Ultrasound-guided percutaneous microwave ablation of benign thyroid nodules: experimental and clinical studies

Abstract

Purpose: To obtain the treatment parameters of internally cooled microwave antenna and to evaluate the feasibility of ultrasound-guided percutaneous microwave ablation (MWA) for benign thyroid nodules. Materials and methods: MWAs were performed by microwave antenna (16G) in ex vivo porcine liver. The lesion diameters achieved in different groups (20, 25, and 30 W for 3, 5, 7, 10, and 12 min) were compared. The clinical study was approved by the ethics committee. Written informed consent was obtained from all patients. MWA was performed in 11 patients (male to female ratioZ1:10; mean age, 50G7 years) with 11 benign thyroid nodules. Ultrasound scan, laboratory data, and clinical symptoms were evaluated before and 1 day and 1, 3, 6, 9, and 12 months after the procedure. Results: In ex vivo study, the ablation lesion at 30 W 12 min tended to have appropriate scope and spherical shape. In clinical study, the follow-up periods ranged from 1 to 9 months. At the last followup, the largest diameter decreased from 2.9G1.0 (range, 1.6-4.1) to 1.9G0.7 (range, 0.4-3.0) cm (P!0.01), and the volume decreased from 5.30G4.88 (range, 0.89-14.81) to 2.40G2.06 (range, 0.02-6.35) ml (P!0.01). The volume reduction ratio was 45. 99G29.90 (range, 10.56-98.15) %. The cosmetic grading score was reduced from 3.20G0.79 to 2.30G0.95 (P!0.05). One patient experienced temporary nerve palsy and was recovered within 2 months after treatment. Conclusion: The internally cooled microwave antenna can yield ideal ablation lesions, and ultrasoundguided percutaneous MWA is a feasible technique for benign thyroid nodules.

Image-guided thermal ablation of benign thyroid nodules

“…Nevertheless, only a few studies considering MWA efficacy in the treatment of benign solid thyroid nodules are available. In these studies, at the post-treatment follow-up (from 1 to 12 months), nodule volume reduction ranged from 45 to 65 % [76,77,81,82]. Feng et al reported an improvement of symptoms and cosmetic score [77].…”

“…In these studies, at the post-treatment follow-up (from 1 to 12 months), nodule volume reduction ranged from 45 to 65 % [76,77,81,82]. Feng et al reported an improvement of symptoms and cosmetic score [77]. In a recent study, 30 patients with a total of 34 benign thyroid nodules underwent MWA.…”

“…A mild sensation of heat in the neck was experienced by most of the patients, but no one stopped the treatment. Slight fever was found in three patients, but lasted only one day [77]. 3-9 % of patients complained of voice changes, all recovering spontaneously within 3 months; in one case, treatment with corticosteroid was necessary [76,77].…”

“…3-9 % of patients complained of voice changes, all recovering spontaneously within 3 months; in one case, treatment with corticosteroid was necessary [76,77]. Hemorrhage was reported in nearly 40 % of cases [77].…”

“…The therapy continues until the whole nodule becomes hyperechoic. At the end of the treatment, the patient remains under observation for 30 min, with compression of the neck to prevent hematoma formation [76,77].…”