Endocrine Abstracts

The aim of the study was to evaluate the safety, feasibility and efficacy of HIFU (High Insensity Focused Ultrasound) for the destruction of thyroid nodules in patients who are indicated for thyroid surgery.

Material and methods: 13 patients were treated by a HIFU device 2 weeks before thyroidectomy for euthyroid multinodular goiter. Ultrasound (US) examination was performed before and at 3, 8 and 15 days post treatment. Free T3, T4, TSH, thyroglobulin were measured before and after HIFU treatment. Only one thyroid nodule per patient was targeted. The included nodules were solid or mixed, with mean diameter ≥8 mm, located at least at 3 mm apart from the trachea, the esophagus, the carotid artery and the skin as evidenced by ultrasonography. Thyroidectomy was performed at 2 weeks followed by histopathological examination.

Results: The treatment was well tolerated, but became uncomfortable as the energy was increased. Subsequently the last patients received a local anesthesia. A superficial and reversible skin blister on patient 8th was observed. Design of treatment head was subsquently modified to eliminate such risk. Post HIFU US examination showed changes in echogenicity, a decrease in volume and vascularization at power Doppler examination in 10, 1 and 3 cases respectively. Thyroglobulin level increased in 1 case. Macroscopic and histological lesions were observed, and were precisely located in the targeted nodule without affect to the neighboring structures. The type of lesions in the treated nodule were central thrombosis in 1 case, diffuse lesion with cavitation, coagulative necrosis, haemorrhage and disappearance of the nuclei.

Conclusion: This study confirmed the feasibility and safety of the HIFU procedure. No serious adverse event was observed. The histological lesions were clearly visible in 10 cases. To obtain the complete nodule destruction in the next patients, the pulse energy must still be increased.