Treatment of uterine fibroid tumors in a nude mouse model using high-intensity focused ultrasound

Objective: The purpose of this study was to investigate the potential efficacy of high-intensity focused ultrasound for the treatment of uterine fibroid tumors in a nude mouse model. Study Design: A total of 60 female athymic nude mice were inoculated subcutaneously with 3 to 5 × 106 ELT-3 cells, a uterine fibroid tumor cell line. Tumor size was monitored with transcutaneous caliper measurements. The high-intensity focused ultrasound probe was a concave, single-element, high-power transducer that operated at a frequency of 3.5 MHz. The tumors were treated for 30 to 60 seconds using a high-intensity focused ultrasonic intensity of 2000 W/cm2, depending on the tumor size. Results: A single high-intensity focused ultrasonic treatment resulted in an average reduction in tumor volume of 91% within 1 month of the treatment. Histologic analysis of tumors treated with high-intensity focused ultrasound showed coagulation necrosis and nuclear fragmentation of tumor cells. Conclusion: High-intensity focused ultrasound effectively reduced uterine fibroid tumor size in a nude mouse model. Further studies are needed to assess the in situ response of uterine fibroids to high-intensity focused ultrasonic treatment. (Am J Obstet Gynecol 2000;183:6-11.)