Permanent prostate brachytherapy with or without supplemental external beam radiotherapy as practiced in Japan: Outcomes of 1300 patients - Abstract

PURPOSE: To report outcomes for men treated with iodine-125 (125I) prostate brachytherapy (BT) at a single institution in Japan.

METHODS AND MATERIALS: Between 2003 and 2009, 1313 patients (median age, 68 years) with clinically localized prostate cancer were treated with 125I BT. Median prostate-specific antigen level was 7.6 ng/mL (range, 1.1-43.3). T-stage was T1c in 60%, T2 in 39%, and T3 in 1% of patients. The Gleason score was < 7, 7, and >7 in 49%, 45%, and 6% of patients, respectively. Neoadjuvant androgen deprivation therapy was used in 40% of patients and combined external beam radiotherapy of 45 Gy in 48% of patients. Postimplant dosimetry was performed after 30 days after implantation, with total doses converted to the biologically effective dose. Survival functions were calculated by the Kaplan-Meier method and Cox hazard model.

RESULTS: Median followup was 67 months (range, 6-126). The 7-year biochemical freedom from failure for low-, intermediate-, and selected high-risk prostate cancers were 98%, 93%, and 81%, respectively (p < 0.001). Multivariate analysis identified the Gleason score, initial prostate-specific antigen level, positive biopsy rate, dose, and neoadjuvant androgen deprivation therapy as predictors for biochemical freedom from failure. The 7-year actuarial developing Grade 3+ genitourinary and gastrointestinal toxicity was 2% and 0.3%, respectively. Forty-four percent patients with normal baseline potency retained normal erectile function at 5 years.

CONCLUSIONS: 125I prostate BT is a highly effective treatment option for low-, intermediate-, and selected high-risk prostate cancers. Side effects were tolerable. An adequate dose may be required to achieve successful biochemical control.

Written by:
Yorozu A, Kuroiwa N, Takahashi A, Toya K, Saito S, Nishiyama T, Yagi Y, Tanaka T, Shiraishi Y, Ohashi T.   Are you the author?
Department of Radiology, Tokyo Medical Center, National Hospital Organization, Tokyo, Japan; Department of Urology, Tokyo Medical Center, National Hospital Organization, Tokyo, Japan; Department of Radiology, Keio University School of Medicine, Tokyo, Japan.

Reference: Brachytherapy. 2014 Aug 7. pii: S1538-4721(14)00573-X.
doi: 10.1016/j.brachy.2014.06.008

PubMed Abstract
PMID: 25127123 Prostate Cancer Section