An image-guided high intensity focused ultrasound device for uterine fibroids treatment.
A high intensity focused ultrasound (HIFU) device was developed for treating uterine fibroid tumors. This prototype device enables image-guided therapy by aligning a commercially available abdominal ultrasound image probe to a vaginal HIFU transducer so the HIFU focus is in the image plane. The device was designed based on anatomical constraints of the female pelvic structures. HIFU was generated using a 3.5 MHz PZT-8 crystal, 25.4 mm in diameter, bonded to an aluminum lens. Computer simulations were performed to ensure that effective focusing was achievable at a fixed focal depth of 40 mm. Transducer efficiency was empirically determined to be 58%, and the half pressure maximum focal dimensions were 11 mm in length and 1.2 mm in width. A water-filled latex condom surrounding the transducer provided acoustic coupling, a stand-off, and allowed water circulation for transducer cooling. In vitro experiments in a tissue-mimicking gel phantom and in turkey breast demonstrated ultrasound image-guided lesion formation, or tissue necrosis, at the focus due to HIFU induced thermal and cavitation effects. The HIFU treatment site appeared as a hyperechoic spot on the ultrasound image at intensities above 1250 W/cm2. The results of in vitro experiments and in vivo ergonomic testing in six human volunteers indicated that the device has the potential of providing a nonsurgical approach for uterine fibroid treatment. Future in vivo studies in large animal models and fibroids patients are planned.
Chan
Arthur H
AH
Department of Bioengineering, University of Washington, Seattle, Washington 98105, USA. ahchan@u.washington.edu
Fujimoto
Victor Y
VY
Moore
Donald E
DE
Martin
Roy W
RW
Vaezy
Shahram
S
D000328:Adult; D019412:Anatomy, Cross-Sectional; D000818:Animals; D001940:Breast / Q000528:radiation effects; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006804:Ergonomics / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007889:Leiomyoma / Q000000981:diagnostic imaging* / Q000628:therapy*; D008875:Middle Aged; D019047:Phantoms, Imaging; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D014159:Transducers; D014421:Turkey; D014464:Ultrasonic Therapy / Q000295:instrumentation* / Q000379:methods; D014463:Ultrasonography; D014594:Uterine Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy; D014599:Uterus / Q000033:anatomy & histology / Q000000981:diagnostic imaging