Rectal complications associated with transperineal interstitial brachytherapy for prostate cancer

As transperineal interstitial permanent prostate brachytherapy (TIPPB) grows in acceptance as an option in the treatment of organ-confined prostate cancer, its associated toxicities are being defined. This clinical report documents rectal toxicity from a large cohort of men treated by a single practitioner for adenocarcinoma of the prostate.

Eight hundred twenty-five men were treated from September 1992 to September 1998 with TIPPB. One hundred-forty were treated in conjunction with external beam irradiation (EBRT) and 685 with TIPPB alone. All patients were implanted under real-time ultrasound guidance. No dose-volume histogram analysis was performed for this study. All patients were followed at 5 weeks after the procedure, then every 3-6 months thereafter. Rectal morbidity was graded by a modified RTOG toxicity scale. Therapy to control symptoms was recommended on an individual basis.

The median follow-up for the cohort is 48 months. A total of 77 patients (9.4%) reported Grade 1 toxicity at some time following an implant whereas 54 patients (6.6%) reported Grade 2 toxicity. The peak post-TIPPB time for experiencing rectal toxicity was 8 months at which time Grade 1 and 2 rectal toxicity was reported in 9.5% of the patients. This improved over the subsequent months and resolved in all patients by 312 years. Four patients (0.5%) reported Grade 3 rectal toxicity with rectal ulceration identified on colonoscopy at 1 year from implant. Two of the four patients had colonic manipulation in the radiated portion of the colon which subsequently caused it to bleed. None of the patients required blood product transfusion. In 3 of the 4 patients the Grade 3 rectal toxicity has resolved spontaneously and 1 patient continues to heal at the time of this report. No patient required hospitalization or surgical intervention.

TIPPB is a tolerable and acceptable treatment option when used alone in early-stage, organ-confined adenocarcinoma of the prostate and in conjunction with EBRT in more advanced disease. This clinical report adds to the growing literature regarding the potential morbidity associated with this procedure and indicates that serious rectal injury is rare.