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.
- Donangelo, G.D. Braunstein, Update on subclinical hyperthyroidism, Am. Fam Physician 83 (2011).
Few of the common indications are listed below:
- Benign thyroid nodules
- 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).
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
- CT/MRI for large goiters: Retrosternal extension
- Pertechnate or I131 scan: For AFTN
- Lack of safe access
- Uncorrectable coagulation parameters
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.
- Observed for 30–60 min for any discomfort or complications.
- Antibiotic and analgesia.
- Pressure dressing if applied removed after 4 hours.
- Patient encouraged to take oral fluids after 4 hours.
- Soft diet-6 hours
- Regular diet-12 hours
- Check Ultrasound (If necessary).
- To check for hematoma and other complications.
- Voice change
- Skin burn
- Nerve injury
- Nodule rupture
- Performed at 1, 6 and 12 months after treatment
- Once a year there after.
- Thyroid Function tests:
- After 3 months
- Approximately 33% of nodules require 2–6 rounds of ablation for complete treatment.
- Currently, 3–6 months post-treatment is recommended as the optimal time to supplement the ablation of residual tissues.
What is a Thyroid nodule ablation?
A non-surgical treatment procedure that can reduce the size of thyroid nodules and restore thyroid function. This can be heat based or Laser based.
What is the difference between Radiofrequency and Microwave ablation of Thyroid nodules?
Not much differences in the outcomes. They differ in the energy settings and times.
What type of Thyroid nodules can be treated by ablation?
As discussed above these procedures are highly proven for nodules which are benign, symptomatic and for cosmetic reasons.
What about malignant Thyroid nodules?
There is some evidence to suggest the role of ablation in malignant nodules. However, please refer to your local physician and specialist for further details.
Can this procedure be applied to any other clinical conditions?
Some patients might have few residual nodes which demonstrate malignant potential after surgical exploration and it might be riskier redoing the surgery. Ablation of the nodules in this scenarios have demonstrated a favorable outcome.
Is it painful?
Most of these procedures are performed with local anesthesia. Very few cases need sedation.
How long does the procedure take?
Approximately 20 – 30 min.
Do I need pain medications after the procedure?
Mild analgesics and Ice packs are recommended for discomfort
Do I need to stop any of my medications prior to the procedure?
This depends on the type of medications that you are. Some of the anticoagulants have to be stopped prior to the procedure. Please refer to your local hospital guidelines where th eprocedur eis beign performed.
What about the follow up?
Ultrasound of the neck is recommended at 1, 6 and 12 months to assess the size of the nodule. You expect to see a reduction in the volume of the nodule.
Should I worry if the size of the nodule is increasing after ablation?
During follow up Ultrasound, you might see slight increase in the volume mostly seen at 1 month after the ablation. This could be due to inflammatory changes from the ablation. This should not be of immediate concern. If the further follow scans demonstrate increase in size or vascularity, it means that there might be a residual area of the nodule which might need additional ablation. This differs form case to case. Please refer to your physician for further details.
How many times can an ablation be performed?
No evidence to suggest of any complications with increased number of ablations as long as they are performed safely.
Does this preclude me from having surgery in the future?
No. This is performed to avoid surgery. If surgery is needed or warranted, ablation should not be an interference.