Patterns of recurrence after low-dose-rate prostate brachytherapy: a population-based study of 2223 consecutive low- and intermediate-risk patients.
OBJECTIVE
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
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.
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.
Andrea C
AC
Lo
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. Electronic address: JMorris@bccancer.bc.ca.
W James
WJ
Morris
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.
Tom
T
Pickles
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.
Mira
M
Keyes
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.
Michael
M
McKenzie
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.
Scott
S
Tyldesley
D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use; D001918:Brachytherapy / Q000379:methods*; D051517:Digital Rectal Examination; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery*
D000726:Androgen Antagonists; D007987:Gonadotropin-Releasing Hormone; D017430:Prostate-Specific Antigen