PURPOSE: To report preliminary results of our second regimen with 45.5Gy/7 fractions aiming to reduce toxicity, compared with our first regimen with 54Gy/9 fractions, using high-dose-rate (HDR) brachytherapy as monotherapy for prostate cancer.
MATERIALS AND METHODS: From 2005 through 2010, 63 patients with localized prostate cancer were treated with HDR brachytherapy alone in 45.5Gy/7 fractions for 4days. Thirty-four patients were considered as intermediate-risk and 29 as high-risk. Thirty-seven patients also received neoadjuvant and/or adjuvant hormonal therapy. Biologically effective dose assuming α/β=1.5Gy (BED1.5) was reduced from 270Gy to 243Gy, and BED3.0 from 162Gy to 144Gy, compared to previous 54Gy/9 fractions for 5days.
RESULTS: Median follow-up time was 42months (range 13-72). Grade 2 acute toxicities occurred in six (9.5%), late toxicities in five (7.9%) patients, and Grade 3 or higher in none. Grade 2 late gastrointestinal toxicity rate was 1.6%, compared with 7.1% for the 54Gy regimen. Three-year PSA failure-free rates for intermediate- and high-risk patients were 96% and 90%, which were comparable to 93% and 85% for the 54Gy regimen.
CONCLUSIONS: Compared to the 54 Gy/9 fractions regimen, dose-reduced regimen of 45.5Gy/7 fractions using HDR brachytherapy as monotherapy preliminarily showed an equivalent or lower incidence rate for acute and late toxicities without compromising the excellent PSA failure-free rate. Further studies with more patients and longer follow-up are warranted.
Written by:
Yoshioka Y, Konishi K, Suzuki O, Nakai Y, Isohashi F, Seo Y, Otani Y, Koizumi M, Yoshida K, Yamazaki H, Nonomura N, Ogawa K. Are you the author?
Department of Radiation Oncology, Osaka University Graduate School of Medicine, Japan.
Reference: Radiother Oncol. 2013 Oct 30. pii: S0167-8140(13)00524-0.
doi: 10.1016/j.radonc.2013.10.015
PubMed Abstract
PMID: 24183062
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