Radiation Therapy for Gynecological Cancers
Gynecological cancers include cancers of the cervix, uterus, ovaries, vagina, vulva and fallopian tubes. Over 80,000 women in the US are diagnosed with a gynecologic cancer (gynecologics cancer) each year. More than half of these are uterine cancers.
Patients with gynecologic cancer are treated by a team of physicians that may include the following:
- A gynecologic oncologist is a gynecologist who specializes in surgery for gynecologic cancers. He or she may also administer chemotherapy for gynecologic cancer.
- A radiation oncologist is a physician who is trained to use radiation therapy to treat cancer.
- A medical oncologist is a physician trained to use chemotherapy to treat cancer.
The treatment of gynecologic cancer varies depending on the site, the extent (or stage) and the patient’s overall health.
Uterine (or endometrial) cancer is usually treated with surgery to remove the uterus, fallopian tubes and ovaries. This surgery is called a hysterectomy. Depending on the findings, radiation therapy and /or chemotherapy may be added after surgery.
Ovarian cancer is usually treated with surgery to remove the ovaries, uterus and other structures in the abdomen and pelvis. Chemotherapy is often recommended after surgery. Fallopian tube cancers are rare and are treated similarly to ovarian cancers.
Cervical cancer can be treated with either a hysterectomy, or radiation therapy. If the cervical cancer is small, surgery is usually done. However, with larger tumors, radiation therapy, often given along with low-dose chemotherapy, is preferred.
Vulvar cancer is treated with surgery; radiation therapy may need to be added after surgery in certain situations. If the vulvar cancer is large, radiation therapy may be used without surgery.
Vaginal cancers are treated with radiation therapy.
Radiation Therapy for Gynecologic Cancer
External Beam Radiation Therapy
External beam radiation therapy is a series of high energy x-ray treatments delivered on a linear accelerator. The treatments are generally given daily, Monday through Friday, over several weeks. The daily treatments last about 15 to 20 minutes, and are painless.
Prior to beginning treatment, a planning session is done to define the area that needs to be treated. Usually this will involve having a CT scan done in the treatment position. Other studies, such as PET scans, MRIs or CT scans may be used to help the radiation oncologist identify the area of tumor involvement. 3-dimensional conformal radiation therapy and intensity modulated radiation therapy (IMRT) are often used to minimize the radiation dose to normal structures while still targeting the area of tumor involvement with high doses of radiation.
Brachytherapy (or internal radiation therapy) involves placing radioactive sources near or in the cancer itself. This is particularly useful for vaginal, cervical, and uterine cancers. Often this is combined with external beam radiation therapy, and depending on the type of cancer, one or more brachytherapy sessions may be required.
There are several types of brachytherapy used for gynecologic cancers. They are divided into two main categories—high dose rate, and low dose rate.
High dose rate (HDR) brachytherapy is given over the course of several treatments as an outpatient. The applicator is positioned, and a source of radiation introduced. The treatment may take only a few minutes each time.
Low dose rate (LDR) brachytherapy is delivered over 2-4 days, and involves hospitalization. The implant remains in place during the entire time, and generally the patient is confined to bed until it is removed.
Side Effects of Radiation Therapy
Radiation side effects depend on what part of the body is being treated. For patients with gynecologic cancers, the pelvic area is usually treated, but treatment may also involve the groin regions, or upper abdomen.
Radiation side effects are cumulative, that is they slowly increase with each passing week of treatment. Most patients experience some fatigue which begins around the second or third week of treatment, and increases until the radiation therapy is completed. Diarrhea, urinary frequency or burning, vaginal discharge are other common side effects. Typically these sides effects resolve within a few weeks after treatment ends.
Your doctor will review specific side effects with you depending on your particular situation and the treatment required.