Clinical Study Of Precise Microwave Ablation For Benign Breast Tumors

Objective: To evaluate the imaging and clinical effects of microwave ablation(MWA)in the treatment of benign breast neoplasms,and to explore the imaging features of complete ablation of breast tumors and the influencing factors on microwave-induced accurate ablation of MWA.Methods: With the approval of the institutional ethics committee and informed consent in writing,47 patients with 52 core-biopsy-proved benign breast tumours(long diameter 7-32mm)assessed by using ultrasound(US)and contrast-enhanced ultrasound(CEUS)were prospectively recruited.US-guided MWA was performed under local anaesthesia.The patients were analysed and followed up with physical examination,ultrasound elastography and CEUS.Results: Forty-seven consecutive patients with 52 completely ablated tumours were enrolled.The MWA procedure with a mean duration of 74.3 s ± 26.5 was well accepted and tolerated in 49 cases except for three cases.Of 49 tumours with followup data,48(97.5%,95% confidence interval: 87.1%,99.9%)showed complete ablation assessed by using CEUS.Of these 52 tumour ablations in US,16 ablations were defined as concentric type,and 36 were defined as non-concentric type.Of these52 ablations,7 cases were defined as nonaccurate ablation with the largest margin >10 mm in US.The nonaccurate ablation rate in the training group(the first consecutive 30 cases,7/30)was significant higher than that(the last 22 cases,0/22)in the practiced group(p=0.016).Of 38 completely ablated cases(9mm<the longest diameter<20mm),the average largest margin in >70s group was significant larger than that in <70s group(p =0.019).The mean volume of the ablated tumours decreased significantly(p=0.005)during follow-up.The strain ratio 1-3 months after ablation was higher than that before ablation,and became low 6 months after ablation(p=0.022).No epidermal burn was observed in all cases with a mean distance of 7.5mm ±3.3 from the tumour to the skin.Conclusions: MWA is a safe and effective minimally invasive “patient-friendly”procedure with a very short duration for the treatment of benign breast tumours.Experience was important for accurate MWA in the treatment of benign breast tumour,and at least 30 cases training was recommended.Nevertheless,clinical trials are still required to validate our findings in the future.