Risk Factors and Prediction Nomogram of Local Regeneration after Ultrasound-guided Microwave Ablation of Uterine Fibroids.

Study objective: To explore the risk factors associated with local regeneration of the treated uterine fibroids (UFs) after microwave ablation (MWA) and to develop a nomogram model for predicting the risk of local regeneration.

Design: Retrospective study.

Setting: The Eighth Affiliated Hospital of Sun Yat-Sen University.

Patients: Patients with UFs who underwent MWA at our hospital between October 2020 and April 2023 were included.

Intervention: MWA was used for the treatment of UFs.

Measurements and main results: A total of 47 patients with 68 fibroids were included into this study. Over a median follow-up of 13 months (interquartile range, 8-22 months), local regeneration occurred in 11 UFs. The clinical and imaging characteristics of these patients were recorded and compared. Risk factors for local regeneration were determined through univariate and multivariate Cox regression analysis. Multivariate analysis revealed that the fertility desires, larger size of UFs (≥95.3 cm³), and hyperenhancement of UFs on contrast-enhanced ultrasound were independent risk factors for local regeneration after MWA. A predictive nomogram was constructed to predict the local regeneration after MWA of UFs. The concordance index (C-index) (C-index, 0.924; internal validation C-index, 0.895) and the 1- and 2-year area under the curve values (0.962, 0.927) all indicated that the nomogram had good predictive performance. Calibration and decision curve analysis curves further confirmed the model's accuracy and clinical utility.

Conclusion: Fertility desires, larger size of UFs, and hyperenhancement on contrast-enhanced ultrasound were independent predictors of UFs local regeneration after MWA in our study. The nomogram constructed based on the abovementioned independent risk factors may help predict which UFs will develop local regeneration after MWA.