Radiation therapy is sometimes used as an alternative to surgical removal of the prostate gland (radical prostatectomy). There are two forms of radiation therapy used in the treatment of prostate cancer:

External beam radiation therapy

External beam radiation therapy, which is administered from outside the body, uses high-energy X-rays to destroy cancer cells. Non-invasive and painless, these treatments can also be used to treat disease that has spread beyond the capsule of the prostate and into the adjacent seminal vesicles. 

All patients can expect to experience some symptoms, including urinary frequency and urgency, a diminished urinary stream or increased urination at night. Patients may also experience loose stools and diarrhea. 

Interstitial radiation (Brachytherapy)

Interstitial radiation, better known as brachytherapy, is the implantation of small, radioactive seeds directly into the prostate gland. This approach delivers a high dose of radiation to the prostate, while minimizing exposure to the adjacent healthy tissue. Unlike external beam radiation therapy, brachytherapy does not treat the seminal vesicles or the pelvic lymph nodes. The implanted seeds are designed to release doses of radiation over the following weeks or months, depending on the type of radioisotope used. 

Side-effects from brachytherapy may include urinary irritative symptoms such as frequency, urgency and nocturia, similar to those experienced following external beam radiation therapy. In addition, some patients treated with brachytherapy develop urinary retention requiring further treatment, possibly including surgery, to urinate normally. Compared with external beam irradiation and radical prostatectomy, seed brachytherapy is believed to have less effect on erectile function.

For More Information

If you have further questions about radiation therapy options, speak with your medical oncologist about which options are best for you.

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