BRACHYTHERAPY

Brachytherapy for Gynecologic Cancers

Internal implantation radiotherapy has been used to treat cancers of the vagina, cervix, and endometrium (the lining of the uterus) for many years. One of the reasons the cure rate of these gynecologic cancers is high, compared with similar-sized cancers in other parts of the body, is that the location and growth pattern of many gynecologic cancers make them suitable for treatment with internal implantation radiotherapy. The basic approaches that are used to deliver internal implantation radiotherapy for gynecologic cancer at the University of Florida are described in this section. It is important to remember that internal implantation is only one technique for giving radiotherapy. To understand when internal implantation is used in addition to external beam radiotherapy, go to site on treatment of gynecologic cancer.

Cervical Cancer. For cancers of the uterine cervix, internal implantation is usually performed after 4 to 6 weeks of external beam radiotherapy. The goal of external beam treatments is to shrink the tumor and eliminate any cancer cells that have spread to the pelvic lymph nodes. After external beam radiotherapy is completed, internal implantation for cervix cancer is most commonly done with a device called a “tandem and ovoid” applicator. A tandem and ovoid applicator consists of a hollow metal tube (the tandem) that is inserted through the cervix into the endometrial cavity (the central cavity in the uterus). The tandem is about 10 inches long and as thin as a pencil. The ovoids are hollow metal capsules that are small enough to fit in the vagina, up against the cervix.

The tandem and ovoid applicator is inserted under anesthesia in an operating room. The tandem and ovoid internal implantation procedure takes about 30 minutes. After the procedure the patient goes to a private hospital room. Radiation therapy is given through the tandem and ovoid applicator by placing radioactive capsules inside the hollow portions of the applicator. Placement of the radioactive capsules does not cause discomfort. The length of time that a patient has to remain in the hospital with the tandem and ovoid applicator in place depends on the situation. In most cases the applicator stays in for 40 to 48 hours. Instructions for patients who will be treated for cervix cancer with internal implantation are described in more detail in "A Radiation Therapy Implant for Cervix Cancer," an informative brochure given to patients who will be having this treatment.

Endometrial Cancer. When radiotherapy is given for patients with cancer of the endometrium (the lining of the uterus), it is usually given after a hysterectomy. Radiotherapy is usually given with both external beam irradiation and internal implantation. Most patients receive three separate internal implantation treatments, separated by a week. The goal of internal implantation in this setting is to deliver a boost dose of radiation to the tissues near the upper part of the vagina. This kind of internal implantation radiotherapy is done in a special room in the radiation oncology clinic. The procedure begins by positioning the patient on a her back on a comfortable bed. A plastic applicator is placed in the vagina. The applicator is fitted to the vagina so there is little discomfort. Anesthesia is not needed. Radiation therapy is delivered with a machine (called a high-dose-rate brachytherapy machine that inserts a radioactive wire into the plastic applicator. The patient does not feel the radioactive wire go into the applicator. Radiation treatments are completed in about 15 minutes. The entire internal implantation session takes about 45 minutes. Hospitalization is not required for this type of internal implantation radiotherapy.

Vaginal Cancer: Radiotherapy for vaginal cancer is usually given with a combination of external beam irradiation and internal implantation radiotherapy. Unlike the technique of internal implantation described in the above section on endometrial cancer, internal implantation for vaginal cancer is usually done in an operating room with the patient under anesthesia. Usually, plastic needles are inserted into the tissues involved with cancer. Radiation therapy is given by placing radioactive wires inside the plastic needles. After the implantation procedure the patient stays in a private hospital room for about 48 hours with the implant and radioactive wires in position. Most patients have little discomfort during their hospital stay. The implant is removed in the patient's hospital room. Implant removal takes about 5 minutes. The patient is discharged home from the hospital a few hours after the implant is removed.