Transrectal ultrasound-guided interstitial radiation therapy for localized prostate cancer.

The use of interstitial implants for the treatment of low-stage prostate cancer using transrectal ultrasound guidance is evaluated in 80 patients. This outpatient procedure involves the placement of needles through a template and into the prostate. Ultrasound guidance is used to place the needles into a preselected location. The needles are loaded with a radioactive source. In this study Palladium-103 was utilized. This technique allows accurate and complete seeding of the prostate. There was a 50 percent or greater decrease in prostate size in all of the patients who were implanted. Prostate-specific antigen (PSA) levels became normal or decreased by more than 50 percent in 97 percent of the patients. Most patients experienced urethral irritative symptoms which lasted up to five months, but none of the patients experienced rectal symptoms lasting longer than a month. The mean follow-up is 11.8 months which is too brief to ascertain the effectiveness of this therapy. The method appears to be safe and may represent an alternative to external beam irradiation.