High‐intensity focused ultrasound as salvage therapy for patients with recurrent prostate cancer after external beam radiation, brachytherapy or proton therapy

Abstract

To investigate the use of high-intensity focused ultrasound (HIFU) as a salvage therapy in patients with recurrence of localized prostate cancer after external beam radiation (EBRT), brachytherapy, or proton therapy. We retrospectively reviewed the charts of all patients who had undergone salvage HIFU for biopsy-proven prostate cancer after primary radiation therapy. Patient characteristics and oncological outcomes were assessed. Records of 22 patients with a median (range) follow-up of 24 (5-80) months were reviewed. Patients were men with presumed organ-confined disease who had been treated with salvage HIFU following recurrent disease after EBRT (fourteen patients), brachytherapy (five patients: four with high-dose brachytherapy using In(192) ; and one with low-dose brachytherapy using Au(98) ) or proton therapy (three patients). The median (range) age at salvage HIFU was 65 (52-80) years, with a median (range) prostate-specific antigen (PSA) level before radiation therapy of 14.3 (5.7-118) ng/mL and a median (range) PSA level of 4.0 (1.2-30.1) ng/mL before HIFU. The median (range) period to HIFU after radiation therapy was 36 (4-96) months. The biochemical disease-free survival (bDFS) rate in all patients at 5 years was 52%. Rates of bDFS in low-, intermediate- and high-risk groups were 100%, 86%, and 14%, respectively. One of the twelve patients who received post-HIFU prostate biopsy showed malignancy. Side effects included urethral stricture in four patients, grade I urinary incontinence in four patients, rectourethral fistula and epididymitis in one of each patient. Salvage HIFU is a promising treatment option for local recurrence after radiation therapy, with morbidity comparable with other forms of salvage treatment.