Nationwide multicenter retrospective study on high-dose-rate brachytherapy as monotherapy for prostate cancer
Menée au Japon à partir de données portant sur 524 patients atteints d'un cancer de la prostate à risque faible, intermédiaire ou élevé de récidive (durée médiane de suivi : 5,9 ans), cette étude évalue l'efficacité, du point de vue des taux actuariels de survie à 5 ans, et la toxicité d'une curiethérapie à haut débit de dose en monothérapie
Purpose : To present, analyze and discuss results of a nationwide multicenter retrospective study on high-dose-rate brachytherapy (HDR-BT) as monotherapy for low-, intermediate- and high-risk prostate cancer. Methods and materials : From 1995 through 2013, 524 patients, 73 (14%) with low-risk, 207 (40%) with intermediate-risk, and 244 (47%) with high-risk prostate cancer, were treated with HDR-BT as monotherapy at 5 institutions in XXXXX. Dose fractionations were 27 Gy/2 fractions for 69 patients (13%), 45.5 Gy/7 fractions for 168 (32%), 49 Gy/7 fractions for 149 (28%), 54 Gy/9 fractions for 130 (25%), and others for 8 (2%). Of these patients, 156 (30%) did not receive androgen deprivation therapy (ADT), 202 patients (39%) did receive ADT <1 year, 112 (21%) for 1-3 years, and 54 (10%) for >3 years. Median follow-up time was 5.9 years (range, 0.4-18.1 years), with a minimum of 2 years for surviving patients. Results : After 5 years, respective actuarial rates of no biochemical evidence of disease (bNED), overall survival (OS), cause-specific survival (CSS), and metastasis-free survival (MFS) for all patients were 92%, 97%, 99%, and 94%. For low/intermediate/high-risk patients, the 5-year bNED rates were 95%/94%/89%, the 5-year OS rates were 98%/98%/94%, the 5-year CSS rates were 98%/100%/98%, and the 5-year MFS rates were 98%/95%/90%, respectively. The cumulative incidence of late Grade 2-3 genitourinary toxicity at 5 years was 19%, and that of late Grade 3 was 1%. The corresponding incidences of gastrointestinal toxicity were 3% and 0% (0.2%). No Grade 4 or 5 of either type of toxicity was detected. Conclusions : The findings of this nationwide multicenter retrospective study demonstrate that HDR-BT as monotherapy was safe and effective for all patients with low-, intermediate- and high-risk prostate cancer.