Multicentric Oncologic Outcomes of High-Intensity Focused Ultrasound for Localized Prostate Cancer in 803 Patients

Background

High-intensity focused ultrasound (HIFU) is an emerging treatment for select patients with localized prostate cancer (PCa).

Objectives

To report the oncologic outcome of HIFU as a primary care option for localized prostate cancer from a multicenter database.

Design, setting, and participants

Patients with localized PCa treated with curative intent and presenting at least a 2-yr follow-up from February 1993 were considered in this study. Previously irradiated patients were excluded from this analysis. In case of any residual or recurrent PCa, patients were systematically offered a second session. Kaplan-Meier analysis was performed to determine disease-free survival rates (DFSR).

Measurements

Prostate-specific antigen (PSA), clinical stage, and pathologic results were measured pre- and post-HIFU.

Results and limitations

A total of 803 patients from six urologic departments met the inclusion criteria. Stratification according to d’Amico's risk group was low, intermediate, and high in 40.2%, 46.3%, and 13.5% of patients, respectively. Mean follow-up was 42 ± 33 mo. Mean PSA nadir was 1.0 ± 2.8 ng/ml with 54.3% reaching a nadir of ≤0.3 ng/ml. Control biopsies were negative in 85% of cases. The overall and cancer-specific survival rates at 8 yr were 89% and 99%, respectively. The metastasis-free survival rate at 8 yr was 97%. Initial PSA value and Gleason score value significantly influence the DFSR. The 5- and 7-yr biochemical-free survival rates (Phoenix criteria) were 83–75%, 72–63%, and 68–62% (p = 0.03) and the additional treatment-free survival rates were 84–79%, 68–61%, and 52–54% (p < 0.001) for low-, intermediate-, and high-risk patients, respectively. PSA nadir was a major predictive factor for HIFU success: negative biopsies, stable PSA, and no additional therapy.

Conclusions

Local control and DFSR achieved with HIFU were similar to those expected with conformal external-beam radiation therapy (EBRT). The excellent cancer-specific survival rate is also explained by the possibility to repeat HIFU and use salvage EBRT.