Experimental studies of using of split beam transducer for prostate cancer therapy in comparison to single beam transducer

A "split beam" transducer arrangement was adapted for the existing benign prostatic hyperplasia (BPH) high intensity focused ultrasound (HIFU) treatment device, Sonablate-200/sup TM/ (manufactured by Focus Surgery Inc., Indianapolis, IN) for the treatment of localized prostate cancer. In the split beam configuration the HIFU beam is divided into several beams to create a larger treatment volume per ultrasound exposure which can reduce the overall treatment time. The objective of current study was to compare the necrosis volume and temperature patterns produced from "single beam" and "split beam" operating configurations. Experiments were performed on different test objects including Mylar strip, plexiglass, turkey breast tissue (in-vitro) and in vivo dog prostates. The results showed that the split beam configuration created larger lesion volume for the same exposure time while keeping the temperature near the rectal wall at the safe levels. Thus split beam transducer (SET) configuration should be effective and efficient in clinical application for the prostate cancer treatment.