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

Abstract

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 ≤ T2, PSA <15 ng/mL, Gleason score ≤7) were analysed. The median (range) follow‐up was 4.7 (2–10.9) years. The median PSA nadir was 0.13 ng/mL, which occurred at a median of 12.9 weeks after HIFU, and the median PSA at the last follow‐up was 0.76 (1.6–2.7) ng/mL. Clinical failure occurred in 71 patients (25%); 24 due to a positive biopsy and 47 through the use of an additional therapy. Biochemical events that best predicted clinical failure were ‘PSA nadir plus’ values of 1.1–1.3 ng/mL, PSA velocities of <0.3 ng/mL/year and PSA doubling times of 1.25–1.75 years. CONCLUSION A new definition of biochemical failure that is specific to patients treated with HIFU therapy is established, i.e. the ‘Stuttgart definition’, the ‘PSA nadir plus 1.2 ng/mL’.

Prostatic cancer surveillance following whole-gland high-intensity focused ultrasound: comparison of MRI and prostate-specific antigen for detection of residual or recurrent disease

“…This is consistent with several previous studies, which have correlated PSA nadir with outcome [16,17]. The results suggest that regular measurement of PSA levels will detect most residual or recurrent disease following whole-gland HIFU.…”

Transrectal high‐intensity focused ultrasound for treatment of localized prostate cancer

“…15,16 We used the Phoenix definition plus histological results as a basis for judgment of disease-free survival, since we were not satisfied with other definitions currently used to measure the efficacy of HIFU treatment. Recently, specific criteria for assessment of HIFU have been proposed (the Stuttgart criteria), 17 and we intend to compare the results based on the Phoenix-ASTRO and Stuttgart criteria in a future study.…”

HIFU as salvage first-line treatment for palpable, TRUS-evidenced, biopsy-proven locally recurrent prostate cancer after radical prostatectomy: A pilot study

“…Success was defined as PSA nadir Յ0.1 ng/ml, obtained within 3 months [14]. In case of PSA nadir Ͼ0.1 ng/ml or PSA increase Ն1 ng/ml above the PSA nadir, a biopsy of the treated lesion was performed, and if negative, hormonal therapy [maximum androgen blockade (MAB)] was adopted.…”