Thyroid Nodule Ablation

The incidence of thyroid nodules continues to rise each year worldwide. Currently, it is estimated that 20–76% of adults have one or more thyroid nodules. Most thyroid nodules are benign, requiring no treatment. The growth of benign nodules can result in compression of the surrounding anatomical structures, such as the trachea, esophagus, and neck, requiring surgery. The current guideline of the American Thyroid Association suggest that two effective and relatively safe definitive treatment options for toxic AFTN are radioactive iodine (RAI) therapy and surgery. However, a small number of these patients develop hyperthyroidism, which can adversely affect the cardiovascular and skeletal systems. Some of these surgeries are high risk and carry several complications, like Hypocalcaemia, Laryngeal nerve injury, Hematoma, Hypothyroidism in some patients needing life-long thyroid hormone replacement. Also, elderly patients or individuals with dysfunctional immune systems are not considered as ideal candidates for surgery. It’s associated with a visible scar associated with the surgical procedure. Other treatment options include Ablation which could be laser, Microwave or Radiofrequency based and High Intensity focused Ultrasound therapy (HIFU).  In this context, we would discuss about Radiofrequency and Microwave ablation of benign Thyroid Nodules.

1. Donangelo, G.D. Braunstein, Update on subclinical hyperthyroidism, Am. Fam Physician 83 (2011).

Few of the common indications are listed below:

Indications:

• Benign thyroid nodules
  • Symptomatic
  • Cosmetic
• Benign diagnosis on at least two US-guided fine-needle aspirations (FNA) or core needle biopsy (CNB)
• Single benign diagnosis on FNA or CNB is sufficient:
  • When the nodule has US features highly specific for benignity
  • Autonomously functioning thyroid nodule (AFTN).

Work up:

Pre-procedure there is a need to have few investigations performed based on the presentation:

• Routine laboratory tests
• Thyroid function test
• Complete blood cell count
• Blood coagulation test
• US:
• CT/MRI for large goiters: Retrosternal extension
• Pertechnate or I¹³¹ scan: For AFTN

Absolute Contraindications:

• Lack of safe access
• Uncorrectable coagulation parameters

Procedure:

This procedure is generally performed as a day case procedure. This performed under local anesthesia, with no need for sedation in majority of cases. Based on the location of the nodule, the access site is decided and small nick is made for the needle to enter. Under ultrasound guidance, the needle is directed into the nodule and based on the machine settings, ablation is performed. The needle is repositioned and ablation is repeated until the whole nodule is covered. Once the procedure is complete, the needle is removed and hemostasis is achieved by manual compression. On average, the procedure time is about 20- 30 minutes. Sterile dressing is applied and if necessary ice packs are placed over the ablation site for comfort.