Improved biochemical relapse-free survival for patients with large/wide glands treated with prostate seed implantation for localized adenocarcinoma of prostate

Abstract

Objectives To analyze whether prostate size affects biochemical relapse-free survival (bRFS). Methods The bRFS outcomes for 390 patients with a minimum of 2 years of follow-up were determined from a review of a prospectively maintained database. All patients were treated with iodine-125 alone as the radiotherapeutic modality and had a minimum of four posttreatment prostate-specific antigen values. None were treated with androgen deprivation. The factors examined in the univariate and multivariate analyses predicting for bRFS included gland volume, patient age, initial prostate-specific antigen value, biopsy Gleason score, clinical stage, and postimplant dosimetric variables. Results Most patients had low-risk disease, and the median follow-up was 45 months (range 24 to 102). Using the American Society for Therapeutic Radiology Oncology definition of biochemical failure, the overall 5-year bRFS rate was 89.3%. On separate multivariate analyses, only the pretreatment prostate width and volume significantly influenced bRFS favorably ( P = 0.0069 and P = 0.0255, respectively). No association was found between gland size/width and postimplant dosimetry. Conclusions The results of our study have shown that implantation of large/wide prostates independently confers better bRFS.