Evaluation of functional outcomes after a second focal high‐intensity focused ultrasonography (HIFU) procedure in men with primary localized, non‐metastatic prostate cancer: results from the HIFU Evaluation and Assessment of Treatment (HEAT) registry

OBJECTIVES: To assess change in functional outcomes after a second focal high-intensity focused ultrasonography (HIFU) treatment compared with outcomes after one focal HIFU treatment. PATIENTS AND METHODS: In this multicentre study (2005-2016), 821 men underwent focal HIFU for localized non-metastatic prostate cancer. The patient-reported outcome measures of International Prostate Symptom Score (IPSS), pad usage and erectile function (EF) score were prospectively collected for up to 3 years. To be included in the study, completion of at least one follow-up questionnaire was required. The primary outcome was comparison of change in functional outcomes between baseline and follow-up after one focal HIFU procedure vs after a second focal HIFU procedure, using IPSS, Expanded Prostate Cancer Index Composite (EPIC) and International Index of Erectile Function (IIEF) questionnaires. RESULTS: Of 821 men, 654 underwent one focal HIFU procedure and 167 underwent a second focal HIFU procedure. A total of 355 (54.3%) men undergoing one focal HIFU procedure and 65 (38.9%) with a second focal HIFU procedure returned follow-up questionnaires, respectively. The mean age and prostate-specific antigen level were 66.4 and 65.6 years, and 7.9 and 8.4 ng/mL, respectively. After one focal HIFU treatment, the mean change in IPSS was -0.03 (P = 0.02) and in IIEF (EF score) it was -0.4 (P = 0.02) at 1-2 years, with no subsequent decline. Absolute rates of erectile dysfunction increased from 9.9% to 20.8% (P = 0.08), leak-free continence decreased from 77.9% to 72.8% (P = 0.06) and pad-free continence from 98.6% to 94.8% (P = 0.07) at 1-2 years, respectively. IPSS prior to second focal HIFU treatment compared to baseline IPSS prior to first focal HIFU treatment was lower by -1.3 (P = 0.02), but mean IPSS change was +1.4 at 1-2 years (P = 0.03) and +1.2 at 2-3 years (P = 0.003) after the second focal HIFU treatment. The mean change in EF score after the second focal HIFU treatment was -0.2 at 1-2 years (P = 0.60) and -0.5 at 2-3 years (P = 0.10), with 17.8% and 6.2% of men with new erectile dysfunction. The rate of new pad use was 1.8% at 1-2 years and 2.6% at 2-3 years. CONCLUSION: A second focal HIFU procedure causes minor detrimental effects on urinary function and EF. These data can be used to counsel patients with non-metastatic prostate cancer prior to considering HIFU therapy.