125Iodine monotherapy for Japanese men with low- and intermediate-risk prostate cancer: Outcomes after 5 years of follow-up

Data from 305 japanese men with low-risk (n = 175) or intermediate-risk (n = 130) prostate cancer who underwent 125i monotherapy were retrospectively analyzed. of the 305 patients,93 received hormonal therapy for a median of 6 months (range,1-33 months) before implantation. the prescribed dose to the prostate plus 3- to 5-mm margin was set at 145 gy. the mean dose to 90% of the prostate volume at 1 month (d90) and the prostate volume receiving at least 100% dose at 1 month (v100) were 173.4 gy and 95.8%,respectively. the median follow-up was 66 months (range,12-94 months). the 5-year biochemical non-evidence of disease rate was 95.5% (low-risk,94.2%; intermediate-risk,97.3%). the 5-year freedom from clinical failure rate was 98.9% (low-risk,98.9%; intermediate-risk,99.2%).the initial prostate-specific antigen level was identified as a significant predictive factor for biochemical recurrence (p = 0.029). the late grade 3 genitourinary toxicity rate was 2.0%. no patients displayed late gastrointestinal toxicity of grade 3 or worse. monotherapy with 125i showed excellent outcomes with limited morbidity for japanese men with low- and intermediate-risk prostate cancer after 5 years of follow-up. © 2013 the author 2013. published by oxford university press on behalf of the japan radiation research society and japanese society for therapeutic radiology and oncology.