A prospective clinical trial of HIFU hemiablation for clinically localized prostate cancer

Focal therapy is an emerging mini-invasive treatment modality for localized prostate cancer aimed to reduce the morbidity associated with radical therapy while maintaining optimal cancer control. We report the mid-term oncological and functional results of primary hemiablation high-intensity focused ultrasound (HIFU) in a prospective cohort of patients.

Over 8 years, hemiablation HIFU was primarily performed in 50 selected patients with biopsy-proven clinically localized unilateral, low-intermediate risk prostate cancer in complete concordance with the prostate cancer lesions identified by magnetic resonance imaging with precise loci matching on multimodal approach. Post-treatment follow-up included regular serial PSA measurements. Biochemical recurrence was reported using Stuttgart and Phoenix criteria. The latter was used as a threshold to offer whole-gland biopsies.

Complete follow-up was available for all patients and the median follow-up was 39.5 months (range: 6-94). Mean nadir PSA value was 1.6 ng ml(-1), which represents 72% reduction compared with initial PSA pre-treatment value (P<0.001). Median time to achieve PSA nadir was 3 months. Biochemical recurrence, according to Phoenix and Stuttgart definition, occurred in 28 and 36% of patients, respectively. The 5-year actuarial metastases-free survival, cancer-specific survival and overall survival rates were 93, 100 and 87%, respectively. Out of the eight patients undergoing biopsy, six patients had a positive biopsy for cancer occurring in the untreated contralateral (n=3) or treated ipsilateral lobe (n=1) or bilaterally (n=2). A Clavien-Dindo grade 3b complication occurred in two patients. Complete continence (no pads) and erection sufficient for intercourse were documented in 94 or 80% of patients, respectively.

Hemiablation HIFU therapy, delivered with intention to treat, for carefully selected patients affords mid-term promising functional and oncological outcomes. The effectiveness of this technique should be now compared with whole-gland radical therapy.