External Beam Radiation Therapy is a type of treatment that can be used for prostate cancer. This type of treatment works by targeting the prostate gland with beams of radiation. After your prostate has been mapped and your body has been set into place by a fitted mold, shaped beams of radiation are directed at the prostate from several directions which kills the cancer cells. There are two types of radiation that your doctor may use. These include either three dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT).

Before you have your first radiation treatment, you will have an ultrasound to gather images of your prostate. This helps your doctor identify how much radiation is needed and where in the body it needs to be targeted. During the course of treatment, there will be a small amount of radiation delivered to your body every day from outside of the body to the prostate. External beam radiation therapy is typically given on an outpatient basis and you usually have treatment about five days a week. This usually lasts for about seven to nine weeks.

Each treatment session usually lasts less than an hour, and the actual radiation treatment only takes a few minutes. During a treatment session, you will lay down in a position predetermined by your radiation simulation session. A customized immobilization device will hold you in the same position for each therapy session. Then, a linear accelerator machine will rotate around your body to deliver radiation beams to your prostate from different directions.

This procedure is recommended for men with early-stage prostate cancer and men with prostate cancer that has spread outside of the prostate to nearby tissues. The pros of having external beam radiation therapy are that there is no blood loss and there is no hospitalization required. The cons of having external beam radiation therapy are that there is fatigue associated with radiation, it requires countless treatments that can extend over many weeks, the prostate is not removed which leaves the chance of recurrence, healthy tissue can be damaged by radiation, and it can be difficult to accurately stage the cancer.

The potential side effects of having external beam radiation therapy for prostate cancer may include frequent urination, difficult or painful urination, blood in the urine, urinary leakage, abdominal cramping, diarrhea, painful bowel movements, rectal bleeding, fatigue, sexual dysfunction (including little to no sexual function or a decrease in the volume of semen), skin reactions, and secondary cancers in the area where radiation took place.