Feasibility of high-intensity–focused ultrasound (HIFU) for treatment of polycystic ovarian syndrome: potential for noninvasive treatment

Abstract

Purpose Polycystic ovarian syndrome (PCOS) affects 5-10 % of females in the child bearing period and is a common cause of infertility in this population. Surgical treatment is indicated for patients resistant to medical management. We investigate the feasibility of using HIFU as a non-invasive treatment of PCOS. Materials and Methods Ex-vivo canine ovaries fixed in gelatin were held in degassed water in front of an integrated 3.5 MHz dual mode ultrasound array (DMUA) system fenestrated to allow simultaneous use of a diagnostic transducer. DMUAs are transducers capable of imaging and treating with HIFU simultaneously using the same elements. Synthetic aperture (SA) and single transmit focus (STF) imaging were used to guide the treatment and HIFU shots (about 9-11 kW/cm 2 , 2 sec exposure time) were done at 6-7 mm depth. Ovaries were then sectioned and photographed to inspect the resultant damage. Results Echogenic changes were observed on imaging at the focal spot. Localized damage (~8×5 mm) was detected at the cortico-medullary interface; corresponding to the site of the echogenic changes. The ovarian surface was smooth and intact. SA imaging clearly showed the anatomical details of the ovaries. Conclusion We report the first use of DMUAs for potential treatment of PCOS by HIFU. Results demonstrate the feasibility of inducing thermal damage in ovaries without significant damage to the ovarian surface. This could potentially reduce the incidence of post-operative pelvic adhesions. Further, it should be possible to apply HIFU through a transvaginal probe, thus eliminating the risk associated with laparoscopy. SA imaging provided high resolution imaging that can guide the treatment. Further research is still needed to refine the exposure parameters and provide histological characterization of the HIFU induced damage.