A multicenter evaluation of biochemical relapse free survival outcomes for intra-operatively planned prostate brachytherapy using an automated delivery system
Menée à partir de données portant sur 2 608 patients atteints d'un cancer de la prostate à risque intermédiaire de récidive (âge médian : 64 ans ; durée médiane de suivi : 4,7 ans), cette étude multicentrique évalue l'efficacité, du point de vue de la survie sans récidive biochimique, d'une curiethérapie à faible débit de dose mise en place durant l'intervention chirurgicale et utilisant un système automatisé de délivrance de doses radioactives
Purpose : To report biochemical recurrence in prostate cancer treated with intraoperatively planned low dose rate prostate brachytherapy using an automated delivery system (IO-LDRB). Methods : Between 2003 and 2013, 2608 patients from 3 centers were treated with IO-LDRB as single modality treatment for low or low-tier intermediate risk prostate cancer. Databases from the three centers have been analyzed. These independent databases were collected prospectively. Patient, tumor and treatment characteristics were then compared and Kaplan-Meier survival estimates of biochemical relapse free survival (bRFS) were generated and the Cox Proportional Hazards model was used to determine factors predicting for relapse. Results : 2608 patients with a median follow-up of 4.7 (IQR: 3.1-6.9) years were analyzed. Median age was 64 (Range: 42-84) years. In these patients, median initial PSA was 5.5 ng/mL, 74% were T1 and 26% were T2. 73% were Gleason 6 and 25% Gleason 7. Median % of biopsy cores positive was 33%, and median gland volume was 34.2cc. 11% of patients received hormones for a median of 3.0 months prior to implantation. Median seed activity was 0.437 mCi, D90 was 186.7 Gy and V100 was 99.37%. Biochemical relapse was observed in 124 patients (4.8%) and median time to failure was 4.0 years. Predicted bRFS was 93% at 7 years. On cox regression bRFS was dependent only on D90 at the time of implantation and PSA density. Conclusions : IO-LDRB is an effective treatment option for patients with low and low-tier intermediate risk prostate cancer. Rates of biochemical relapse remain low several years post treatment. These results compared favorably with manual preplan technique results published.