemotherapy. Hormone therapy, immunotherapy, and targeted therapy may be added to the treatment plan for people with advanced endometrial cancer.

Brachytherapy as Primary Treatment

Vaginal brachytherapy may be part of your main treatment plan if you choose not to have surgery or if medical conditions make surgery unsafe. When brachytherapy is given as your main treatment, it’s usually combined with other treatments, such as EBRT and chemotherapy.

In rare cases, brachytherapy can also be given before surgery for people with advanced cancer. Brachytherapy before surgery may be recommended if testing reveals that the cancer has spread too far to be fully removed with surgery.

Doctors can now use a more precise type of brachytherapy called image-guided brachytherapy. This approach uses CT or MRI scans to help place the radiation exactly where it’s needed.

3. Brachytherapy May Be Recommended for People With Risk Factors for Recurrence

Surgery may be the only treatment needed for some people with early-stage endometrial cancer. However, about 15 percent to 20 percent of people with endometrial cancer may have a recurrence after a hysterectomy and primary treatments.

Studies have found that most people with early-stage endometrial cancer who don’t receive any adjuvant therapy experience recurrence in the vagina. Recurrence often occurs in the vaginal cuff — the upper part of the vagina where the uterus used to connect to the vagina before a hysterectomy. Vaginal brachytherapy can help lower the chance of the cancer returning in vaginal tissue.

Vaginal brachytherapy may be recommended as part of the treatment plan for people with risk factors for recurrence, such as:

• Advanced-stage endometrial cancer
• Cancer that’s spread to deeper layers of the endometrium (uterine lining) or myometrium (muscle layer of the uterus)
• Cancer that has spread to the lymph nodes
• Age over 60
• Higher grade of endometrial cancer
• Serous or clear cell type of endometrial cancer

4. Vaginal Brachytherapy Is Given by a Radiation Oncologist

A radiation oncologist is a doctor who oversees radiation therapy for people with cancer. Your radiation oncologist can recommend the best type and dose of radiation for you.

During brachytherapy, your radiation oncologist will place a cylinder-shaped applicator into your vagina. The applicator fits somewhat like a tampon. Inserting the applicator usually isn’t painful, but you might feel some pressure or discomfort. The size of the applicator depends on your radiation dose and which parts of your vagina need treatment. The vaginal cuff is always treated.

The applicator is connected to a machine outside your body. This machine holds a small radioactive pellet that travels into the applicator for the prescribed amount of time. Once the treatment is complete, the pellet returns to the machine.

5. Brachytherapy Is Given in a Hospital or Outpatient Radiation Clinic

The location you receive brachytherapy depends on what type of brachytherapy you’re getting. Low-dose rate (LDR) brachytherapy is given in a hospital, while high-dose rate (HDR) brachytherapy can be given in an outpatient radiation clinic.

Low-Dose Rate Brachytherapy

If you’re having LDR brachytherapy, the applicator must stay in place for one to four days. While the applicator is in place, you won’t be able to move around much. You’ll stay in the hospital during this treatment to make sure the applicator stays in place and to allow your care team to monitor for complications, such as blood clots. LDR brachytherapy is rarely used in the United States.

High-Dose Rate Brachytherapy

Most people can go home soon after HDR brachytherapy, so it can be given in an outpatient clinic. HDR brachytherapy involves a stronger dose of radiation that’s given for a shorter amount of time, usually 10 to 20 minutes. Most people will receive at least three doses of HDR brachytherapy, given every day or once a week.

6. The Side Effects of Brachytherapy Are Usually Limited to Nearby Tissues

Any type of radiation therapy can cause side effects when healthy tissues near the treatment area are affected by the radiation. You may not have any side effects right away. However, some side effects may start to develop within two weeks of receiving brachytherapy. Radiation therapy can have short and long-term side effects.

Brachytherapy Short-Term Side Effects

The most common short-term side effect of vaginal brachytherapy is radiation vaginitis. This can happen if radiation irritates the lining of the vagina, causing discomfort and vaginal discharge. In severe cases, radiation vaginitis can cause open sores in the vagina leading to infections.

Irritation can also occur in the bladder (radiation cystitis) or rectum (radiation proctitis). However, vaginal brachytherapy usually doesn’t affect the bladder and rectum as often as EBRT.

Short-term radiation therapy side effects are more common in people getting EBRT or when brachytherapy is combined with chemotherapy. Other possible side effects of brachytherapy include:

• Vaginal bleeding
• Diarrhea
• Pain while urinating
• Blood in the urine
• Low blood counts

Brachytherapy Long-Term Side Effects

Vaginal dryness is the most common long-term side effect of vaginal brachytherapy. If scar tissue forms in the vagina, it can cause vaginal stenosis. Vaginal stenosis is when the vagina becomes shorter and more narrow, which can make intercourse (sex) more painful.

Other long-term side effects of radiation therapy are more common in people who had EBRT, including:

• Premature menopause
• Swollen legs
• Weakened bones
• Bowel or bladder problems

7. Side Effects of Brachytherapy Are Manageable

Your cancer care team will try to minimize the side effects of radiation therapy during your treatment. If you do experience side effects, it’s important to communicate with your cancer care team so they can help you manage them.

If you develop radiation vaginitis, your cancer care team may recommend douching with a prescribed solution or creams to place on the sores. Other short-term side effects — such as diarrhea, nausea, and vomiting — can be managed with over-the-counter or prescription medications.

Sexual side effects related to vaginal dryness and vaginal stenosis can also be managed with the right support. Make sure to talk to your cancer care team about any new or bothersome symptoms you have after brachytherapy.

Talk With Others Who Understand

On MyEndometrialCancerTeam, the site for people with endometrial cancer and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with the condition.

Have you had brachytherapy for endometrial cancer? What advice do you have for others who need brachytherapy? Share your experiences in the comments below or by posting to your Activities page.