The study of feasibility of predicting the microwave ablation energy of uterine leiomyomas by three-dimensional power Doppler

Purpose: To evaluate the feasibility of predicting the microwave ablation (MVA) energy of uterine leiomyomas by three-dimensional power Doppler (3D-PD).

Methods and materials: 42 uterus leiomyomas in 41 patients who underwent ultrasound-guided Percutaneous Microwave Ablation (PMA) for treatment of uterus leiomyomas were studied from March 2014 to March 2015. Before PMA treatment, the uterus of patients was scanned by 3D-PD ultrasonography. Vascularization flow index (VFI) of 3D-PD of leiomyomas was calculated by virtual organ computer aided analysis (VOCAL) program. The average of three measurement was used for evaluating the richness of blood flow in the leiomyomas and the leiomyomas which mean diameter were more than 5 cm were treated with quantitative ablation energy of 50 w * 300 s and single antenna with 11 mm tip was used. Immediately after ablation the contrast-enhanced ultrasound (CEUS) was performed. The non-perfused volume (NPV) was measured as the volume of quantitative ablation. Relationship between VFI value of 3D-PD and microwave energy required per unit volume (EPV) was analyzed statistically.

Results: 42 leiomyomas (41 patients) were analyzed. Average VFI was 1.96 ± 1.63 and average ablation volume was (39.49 ± 22.68)cm³. Average EPV was 589.47 ± 399.36 (Jcm^-3). EPV was positively correlated with VFI value (r = 0.61, p = 0.00). When unit volume of leiomyoma was ablated, the leiomyoma with large VFI values needed higher microwave energy than that with small VFI values.

Conclusions: The more richness of blood vessel in the leiomyomas the more microwave energy was need for ablation unit volume. The value of VFI of uterus leiomyomas can be used to predict the PMA energy before ablation.