Use of TRUS to predict pubic arch interference of prostate brachytherapy.

PURPOSE To demonstrate the potential for transrectal ultrasound (TRUS) to predict pubic arch interference of transperineal needle placement for prostate brachytherapy. METHODS AND MATERIALS TRUS and pelvic computerized tomography (CT) scans from 22 patients who had transperineal prostate brachytherapy at University of Washington were analyzed for pubic arch visualization and interference. The outer margins of the prostate and the inner margins of the pubic bones from each imaging modality were outlined and compared. RESULTS The pubic arch was readily visualized by TRUS in 21 of the 22 patients. There was good correlation between TRUS and CT for evaluating the amount of pubic arch interference (r = 0.90). CONCLUSION TRUS can be substituted for CT imaging to evaluate pubic arch interference of transperineal needle placement for prostate brachytherapy. Eliminating routine CT scanning would reduce the cost of treatment.