Ultrasound-guided percutaneous microwave ablation for uterine fibroids: mid-term local treatment efficiency and associated influencing factors

Abstract

Objective: To investigate the mid-term local treatment efficiency of ultrasound-guided percutaneous microwave ablation (MWA) for uterine fibroids (UFs) and the associated influencing factors. Methods: From July 2020 to October 2021, a total of 28 patients with 52 UFs who had undergone ultrasound-guided MWA were retrospectively included in this study. Pre-treatment clinical characteristics, conventional ultrasound and contrast-enhanced ultrasound (CEUS) features were analyzed to explore their correlation with volume reduction ratios (VRRs) of sufficient ablation (i.e. a VRR of at least 50% at the 3 month follow-up). The patients were assessed at 1-, 3-, 6 month follow-up after MWA treatment and the assessment included VRR, adverse events, uterine fibroid symptom (UFS) and quality of life (QoL) scores, and clinical symptoms. Results: The procedures of percutaneous MWA for UFs were tolerated well and no major complications occurred in all patients. At the 1-, 3-, 6 month follow-up, the median VRRs of UFs were 30.1%, 46.9%, and 65.8%, respectively. At the 3 month follow-up, 44.4% of fibroids obtained sufficient ablation while the remaining 55.6% obtained partial ablation (i.e. a VRR of <50%). Non-enhancing area during the early phase (i.e. within 30 s after injecting contrast agent) on pre-treatment CEUS was present in 22.2% UFs, which was associated with sufficient ablation at the 3 month follow-up (p < 0.05). In addition, the relevant clinical symptoms of all patients were alleviated or removed. The UFS and QoL score after MWA decreased significantly in comparison with those after MWA (p = 0.04 and p = 0.057, respectively), indicating a remarkable improvement of clinical symptom and QoL. Conclusion: Ultrasound-guided MWA is an effective and safe method to treat patients with UFs. Non-enhancing area during the early phase on pretreatment CEUS is associated with mid-term local treatment efficiency, which might be used to predict treatment outcome. Advances in knowledge: Non-enhancing area during the early phase on pretreatment CEUS is an important factor associated with mid-term local treatment efficiency. This is the first study finding that CEUS feature can be used as a marker for the prediction of mid-term local treatment response.