Ultrasound-guided percutaneous microwave ablation for 755 benign breast lesions: a prospective multicenter study

Objectives To evaluate the clinical efficacy of microwave ablation (MWA) of benign breast lesions (BBLs) and compare the learning curves of international radiologists (IRs) and surgeons. Methods In total, 440 patients with 755 clinicopathologically confirmed BBLs from 5 centers were prospectively enrolled from February 2014 to July 2018. Technical success, complications, volume reduction ratio (VRR), palpability, and cosmetic satisfaction after ablation were analyzed. In addition, the ablation time (AT) and energy (AE) with the number of procedures were analyzed for learning curve evaluation. Results The mean maximum diameter was 1.7 ± 0.6 cm. The complete ablation rate reached 100%, including 45.8% lesions adjacent to the skin, pectoralis, or areola. After a median follow-up of 13.7 months, the 12-month VRR of all lesions was 97.9%, and that for 1.0- to 2.0-cm and ≥ 2.0-cm lesions was 98.6% and 96.9%, respectively. A total of 55.9% of BBLs became nonpalpable (palpable in 85.7% of cases before MWA) by both the clinician and patient. The cosmetic and minimally invasive satisfaction rates were good or excellent in 98.4% and 94.5% of patients, respectively. The median AT/cm 3 and AE/cm 3 decreased as experience increased. The AE/cm 3 of the IR with 5 years of experience was lower than that of the IR with 1 year of experience and the surgeons, while the AT/cm 3 of surgeons was comparable with that of the IR with 5 years of experience at relatively mature phase. Conclusions Ultrasound-guided percutaneous MWA is a valuable technique for the treatment of BBLs. Trial registration: ClinicalTrials.gov (NCT02860104) Key Points • Ultrasound-guided percutaneous microwave ablation has the potential to become a valuable technique for the treatment of benign breast lesions. • A skilled interventional radiologist shows a rapid improvement in mastering the technique.