Purpose: To describe the safety and efficacy of high-intensity focused ultrasound (HIFU) for the treatment of prostate cancer as assessed in a Phase II/III prospective multicentric clinical trial.
Patients and methods: Patients (N = 402) presenting with localized (stage T(1-2)N(0-x)M(0)) prostate cancer between 1995 and 1999 at six European sites who were not candidates for radical prostatectomy were treated with HIFU under general or spinal anesthesia. Their mean age was 69.3 +/- 7.1 (SD) years, the mean prostate volume 28.0 +/- 13.8 cc, and the mean serum prostate specific antigen (PSA) concentration 10.9 +/- 8.7 ng/mL. Nearly all (92.2%) of the patients had one to four positive biopsy samples at baseline. The Gleason scores were 2 to 4 for 13.2% of the patients, 5 to 7 for 77.5%, and 8 to 10 for 9.3%. During the follow-up, random sextant biopsies and serum PSA measurements were performed. Any positive sample in biopsies performed after the last treatment session resulted in a "HIFU failure" classification.
Results: The patients received a mean of 1.4 HIFU sessions. The mean follow-up duration was 407 days (quartile 1 135 days, median 321 days, quartile 3 598 days). The negative biopsy rate observed in the T1-2 primary-care population was 87.2%. These results were also stratified according to the usual disease-related risk classification, and as much as a 92.1% negative biopsy rate was observed in low-risk patients. Nadir PSA results correlated with prostate size and the clinical procedure.
Conclusion: These short-term results obtained on a large cohort confirm that HIFU is an option to be considered for the primary treatment of localized prostate cancer.