Radiation therapy uses high energy radiation to kill cancer cells in the body, according to the National Cancer Institute. Radiation given internally is called brachytherapy. High-dose rate, or HDR, implant treatments use a robotic machine to deliver radioactive sources directly into the prostate gland to treat cancer. No radiation remains in the body after the sources are removed and the patient is not radioactive. Treatments may be given over several days or until the prescribed dose is reached, according to the American Cancer Society.
How are HDR implant treatments given?
Using radiology examinations and treatment planning computers, the doctor determines the best dose of radiation to kill the cancer cells in the prostate gland. The doctor places hollow needles into the gland during surgery. The needles are inserted through the perineum, the area between the scrotum and the rectum. Soft catheters, or hollow tubes, are threaded through the needles and then the needles are removed. The catheters are anchored in place and remain until the treatments are finished. High dose radioactive sources, usually radioactive iridium-192 or cesium-137, are threaded into the catheters for 5 to 15 minutes for several days until the prescribed radiation dose is reached, and then the catheters are removed, according to the American Cancer Society. Patients usually stay in the hospital, but may go home between treatments. A machine called a high-dose remote afterloader is used to robotically insert and remove the sources during the treatment.
Are other radiation treatments needed?
Depending on the size of the cancer in the prostate gland, the HDR implant procedure may be used alone or in combination with external beam radiation. External beam radiation uses a machine called a linear accelerator to create high energy rays that are delivered through the skin. According to the American Cancer Society, external beam radiation used in combination with the HDR implant technique allows a lower dose of external radiation to be used. External beam radiation is not as targeted as brachytherapy, so a lower dose of external radiation may limit damage to surrounding organs, such as the bowel and bladder.
Are there side effects from HDR treatments?
After the catheters are removed, there may be pain in the perineum. Urine may be reddish-brown for about a week after the last treatment, according to the American Cancer Society. Because of the location of the prostate gland in the lower abdomen, bowel and bladder side effects may occur from the radiation but are rare. Bowel problems may include burning, pain and diarrhea. Urinary incontinence, or not being able to pass urine, occurs in a small number of patients, according to the American Society of Radiation Oncology. Impotence, or the inability to have an erection, is a very rare side effect, according to the American Cancer Society. When sexual relations resume, the semen may have a slight tinge of blood. Patients usually leave the hospital with antibiotics and pain medicine to prevent infection and to manage discomfort after the procedure. Patients should report any side effects to the doctor promptly.
