High-dose-rate (HDR) brachytherapy may be a suitable option for men with localized prostate cancer who previously have undergone transurethral resection of the prostate (TURP), according to researchers in Taiwan.
Used in combination with a reduced dose of external beam radiotherapy (EBRT), it can achieve the same oncologic outcomes as a conventional dose of EBRT but with a significantly lower incidence of major post-radiation genitourinary (GU) complications
Investigators at Chang Gung Memorial Hospital-Kaohsiung Medical Center enrolled 59 men who had a history of TURP and underwent radiation therapy for localized prostate cancer. Of these, 34 underwent HDR brachytherapy in combination with EBRT and 25 underwent EBRT alone. Two to three weeks after seed implantation, men in the HDR brachytherapy group received an EBRT dose of 45-57.6 Gy. The EBRT-only group received a dose of 63.2-75.6 Gy.
The average interval from TURP to radiation treatment was 2.7 months and 2.3 months for the HDR brachytherapy and EBRT-only groups, respectively.
After an average follow-up period of 60 months, the researchers, led by Fumin Fang, MD, Director of the Department of Radiology, observed grade 3 GU complications in 8.8% of the HDR brachytherapy group compared with 44% of the EBRT-only group, according to an online report in International Urology and Nephrology. The five-year urinary incontinence rates were 2.9% and 24%, respectively. The differences between the groups were significant. In multivariate analyses, patients who received EBRT alone had a nearly 10-fold increased risk of grade 3 GU toxicities compared with patients in the HDR brachytherapy group. The study found no significant difference in biochemical relapse-free survival (82.4% vs. 72%).
Dr. Fang’s team noted that TURP has been considered a contraindication for EBRT because of the high risk of genitourinary complications associated with this modality.