MP12-01 INTRAOPERATIVE ADJUSTMENT OF TREATMENT PLAN AND TISSUE CHANGE MONITORING OF THE PROSTATE HAVE POTENTIAL FOR IMPROVING ONCOLOGICAL OUTCOMES IN THE PATIENTS WITH LOCALIZED PROSTATE CANCER TREATED WITH ULTRASOUND-GUIDED HIGH INTENSITY FOCUSED ULTRASOUND

Abstract

INTRODUCTION AND OBJECTIVES: High intensity focused ultrasound (HIFU) is an extracorporeal ablative technology. Recent literature suggested that intraoperative adjustment of treatment plan is necessary for precise treatment because prostatic swelling and intraprostatic targeted tissue shifts occur intraoperatively. The objective of this study is to evaluate the usefulness of intraoperative adjustment of treatment plan and tissue change monitoring of the prostate for improving oncological outcomes in the patients with localized prostate cancer treated with ultrasoundguided HIFU. METHODS: In transrectal HIFU device Sonablate (SonaCare Medical, IN, USA), Sonablate 200 (SB200) from 1999 to 2000, the Sonablate 500 (SB500) from 2000 to 2005, the Sonablate 500 version 4 (V4) from 2005 to 2008, and the Sonablate 500 TCM (TCM) from 2008, were used for the treatment and have been developed. Since V4, intraoperative adjustment of treatment plan could be used. Since TCM, intraoperative tissue change monitoring of the prostate could be used. The oncological outcomes were analyzed in the patients with localized prostate cancer treated with HIFU in 3 groups of treatment device (SB200/500, V4, and TCM). Biochemical failure was defined according to the Phoenix ASTRO definition. RESULTS: A total of 937 patients were included in this study. The 5-year biochemical disease free survival rate (BDFR) in the patients treated with S200/500 (n1⁄4412), V4 (n1⁄4250), and TCM (n1⁄4275) were 49%, 61%, and 75%, respectively (p<0.0001) (Figure). BDFR in the low-, intermediate-, and high-risk patients treated with SB200/500 at 5 and 10 years were 66% and 47%, 39% and 57%, and 42% and 23%, respectively. The BDFR in the low-, intermediate-, and high-risk patients treated with V4 at 5 years were 78%, 65%, and 46%, respectively. The BDFR in the low-, intermediate-, and high-risk patients treated with TCM at 5 years were 92%, 79%, and 65%, respectively. CONCLUSIONS: Intraoperative adjustment of treatment plan and tissue change monitoring of the prostate have potential for improving oncological outcomes of localized prostate cancer treated with ultrasound-guided HIFU. Source of Funding: none