Treatment of localized prostate cancer using high-intensity focused ultrasound

Objective

To evaluate the biochemical disease-free survival (DFS), predictors of clinical outcome and morbidity of patients with localized prostate cancer treated with high-intensity focused ultrasound (HIFU), a noninvasive treatment that induces complete coagulative necrosis of a tumour at depth through the intact skin.

Patients and Methods

In all, 63 patients with stage T1c-2bN0M0 localized prostate cancer underwent HIFU using the Sonablate™ system (Focus Surgery, Inc., Indianapolis, IN, USA). None of the patients received neoadjuvant and/or adjuvant therapy. Biochemical recurrence was defined according to the criteria recommended by the American Society for Therapeutic Radiology and Oncology consensus definition, i.e. three consecutive increases in prostate-specific antigen (PSA) level after the nadir. The median (range) age, PSA level and follow-up were 71 (45–87) years, 8.5 (3.39–57.0) ng/mL and 22.0 (3–63) months, respectively.

Results

The overall biochemical disease-free rate was 75% (47 patients). The 3-year biochemical DFS rates for patients with a PSA level before HIFU of<10, 10.01–20 and >20 ng/mL were 82%, 62% and 20% (P< 0.001), respectively. The 3-year biochemical DFS rates for patients with a PSA nadir of <0.2, 0.21–1 and >1 ng/mL were 100%, 74% and 21% (P< 0.001), respectively. Final follow-up sextant biopsies showed that 55 (87%) of the patients were cancer-free. Multivariate analysis showed that the PSA nadir (P< 0.001) was a significant independent predictor of relapse.

Conclusion

HIFU therapy appears to be a safe, effective and minimally invasive therapy for patients with localized prostate cancer, and the PSA nadir is a useful predictor of clinical outcome.