Purpose: The aim of this study was to evaluate the feasibility, safety and efficacy of ultrasound-guided percutaneous microwave (MW) ablation for solitary T1N0M0 papillary thyroid microcarcinoma.
Materials and methods: A total of 21 patients (six men and 15 women; age range, 29-81 years; mean, 52.1 ± 13.6 years) with 21 nodules of pathologically proven solitary papillary carcinoma 3.7 to 10.0 mm in diameter without clinically apparent lymph node, or distant metastasis at diagnosis (T1N0M0) were treated with MW ablation in our department. Microwaves were emitted at 40 W for 400 s and prolonged as necessary to attain confluent ablation zones. All patients were treated with levothyroxine after MW ablation to maintain thyroid stimulating hormone (TSH) levels below 0.1 mU/L. Follow-up consisted of ultrasound in 21 patients, biopsy in five patients, and surgical treatment in three patients.
Results: Four patients complained of hoarseness immediately after the MW ablation procedure, and all of them recovered within 3 months spontaneously. All tumours were completely ablated at a single session and no serious or permanent complications occurred. No recurrence at the treatment site and no distant metastases were detected, with a mean follow-up of 11 months. Histological examination showed no evidence of a tumour in the treated lesions in eight patients. Follow-up ultrasound examinations showed disappearance of previously detected colour Doppler flow, as well as mass shrinkage, or both.
Conclusion: During the short-term follow-up period, ultrasound-guided percutaneous MW ablation appears to be a safe and effective technique for solitary T1N0M0 papillary thyroid microcarcinoma.