Therapeutic dose and long-term efficacy of high-intensity focused ultrasound ablation for different types of uterine fibroids based on signal intensity on T2-weighted MR images

Abstract

Objective

To investigate the therapeutic dose and long-term efficacy of high-intensity focused ultrasound (HIFU) ablation for different types of uterine fibroids based on signal intensity on T2-weighted MR images (T2WI).

Materials and methods

Four hundred and one patients with a solitary uterine fibroid treated with HIFU were classified into four groups consisting of extremely hypointense, hypointense, isointense and hyperintense fibroids. Each group was further classified into two subtypes: homogeneous and heterogeneous, based on signal homogeneity of fibroids. The therapeutic dose and long-term follow-up results were compared.

Results

There were significant differences in treatment time, sonication time, treatment intensity, total treatment dosage, treatment efficiency, energy-efficiency factor (EEF) and non-perfused volume (NPV) ratio among the four groups (p<.05). The average NPV ratio achieved in patients with extremely hypointense, hypointense, isointense and hyperintense fibroids was 75.2 ± 14.6%, 71.1 ± 15.6%, 68.2 ± 17.3% and 67.8 ± 16.6%, respectively; the re-intervention rates at 36 months after HIFU were 8.4%, 10.3%, 12.5% and 6.1%, respectively. Sonication time, treatment intensity and total energy for heterogeneous fibroids were greater than that for homogeneous fibroids in patients with extremely hypointense fibroids (p<.05). The treatment time for heterogeneous fibroids was significantly longer than that for homogeneous fibroids in patients with isointense fibroids (p<.05). Multivariate ordered logistic regression analysis showed that the ablation volume of fibroids and treatment time were related to NPV ratio (p<.05).

Conclusion

Every group of patients obtained satisfactory long-term results. Hyperintense fibroids are difficult to treat by HIFU. Heterogeneous fibroids are more difficult to treat with HIFU than homogeneity fibroids.

Keywords:

• High-intensity focused ultrasound ablation
• uterine fibroids
• T2-weighted image
• therapeutic dose
• long-term efficacy
• re-intervention rate

Disclosure statement

Lian Zhang is a senior consultant to Chongqing Haifu. The other authors have no conflicts of interest to declare.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.