The EBRT Procedure External beam radiation therapy (EBRT) treats prostate cancer with radiation. Before treatment starts, the doctor may order a scan or other tests to check the location and possible extension of the cancer. During the treatment, a machine targets a beam of ionizing irradiation at the target tissue. EBRT treatment seems like getting an x-ray, but it takes a much longer time. The treatment damages genetic material in all dividing cells within the target lesion. This prevents the cells from growing and they eventually die. Patients undergoing EBRT generally receive treatment at an outpatient center five days a week for six to eight consecutive weeks. EBRT selection criteria EBRT is an option when the cancer is confined to the prostate gland, it may be used alone or combined with medications or surgery. External beam radiation therapy can be curative if the cancer has not gone beyond the prostate gland.

Effectiveness of external beam radiation therapy Success rates for EBRT can range from 19 - 86%. Studies have shown success rates between 81 - 86% for low-risk disease; 26 - 60% for moderate-risk disease; and 19 - 25% for high-risk disease. To improve the success rate, EBRT is often used in conjunction with other therapies.

Stokes SH: Comparison of biochemical disease-free survival of patients with localized carcinoma of the prostate undergoing radical prostatectomy, transperineal ultrasound-guided radioactive seed implantation, or definitive external beam irradiation. Int J Radiat Oncol Biol Phys 2000, 47:129-136.

Martinez AA, Gonzalez JA, Chung AK, et al.: A comparison of external beam radiation therapy versus radical prostatectomy for patients stages with low risk prostate carcinoma diagnosed, stages, and treated at a single institution. Cancer 2000, 88:425-432.

Zagars GK, Pollack A, von Eschenbach AC: Prognostic factors for clinically localized prostate carcinoma. Cancer 1997, 79:1370-1380.

Perez CA, Michalski JM, Purdy JA, et al.: Three-dimensional conformal therapy or standard irradiation in localized carcinoma of prostate: preliminary results of a nonrandomized study. Int J Radiat Oncol Biol Phys 2000, 47:629-637.

Risks of external beam radiation therapy
External beam radiation therapy damages both cancer cells and normal cells. However, normal cells are usually able to better repair themselves and function properly more quickly than the cancer cells.
  

If the radiation damages nerves that control erections, the patient may lose his ability to get or keep an erection. Occasionally bowel function will not return immediately after treatment ends.

Recovery time for EBRT
Side effects (see below) usually disappear shortly after the 7-8 week therapy regimen ends. The patient usually can keep to daily activities during the treatment.

Side effects of EBRT
External beam radiation therapy can lead to a variety of side effects. Most are minor and disappear after therapy ends. They include: