Radiation Therapy for Prostate Cancer
Written by: Dr. Haake
Prostate cancer is expected to affect 238,590 men in the United States and 2013, with an estimated number of deaths at 29,720. The prostate is part of a man’s reproductive system, located in front of the rectum and under the bladder. It surrounds a tube called the the urethra, through which urine flows from the bladder. The prostate is responsible for making part of the seminal fluid that helps carry sperm during intercourse. Prostate cancer in its early stages rarely causes symptoms, though patients can have alterations in their ability to urinate from enlargement of the prostate, or have blood in the urine, or have changes in their erection capability. Cancer is often picked up by a PSA test, which subsequently leads to a biopsy. Fortunately, a large percentage of prostate cancer is found in the early stages, when it is very curable with local treatments such as surgery or radiation therapy. Patients are generally seen by a surgeon and by a radiation oncologist to help determine the best treatment for them.
Southeast Radiation Oncology staffs many centers where quality radiotherapy can be delivered, with facilities in North and in South Carolina. External beam radiation therapy for prostate cancer treatment with a machine called a linear accelerator consists of an 8 to 8 ½ week course of therapy, with treatments delivered Monday through Friday. A special type of radiation planning and targeting, called intensity modulated radiotherapy (IMRT), is utilized at all of our facilities, to minimize radiation dose to surrounding organs much better than we could even 10 years ago. Because of the ability to tailor the dose closely to the prostate, patients often receive the therapy with little or no ill effects, though some patients will get irritation to urinate, some fatigue or loose stool by the end of their treatment course. Fortunately, these symptoms are usually readily treated with medications, and are self-limited, reversing over 2-4 weeks.
In 2013, the national organization for radiation oncologists, the American Society of Therapeutic Radiation Oncology (ASTRO), publicized a notice that in select prostate cancer patients, utilization of a very short course of radiotherapy for curative treatment of prostate cancer had enough clinical followup as to be deemed a reasonable option to offer patients. This short course of treatment is also called stereotactic body radiosurgery (SBRT). It consists of a total of 5 treatments given over 2 to 3 weeks. The dose given at each treatment is higher than the standard dose given in an 8 week course of therapy, but the extraordinary accuracy allows for even less of a margin of normal tissue inclusion within the beams, allowing this therapy to be done safely. Southeast Radiation Oncology has had several years of experience using this technology at one of our facilities with a special linear accelerator called the CyberKnife, and we are pleased to offer this as yet another cutting edge method of treatment for prostate cancer patients.
Some patients are best served with a radioactive implant of the prostate using small radioisotope pellets that are implanted into the prostate, with or without supplemental external beam treatment. These implants are done under anesthesia, and several of our facilities offer this. These are done in partnership with our urologic physician colleagues. The results from treatment with a single radiation implant for appropriate patients with prostate cancer have been excellent, in excess of 90% cures reported. This type of therapy has over 15 years of followup information in the medical literature, assuring us that these treatment outcomes are permanent.
Radiation also has value in treating patients with advanced prostate cancer that has spread to other sites in the body. The initial treatment for patients with spread of prostate cancer is anti-testosterone hormone administration, a shot given every one to six months, administered by the urologist. If prostate cancer spreads or is advanced at diagnosis, the cancer has a tendency to travel to bone. Focal radiation beam therapy for a short course, one to ten treatments to an area of pain, is often effective at reducing or eliminating pain. Patients can also benefit from a new treatment with injectable intravenous Radium-223, that has been used to treat the bone sites of cancer spread by traveling by the bloodstream to the areas of disease in bone. This very targeted therapy has a minimal effect on blood counts. One of the radiation therapy facilities staffed by Southeast Radiation Oncology has been on the forefront of use and research of this agent, and has been recognized as a national leader with the experience gained with Radium-223.