The prostate is a gland, located behind the penis, which is responsible for making the fluid in semen. Prostate cancer occurs when cells in the prostate begin to grow uncontrollably and stop responding to normal growth signals. Prostate cancer is often treated initially with surgery but, as with most cancers, a variety of treatments is optimal. One common treatment for prostate cancer is radiation therapy.
Purpose
Radiation treatment is often used to treat patients with prostate cancer after they have had surgery to remove the cancer. This is because even the most successful surgeries are not always able to remove all of the cancerous tissue and require additional treatment to send the cancer into remission. Because chemotherapy generally does not work well for treating prostate cancer, radiation is often the best option for follow-up therapy.
Mechanism
Radiation treatment works by bombarding the prostate cancer cells with high energy X-ray beams. This beams are able to damage the DNA of cells, causing them to die. Although these X-rays also affect healthy cells, they damage the cancer cells more because the cancer cells divide so rapidly that they don't have as much time to repair the damage.
External Beam Therapy
One form of radiation treatment is called external beam therapy. With this kind of radiation treatment, the X-ray beams are generated from a machine outside of the body (called a linear accelerator) which is then aimed at the cancerous tissue. Before the first radiation treatment, a CT scan of the prostate is typically performed to pinpoint the exact location of the tumor. Then, the radiation machine can be accurately aimed to deliver as much radiation as possible to the tumor, with less radiation directed at healthy tissue.
Brachytherapy
Brachytherapy is another type of radiation treatment which can be used for prostate cancer. It involves surgically implanting small bits of radioactive material near the tumor. This radioactive material then emits radiation that only travels a short distance. Brachytherapy comes in two forms: low and high dosage. Low-dose brachytherapy involves pellets which are left in the body for several months. With high-dose brachytherapy, the radioactive material is left in the body for approximately 30 minutes.
Side Effects
Radiation treatment can cause irritation and itching of the skin around the prostate and near the anus (called the perineal skin). It can also cause darkening of the skin around the anus. Radiation treatment can also affect the intestines, which leads to diarrhea, gas and abdominal discomfort. Side effects of radiation on the bladder include increased frequency of urinating as well as a burning sensation during urination. Radiation therapy can also cause loss of pubic hair, fatigue and mild scarring.
