The feasibility and safety of high‐intensity focused ultrasound as salvage therapy for recurrent prostate cancer following external beam radiotherapy

Abstract

To investigate the use of minimally invasive high-intensity focused ultrasound (HIFU) as a salvage therapy in men with localized prostate cancer recurrence following external beam radiotherapy (EBRT). A review of 31 cases treated using the Sonablate 500 HIFU device, between 1 February 2005 and 15 May 2007, was carried out. All men had presumed organ-confined, histologically confirmed recurrent prostate adenocarcinoma following EBRT. The mean (range) age was 65 (57-80) years with a mean preoperative PSA level of 7.73 (0.20-20) ng/mL. The patients were followed for a mean (range) of 7.4 (3-24) months. Side-effects included stricture or intervention for necrotic tissue in 11 of the 31 patients (36%), urinary tract infection or dysuria syndrome in eight (26%), and urinary incontinence in two (7%). Recto-urethral fistula occurred in two men, although one was due to patient movement due to inadequate anaesthesia, so the 'true' rate is 3%. Half of the patients had PSA levels of <0.2 ng/mL at the last follow-up. Three patients had metastatic disease whilst another two had only local, histologically confirmed, failure. A further four patients had evidence of biochemical failure only. Overall, 71% had no evidence of disease following salvage HIFU. Salvage HIFU is a minimally invasive daycase procedure that can achieve low PSA nadirs and good cancer control in the short term, with comparable morbidity to other forms of salvage treatment. The issue of accurate staging at the time of recurrence is still problematic, as a proportion of these men will harbour microscopic metastases undetected by conventional staging investigations.