Interstitial radiation, intracavitary radiation, or brachytherapy treatment are all forms of internal radiation therapy. Internal radiation therapy places the source of high-energy rays as close as possible to the cancer cells so that fewer normal cells are exposed to radiation. By using internal radiation therapy, the doctor can give a higher total dose of radiation in a shorter time than is possible with external treatment. Instead of using a large radiation machine, the radioactive material is placed directly into (or as close as possible to) the affected area. These implanted sources can either be left in permanently or removed once the dose has been delivered.
PROSEED Permanent Prostate Seed Implant:
Radioactive Seed Implant Therapy is an innovative outpatient cancer treatment that consists of permanent implantation of radioactive seeds into the prostate gland through the perineum for early stage prostate cancer. The implantation procedure is performed in the operating room while the patient is asleep. Thin needles are passed into the prostate gland through the skin between the scrotum and rectum. An imaging device known as an ultrasound is inserted into the rectum to visualize and guide the placement of the needles and seeds into the prostate. Radioactive Iodine-125 or Palladium-103 is encased in small, metal seeds, which are one-fifth of an inch long, pencil-lead thin, and easily seen on X-rays. These seeds are embedded in the prostate, thus producing high doses of radiation inside the gland. Each seed emits an intense amount of radiation, but only to an area about the size of a small marble. After the procedure, the patient will temporarily contain a small amount of radiation from the seeds, although this amount is not generally dangerous to most other people. Approximately one year after implantation, the radioactivity is virtually gone.
Mammosite Partial Breast Irradiation:
This new technique for administering partial breast irradiation delivers dose via a special Mammosite catheter that is placed into the lumpectomy site. This catheter has a small, soft balloon attached to the end of it that fills the lumpectomy cavity. The radioactive source is placed inside the balloon by a computer-controlled device. Because the source is inside the balloon, radiation is delivered to the area of the breast where cancer us most likely to recur. This technique utilizes high dose rate (HDR) Brachytherapy to administer the internal radiation treatment.
High Dose Rate (HDR):
This very specialized treatment involves the placement of a very small radioactive source of Iridium into the center of the tumor. This procedure involves the placement of a small catheter or applicator into the area of interest. After placement of the delivery device, check films will be made and the tumor location defined. The planned dose to the tumor is outlined, and a computer calculates the radiation dose distribution and the necessary positioning and timing of the Iridium source positions. After treatment the delivery device is removed. Patients may receive this form of treatment several times.
Low Dose Rate (LDR):
This form of radiation treatment is usually associated with the treatment of gynecological cancers such as cancer of the uterus or cervix. The procedure begins with the insertion of devices to hold radioactive Cesium sources within the uterus or vagina. After the device is properly positioned, the patient is returned to a private hospital room. Later in the day radioactive Cesium sources are inserted into the delivery device. The system usually remains in place for several days, slowly delivering radiation to the interior of the tumor. In this manner a high dose of radiation is delivered to the tumor.