Correlation of pretreatment clinical parameters and PSA nadir after high-intensity focused ultrasound (HIFU) for localised prostate cancer.

OBJECTIVE: To determine which pretreatment clinical parameters were predictive of a low prostate-specific antigen (PSA) nadir following high-intensity focused ultrasound (HIFU) treatment. PATIENTS AND METHODS: Retrospective study of patients with clinically localised prostate cancer undergoing HIFU at a single centre between December 1997 and September 2009. Whole-gland treatment was applied. Patients also included if they had previously undergone transurethral resection of the prostate (TURP). TURP was also conducted simultaneously to HIFU. Biochemical failure based on Phoenix definition (PSA nadir + 2). Univariate and multivariate analysis of pretreatment clinical parameters conducted to assess those factors predictive of a PSA nadir ≤0.2 and >0.2 ng/ml. RESULTS: Mean (SD) follow-up was 6.2 (2.8) years; median (range) was 6.3 (1.1-12.2) years. Kaplan-Meier estimate of biochemical disease-free survival rate at 8 years was 83 and 48 % for patients achieving a PSA nadir of ≤0.2 and >0.2 ng/ml, respectively. Prostate volume and incidental finding of cancer were significant predictors of low PSA nadir (≤0.2 ng/ml). CONCLUSIONS: Prostate volume and incidental finding of cancer could be predictors for oncologic success of HIFU based on post-treatment PSA nadir.