High-intensity focused ultrasound for prostate cancer: comparative definitions of biochemical failure.

Overview

OBJECTIVES: To compare the specificity and sensitivity of different definitions of biochemical failure in patients treated with high-intensity focused ultrasound (HIFU) for prostate cancer, to identify the most accurate predictor of clinical failure after HIFU. PATIENTS AND METHODS: Consecutively treated patients who underwent HIFU between October 1997 and July 2006 at two centres (Lyon, France; and Regensburg, Germany) were prospectively maintained within a central database and retrospectively reviewed for this study. Clinical failure was defined as a positive prostate biopsy after treatment, radiographic evidence of lymphatic or bony metastatic disease, or salvage treatment for prostate cancer (surgery, radiation, hormonal therapy or second HIFU). The serum prostate-specific antigen (PSA) values after HIFU were assessed as a biochemical surrogate of a therapeutic success or failure. PSA threshold values, 'PSA nadir plus', PSA velocity, PSA doubling time and the American Society or Therapeutic Radiotherapy and Oncology and Phoenix definition of biochemical failure were all considered. The sensitivity, specificity, positive predictive value and negative predictive value of each biochemical definition for predicting clinical failure were determined. RESULTS: The data from 285 patients (stage