Thyroid nodules may be cystic, colloid, hyperplastic, adenomatous, or cancerous. Most are benign and often asymptomatic. They may be single (solitary nodule) or multiple (multinodular goitre). Some thyroid nodules produce thyroxine or triiodothyronine and cause thyrotoxicosis. These are called hyperfunctioning or toxic thyroid nodules.
Benign thyroid nodules may need treatment if they are symptomatic or causing cosmetic problems. Conventional treatment includes surgery. Less invasive alternatives to surgery include ethanol ablation, percutaneous laser ablation, high intensity focused ultrasound ablation and radiofrequency ablation.
Ultrasound-guided percutaneous microwave ablation for symptomatic benign thyroid nodules is a minimally invasive procedure done in an outpatient setting using local anaesthesia. The aim is to reduce symptoms and improve cosmetic appearance by making the nodule smaller while preserving thyroid function and with fewer complications than surgery.
The patient is placed in the supine position with moderate neck extension. A microwave antenna is inserted into the nodule using ultrasound guidance to visualise the electrode during the procedure. Once in position, the microwave antenna is activated to heat and destroy the tissue by coagulative necrosis. The antenna may be repositioned to ensure that most of the nodule is ablated.