Low‐dose‐rate brachytherapy for prostate cancer: A 15‐year experience in Japan

Abstract

The history of prostate brachytherapy has passed one century. In 1983, modern low‐dose‐rate prostate brachytherapy using a transrectal ultrasound‐guided procedure was introduced. In the early 1990s, low‐dose‐rate brachytherapy was introduced and rapidly spread across the USA due to its excellent oncological control, cost‐effectiveness and technically easy procedure. Since low‐dose‐rate brachytherapy was introduced in Japan (2003), over 15 years have passed. More than 43 000 patients have undergone low‐dose‐rate brachytherapy. Japanese urologists and radiation oncologists are on course with leading brachytherapists in the USA. A nationwide prospective cohort study, J‐POPS, was initiated in 2005. The J‐POPS group also provides educational programs including an annual novel training course in low‐dose‐rate brachytherapy to familiarize urologists, radiation oncologists and pathologists with the procedure. Important information on Japanese patients has accumulated, especially by the J‐POPS study group. The Japanese investigators reported excellent oncological outcomes of low‐dose‐rate brachytherapy, showing equivalent or superior efficacy to surgery in low‐ to intermediate‐risk patients, and superior efficacy in high‐risk patients using the surgery biochemical recurrence definition (prostate‐specific antigen cut‐off value of 0.2 ng/mL). Two randomized controlled studies (SHIP study: intermediate risk, and TRIP study: high risk) carried out by the J‐POPS group are ongoing, and an additional follow‐up study (J‐POPS 2 study) has been started to evaluate survival outcomes over longer follow‐up periods. Low‐dose‐rate brachytherapy is expected to provide a survival benefit, which must be confirmed by further studies with longer follow‐up periods in the future.