Advantages of ablation over surgery include:
- Negligible risk of permanent hypothyroidism
- No visible scars
- Lower complication rates
- Shorter recovery times
- Improved quality of life related to thyroid health
- Cost reduction compared to operating room-based procedures
- Performance in day surgery/day hospital without the need for general anesthesia
When indicated
Thermal ablation for benign nodules is more suitable for patients with compressive and/or cosmetic disorders that can be clearly attributed to a single or dominant nodule. Patients with thyroid nodules that function autonomously and cause subclinical or manifest hyperthyroidism can also be successfully treated with ablative techniques. Since ablation does not allow for definitive diagnostic maneuvers (histological), a careful assessment of benignity must be made to minimize the risk of overlooking malignant lesions.
The criteria are:
- Benign cytology
- Very low or low ultrasound risk stratification for classified malignancy
Main Benefits
The benefits of ablative procedures include the reduction of nodule volume, improvement of compression symptoms and aesthetic discomfort, and the absence of scars and the need for lifelong thyroid hormone supplementation. Compared to surgery, additional benefits include less recovery time and a quicker return to normal daily activities. However, ablative techniques also have new and unique limitations compared to traditional surgical approaches or observation, and it is essential for the patient to understand these factors before consenting to thermal ablation.
How it Works:
MWA systems consist of a microwave generator, and internally cooled needles/antennas of 18 to 16 G caliber (very thin) are currently available. The active part of the microwave antenna can vary between 3-5 mm, and the entire needle is typically 10 cm long. The area is treated with very low watts (10 to 20w) and thin antennas (18-17 G). Ablation is performed sequentially (moving shot) in periods of 5-10 seconds to treat the entire nodule and continues until the nodule shows appropriate changes on ultrasound indicating complete ablation. For large nodules, a thicker antenna, 16 G caliber, can be used with a “stationary technique” in multiple steps: the needle is inserted into the area to be treated, with adequate higher power (20-40 W) according to the currently available algorithm for each generator, waiting for the predictable necrotic area production up to 3 cm in diameter. This technique avoids the insertion of multiple antennas, which increases the risk of complications.
Treatment Procedure
The treatment is performed under local anesthesia, and the most common approach for local anesthesia injection uses a small-caliber needle (27-30 gauge) to inject subcutaneous anesthesia into the neck through the midline. This is directed towards the thyroid capsule and advanced between the capsule and the muscle to evenly spread the anesthetic over the thyroid capsule.
After the ablation of the thyroid nodule, but not frequently, mild and tolerable pain in the treated area and neck is expected. In addition, some swelling of the nodule and surrounding tissues is common during the first week. These symptoms usually peak in the first 3-5 days following the procedure and then subside.
Compared to surgical management, it is important to educate patients that the benefits of ablation are not immediate but mature over months. The reduction in nodule size after ablation is most noticeable from the first to the third month. Despite this, patients often report significant symptom improvement as early as the first month.
Long-term follow-up with clinical, laboratory, and ultrasound evaluation is recommended after the ablation of thyroid nodules at 1, 3, 6, 12 months, and then annually.
