Optimized treatment parameter by computer simulation for high-intensity focused ultrasound treatment of uterine adenomyosis: Short-term and long-term results

Abstract

This study aimed to investigate the efficacy and safety of using optimized parameters obtained by computer simulation for ultrasound-guided high-intensity focused ultrasound (HIFU) treatment of uterine adenomyosis in comparison with conventional parameters. We retrospectively assessed a single-institution, prospective study that was registered at Clinical Research Information Service (CRiS) of Republic of Korea (KCT0003586). Sixty-six female participants (median age: 44 years) with focal uterine adenomyosis were prospectively enrolled. All participants were treated with a HIFU system by using treatment parameters either for treating uterine fibroids (Group A, first 20 participants) or obtained via computer simulation (Group B, later 46 participants). To assess the treatment efficacy of HIFU, qualitative indices, including the clinically effective dysmenorrhea improvement index (DII), were evaluated up to 3 years after treatment, whereas quantitative indices, such as the nonperfused volume ratio and adenomyosis volume shrinkage ratio (AVSR), on MRI were evaluated up to 3 months after treatment. Quantitative/qualitative indices were compared between Groups A and B by using generalized linear mixed effect model. A safety assessment was also performed. Results showed that clinically effective DII was more frequently observed in Group B than in Group A (odds ratio, 3.69; P = 0.025), and AVSR were higher in Group B than in Group A (least-squares means, 21.61; P = 0.001). However, two participants in Group B developed skin burns at the buttock and sciatic nerve pain and required treatment. In conclusion, parameters obtained by computer simulation were more effective than the conventional parameters for treating uterine adenomyosis by using HIFU in terms of clinically effective DII and AVSR. However, care should be taken because of the risk of adverse events.

Fig 1. Flow diagram of the study population.

MRI = magnetic resonance imaging, FSH = follicular stimulating hormone, HIFU = high-intensity focused ultrasound.

Fig 2. Examples of quantitative assessment of treatment efficacy on MR images of a 50-year-old woman.

(A, B) Pre-HIFU sagittal and axial T2-weighted images show an adenomyotic lesion at the posterior wall of the uterus. The volume of the adenomyotic lesion was calculated as 0.523 × length × width × height (lines) and was equal to 60.8 cm³. (C–F) Three-month follow-up images of the same participant. (C, D) Sagittal and axial T2-weighted images show shrinkage of the adenomyotic lesion. The adenomyosis volume was calculated as 12.0 cm³, and the adenomyosis volume shrinkage rate was 80.3%. (E, F) Contrast-enhanced T1-weighted images demonstrate nonperfused volume, which was equal to 8.3 cm³. The calculated nonperfused volume ratio in this participant was 69.1%.

Fig 3. A representative case of adenomyosis in a 50-year-old woman in group B.

(A) Sagittal T2-weighted image obtained at screening show a uterine adenomyosis (arrow) (5.7 cm × 5.1 cm × 4.0 cm) at the uterine posterior body. (B, C) One-month and three-month follow-up sagittal T2-weighted images, respectively. The volume of the adenomyosis (arrowheads) further shrunken, and the adenomyosis volume shrinkage ratios were 67.0% and 80.3%, respectively.

Fig 4. An adverse event after high-intensity focused ultrasound treatment.

Sagittal T2-weighted images (A, B, E) and contrast-enhanced T1-weighted images (C, D) of a 46-year-old woman with adenomyosis (arrowhead). (A) Before HIFU treatment. (B, C) Increased signal intensity and enhancement along the anterior wall of the upper rectum adjacent to the adenomyosis was detected in the immediate posttreatment images (arrows). Her symptoms improved after conservative management, and she was discharged. (D, E) At the 1-month follow-up, the signal intensity of the rectal wall was normalized (arrow). Note the shrinkage of the treated adenomyosis (arrowhead).