MR-guided high intensity focused ultrasound thermoablation under temperature mapping monitoring for the treatment of uterine fibroids

Objective: To assess the feasibility and effectiveness of MR-guided high intensity focused ultrasound (MRgHIFU) thermoablation under temperature mapping monitoring for the treatment of uterine fibroids. Methods: MRgHIFU was carried out in 52 patients with a total of 61 uterine fibroids. The mean age was (39.6 ± 7.3) years (ranged between 23-56 years), and the average diameter of the fibroids was(6.1 ± 2.1) cm (ranged between 1.2-10.7 cm). This procedure was accomplished by a JM-HIFU system (Mode JM15100, Chongqing Haifu Technology Co., Ltd., China), in combination with a 1.5-Tesla MRI system (Avanto TIM, Siemens, Germany), which provided real-time guidance and temperature mapping. Contrast-enhanced MR imaging was performed both immediately and three months after MRgHIFU treatment in order to evaluate the efficacy of thermal ablation. The treatment time and adverse events were recorded. The percentage of ablation volume was calculated after the procedure. The changes in the size of the uterine fibroid and in the clinical symptoms three months after the procedure were evaluated. Results: The mean fibroid volume for each case before and three months after MRgHIFU treatment was (113.3 ± 87.7) cm3 and (58.1 ± 45.0) cm3 respectively(P < 0.05), and each fibroid volume was decreased by (48.7 ± 16.4)% with a range of (19-84)%. An average of (78.8 ± 18.8)% (ranged between 51-100%) of the fibroid volume was ablated, and the fractional ablation was defined as non-perfused volume divided by the fibroid volume measured immediately after HIFU treatment. The mean treatment time for completing the ablation of (83.3 ± 71.7) cm3 (ranged between 7.7-282.9 cm3) of fibroid volume was (19.8 ± 8.8) minutes. The mean energy of focused ultrasound delivered into the ablated fibroid tissue was (7.1 ± 6.7) J/mm3 (ranged between 0.9-32.1 J/mm3). The symptoms were relieved, the mean overall points decreased from (24.7 ± 4.8) to (16.7 ± 3.2) after therapy (P < 0.05). One patient experienced mild skin burn (small blisters), which subsided within two days. No other adverse events and complications were observed. Two patients got pregnant at three months after the treatment. Conclusion: MR-guided high intensity focused ultrasound treatment is a safe, effective and non-invasive technique for ablating uterine fibroids. A single thermoablation procedure is enough to make the most part,or even all, of the fibroid becoming coagulation necrosis and smaller in a short period. (authors)