Pathological, Oncologic and Functional Outcomes of a Prospective Registry of Salvage High Intensity Focused Ultrasound Ablation for Radiorecurrent Prostate Cancer.

Abstract

In this prospective registry we prospectively assessed the oncologic, functional and safety outcomes of salvage high intensity focused ultrasound for radiorecurrent prostate cancer. A total of 81 men were prospectively recruited and evaluated at regular scheduled study visits to 6 months after high intensity focused ultrasound and thereafter as per standard of care. Transrectal ultrasound guided biopsy was performed at 6 months. The primary end point was absence or histological persistence of disease at 6-month biopsy. Secondary end points included quality of life, biochemical recurrence-free survival, overall survival, cancer specific survival and progression to androgen deprivation therapy. Survival analysis was performed according to the Kaplan-Meier method and multivariate analysis was performed using the log rank (Mantel-Cox) test. Mean ± SD prostate specific antigen before high intensity focused ultrasound was 4.06 ± 2.88 ng/ml. At 6 months 63 men underwent biopsy, of whom 22 (35%) had residual disease. At a mean followup of 53.5 ± 31.6 months median biochemical recurrence-free survival was 63 months. The 5-year overall and cancer specific survival rates were 88% and 94.4%, respectively. Nadir prostate specific antigen less than 0.5 ng/ml was a significant predictor of biochemical recurrence-free survival (p=0.014, 95% CI 1.22-5.87). I-PSS significantly increased (p <0.001) while IIEF-5 scores decreased and the SF-36 score did not change significantly. The rate of rectal fistulization and severe incontinence was 3.7% each. A total of 223 complications were recorded in the 180 days after high intensity focused ultrasound (Clavien-Dindo grade 1-195, grade II-20, grade III-7, grade IVa-1). Salvage high intensity focused ultrasound appears to be a viable treatment option for radiorecurrent prostate cancer, with acceptable morbidity.