Permanent prostate brachytherapy: Pathologic implications as assessed on radical prostatectomy specimens of broadening selection criteria for monotherapy

Objectives: To assess the impact of clinical selection criteria on pathologic features among patients treated by radical retropubic prostatectomy and to evaluate the implications of broadening eligibility for permanent prostate brachytherapy monotherapy. Methods: A consecutive series of 423 patients with prostate cancer, who underwent diagnostic biopsy and subsequent radical retropubic prostatectomy, were selected for this study. Four subgroups were defined using the American Brachytherapy Society selection criteria, including prostate size limits (group 1), no prostate size limits (group 2A), a modified set of criteria (group 2B), and clinical Stage T1-T2 (group 3). The rates of extraprostatic extension, seminal vesicle invasion, and lymph node involvement were compared. Results: Adverse pathologic features at radical retropubic prostatectomy were noted in 8 (9.3%) of 86 patients in group 1, 11 (5.6%) of 195 patients in group 2A, 35 (12.0%) of 292 patients in group 2B, and 90 (21.8%) of 413 patients in group 3. The rates of extraprostatic extension, seminal vesicle invasion, and lymph node involvement appeared comparable among groups 1 (5.8%, 3.5%, and 0.0%, respectively), 2A (3.6%, 2.1%, and 0.0%, respectively), and 2B (6.9%, 3.8%, and 1.4%, respectively), but were greater in group 3 (9.7%, 7.8%, and 4.4%, respectively). Conclusions: Judicious broadening of the clinical selection criteria may allow a greater number of patients to be eligible for permanent prostate brachytherapy monotherapy by including patients whose risk of having adverse pathologic features is comparable to that of patients currently deemed suitable for permanent prostate brachytherapy monotherapy. Prospective assessment of oncologic outcomes of such an approach is required.