Mid-term outcome of permanent prostate iodine-125 brachytherapy in Japanese patients

• Published in: International journal of urology Vol. 21; no. 5; pp. 473 - 478
• Main Authors: Kimura, Takahiro, Kido, Masahito, Miki, Kenta, Yamamoto, Toshihiro, Sasaki, Hiroshi, Kuruma, Hidetoshi, Hayashi, Norihiro, Takahashi, Hiroyuki, Aoki, Manabu, Egawa, Shin
• Format: Journal Article
• Language: English
• Published: Australia Blackwell Publishing Ltd 01.05.2014
• Subjects: Aged; Aged, 80 and over; Asian Continental Ancestry Group; Brachytherapy - methods; Humans; Iodine Radioisotopes - therapeutic use; Japanese patients; low-dose rate brachytherapy; Male; Middle Aged; prostate cancer; Prostatic Neoplasms - radiotherapy; Radiotherapy Dosage; Time Factors; Treatment Outcome; prostate cancer; Japanese patients; low-dose rate brachytherapy
• ISSN: 0919-8172; 1442-2042
• DOI: 10.1111/iju.12347

Objectives To analyze mid‐term oncological outcomes of low‐dose rate brachytherapy in Japanese patients. Methods Between 2003 and 2010, 604 consecutive patients with clinically localized prostate cancer were treated with low‐dose rate brachytherapy at Jikei University Hospital in Tokyo, Japan. Median follow up was 48 months. Of these patients, 260 (43%) were treated with neoadjuvant therapy, 45 (7.5%) with adjuvant hormonal therapy and 75 (12.4%) with supplemental external beam radiation therapy. Biochemical recurrence was defined as the prostate‐specific antigen nadir plus 2 ng/mL. Results Of the 604 patients, 219 (36.2%) were low risk, 361 (59.8%) were intermediate risk and 24 (4.0%) had high‐risk disease. The median biologically effective dose was 174.4 Gy2. At 8 years, biochemical recurrence‐free survival, cancer‐specific survival, and overall survival were 82.2%, 100% and 95.6%, respectively. Biochemical recurrence‐free survival at 8 years was 89.9%, 79.4% and 52.5%, for the low‐, intermediate‐, and high‐risk groups, respectively. Biochemical recurrence‐free survival for the high‐risk group was significantly lower than the low‐ and intermediate‐risk groups (P < 0.001). Biochemical recurrence‐free survival did not differ significantly by biologically effective dose stratification. In multivariate analysis, younger age (P = 0.045), higher prostate‐specific antigen (P = 0.004), higher Gleason score (P = 0.006) and higher clinical T stage (P = 0.008) were significant covariates associated with biochemical recurrence. The addition of hormonal therapy or external beam radiation therapy was associated with significantly better outcomes than low‐dose rate brachytherapy monotherapy (P = 0.0021 and 0.010). Just four patients experienced G3 genitourinary or gastrointestinal toxicity. Conclusions Low‐dose rate brachytherapy results in excellent mid‐term oncological outcomes and acceptable toxicity in Japanese patients. In our experience, biologically effective dose does not represent a significant predictor for biochemical recurrence.