OBJECTIVES: This study examined patterns of recurrence after low-dose-rate prostate brachytherapy (LDR-PB), estimated local recurrence rate and compared that rate to the estimated local recurrence rate after radical prostatectomy (RP).
METHODS AND MATERIALS: A prospective database was maintained with clinical, dosimetric, and outcome data for all LDR-PB implantation procedures performed at our institution. From 1998 to 2008, 2223 patients with prostate cancer received LDR-PB without supplemental external beam radiation therapy. Patients who developed Phoenix-defined biochemical failure were reviewed for sites of relapse and investigations completed.
RESULTS: At a median follow-up of 5 years, 108 of 2223 patients (4.8%) developed biochemical relapse. In 1 additional patient, local relapse was found on transurethral prostate resection, but his prostate-specific antigen concentration was well short of triggering Phoenix-defined failure. Of the 109 patients with disease relapse, 18 of 2223 (0.8%) had a proven local recurrence, and 30 of 2223 (1.3%) had a proven distant recurrence. The remaining 61 of 2223 patients (2.7%) had unidentified sites of recurrence; of these, 57 patients (93%) had digital rectal examinations (DREs), 18 (30%) had post-treatment biopsies, 45 (74%) had bone scans, and 34 (56%) had computed tomography imaging of the abdomen and pelvis. If every biochemical failure were local, the local recurrence rate would be as high as 4.9%; however, by excluding those with proven distant failure and those with both a negative DRE and biopsy, we estimate that the local recurrence rate is 2.7% or less.
CONCLUSIONS: In the context of limitations of the study design, our population-based analysis indicates that the local recurrence rate after LDR-PB is as low or lower than that after RP in our jurisdiction.
Lo AC, Morris WJ, Pickles T, Keyes M, McKenzie M, Tyldesley S. Are you the author?
Department of Radiation Oncology, British Columbia Cancer Agency Vancouver Centre, Vancouver, British Columbia, Canada; Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
Reference: Int J Radiat Oncol Biol Phys. 2015 Mar 15;91(4):745-51.