CLINICAL INVESTIGATION Prostate 10-YEAR EXPERIENCE WITH I-125 PROSTATE BRACHYTHERAPYAT THE PRINCESS MARGARET HOSPITAL: RESULTS FOR 1,100 PATIENTS JUANITA CROOK, M.D.,* JETTE BORG,PH.D., y ANDREW EVANS, M.D., z ANTS TOI, M.D., { E. P. SAIBISHKUMAR, M.D.,* SHARON FUNG, M.SC., x AND CLEMENT MA, M.SC. x Departments of *Radiation Oncology, y Radiation Physics, z Pathology, { Radiology, and x Biostatistics, Princess Margaret Hospital, Toronto, Ontario, Canada Purpose: To report outcomes for 1,111 men treated with iodine-125 brachytherapy (BT) at a single institution. Methods and Materials: A total of 1,111 men (median age, 63) were treated with iodine-125 prostate BT for low- or intermediate-risk prostate cancer between March 1999 and November 2008. Median prostate-specific antigen (PSA) level was 5.4 ng/ml (range, 0.9–26.1). T stage was T1c in 66% and T2 in 34% of patients. Gleason score was 6 in 90.1% and 7 or 8 in 9.9% of patients. Neoadjuvant hormonal therapy (2–6 months course) was used in 10.1% of patients and combined external radiotherapy (45 Gy) with BT (110 Gy) in 4.1% (n = 46) of patients. Uni- variate and multivariate Cox proportional hazards were used to determine predictors of failure. Results: Median follow-up was 42 months (range, 6–114), but for biochemical freedom from relapse, a minimum PSA test follow-up of 30 months was required (median 54; n = 776). There were 27 failures, yielding an actuarial 7- year disease-free survival rate of 95.2% (96 at risk beyond 84 months). All failures underwent repeat 12-core trans- rectal ultrasound -guided biopsies, confirming 8 local failures. On multivariate analysis, Gleason score was the only independent predictor of failure (p = 0.001; hazard ratio, 4.8 (1.9–12.4). Median International Prostate Symptom score from 12 to 108 months ranged between 3 and 9. Of the men reporting baseline potency, 82.8% retained sat- isfactory erectile function beyond 5 years. Conclusion: Iodine-125 prostate BT is a highly effective treatment option for favorable- and intermediate-risk prostate cancer and is associated with maintenance of good urinary and erectile functions. Ó 2011 Elsevier Inc. Prostate neoplasms, Brachytherapy, Prostate-specific antigen, Radiotherapy. INTRODUCTION Although multiple treatment options exist for early-stage pros- tate cancer, randomized trials comparing efficacy and quality of life are difficult to conduct (1). Treatment choices are evaluated based on a growing body of reports, often describing single- center experience (2–4), which may not be representative of global outcomes. In Canada, provision of radiotherapy is centralized and confined to a relatively small number of university-affiliated centers. Prostate brachytherapy (BT) is a ra- diation oncology procedure and is performed only at these cen- ters. Although prostate brachytherapy in the form of permanent seed implantation began in the late 1980s and by the mid 1990s was an accepted and popular modality for delivering a high and very effective dose of irradiation to the prostate (2–4), public funding in the province of Ontario was not obtained until 1999. The iodine-125 prostate brachytherapy program at Prin- cess Margaret Hospital commenced on March 1, 1999, and from its inception, demographic, dosimetric, and outcome data were prospectively recorded in a database. University and host hospital institutional review board approval was ob- tained for outcome analysis. We report our 10-year experi- ence in terms of biochemical (PSA) outcome, and urinary and sexual side effects. METHODS AND MATERIALS Patient selection A total of 1,111 consecutively treated patients with clinically local- ized prostate cancer received a permanent implant of iodine-125 seeds. All patients had biopsy-proven prostate adenocarcinoma; all external pathology was centrally reviewed by an experienced Reprint requests to: J. M. Crook, M.D., BC Cancer Agency, Cen- ter for the Southern Interior, 399 Royal Ave., Kelowna BC V1Y 5L3, Canada. Tel: (250) 712-3979; Fax: (250) 712-3911; E-mail: jcrook@bccancer.bc.ca Presented at the 51st Annual Meeting of the American Society for Therapeutic Radiology and Oncology Chicago, Illinois, Nov. 1-5, 2009 and the 30th Annual Meeting of the American Brachytherapy Society, Toronto, Canada, May 31-June 2, 2009. Conflict of interest: none. Acknowledgment—We thank Dr. Michael McLean for treatment of 16% of the patients; Dr. Joan Sweet for pathology review; and Kris- tine Grenier for reference management. Received Feb 17, 2010, and in revised form April 1, 2010. Accepted for publication April 2, 2010. 1323 Int. J. Radiation Oncology Biol. Phys., Vol. 80, No. 5, pp. 1323–1329, 2011 Copyright Ó 2011 Elsevier Inc. Printed in the USA. All rights reserved 0360-3016/$–see front matter doi:10.1016/j.ijrobp.2010.04.038