Prediction of biochemical-free survival for patients with prostate cancer after 125I brachytherapy

Purpose of the study: To improve the results of treatment of patients with localized prostate cancer using the 125I brachytherapy by means of individual prediction of relapse-free survival of patients after implantation. Materials and methods. The study included 123 patients with low and intermediate risk clinically localized prostate cancer who were implanted with 125I radioactive micro sources in the period from 2000 to 2013. The main evaluation criterion was 5-year biochemical disease free survival bDFS. Results. In the whole cohort, the 5-year bDFS was 83.7%. The results of treatment depended on the radiation dose - the bDFS was higher in the group that received a D90 of at least 140 Gy. When building a mathematical model for predicting treatment outcomes, the most significant prognostic factors were: PSA level, prostate gland volume, Gleason score, post-implant of D90 and V100. The sensitivity of the model was 0.75, the specificity was 0.96, and the area under the curve characterizing the accuracy of the model was 0.79. Authors declare lack of the possible conflicts of interests