Details on all patients find more were captured on a prospective database, BrachyNet. No patients were lost to followup. At each review, patients completed standard survey forms, including International

Prostate Symptom Score (IPSS), rectal toxicity, and erectile dysfunction. Urethral stricture events were collected prospectively. A stricture was documented if a patient underwent a surgical procedure for a stricture (dilation or urethrotomy). This definition is equivalent to Grade 2 or higher Common Terminology Criteria for Adverse Events version 3 toxicity (9). The medical records and surgical report, when available, were used to identify the site of the stricture. The risk of stricture was compared among the various dose groups (the dose fractionation schedule 18 Gy/3, 20 Gy/4, 19 Gy/2, or 16 Gy/2). Potential confounding factors were identified: urinary retention (defined as requiring an in-dwelling catheter within 2 weeks following the removal of the HDRB needles), previous transurethral resection of prostate (TURP), order of the treatment (HDRB before or after EBRT), the IPSS, the radiation oncologist, and the urologist. The managing urologist was included because the definition of stricture relies on a surgical procedure.

This makes the definition of stricture subjective, and potentially the urologist’s intervention “threshold” may influence Selleck GSK126 the stricture rate. The end point was date of first stricture. Time to stricture formation was calculated from the date of HDRB implantation. Otherwise, the date for analysis was date of last followup or date of death. Analysis was done using

STATA version 8. Nelson–Aalen cumulative hazard modeling was used to estimate risk over time. Thiamine-diphosphate kinase The statistical significant of difference between hazard curves was calculated using the log-rank test. Univariate and multivariate analysis was performed using a Cox proportional regression model. A two-sided p-value of less than 0.05 was considered significant. Interactions between variables were tested by separately adding factors into the model. All variables in the univariate model were used for the multivariate analysis. A biologic model was also used to evaluate the total dose received by the urethra. Three hundred fifty-four patients were treated with an HDRB at William Buckland Radiotherapy Center (Table 1). The median age was 65 years. Low-, intermediate-, or high-risk nonmetastatic prostate adenocarcinoma made up respectively 2.5%, 65%, and 19.5% of patients. Forty-three patients received 20 Gy/4, 214 patients received 18 Gy/3, and 95 patients received 19 Gy/2. Two patients received 16 Gy/2 fractions as described above. In total, 45 patients had one or more strictures: 5 in the 20 Gy/4 group (11.6%), 20 in the 18 Gy/3 group (9.3%), and 20 in the 19 Gy/2 group (21%). Neither of the two patients who received 16 Gy developed a stricture. Thirteen patients had a dilatation, whereas 32 had an urethrotomy as initial management.