Thyroid Nodules
A comprehensive guide
Benign thyroid nodules are a common clinical finding. Historically, surgery was the only definitive treatment when nodules caused symptoms. However, the development of minimally invasive techniques—such as radiofrequency ablation (RFA)—now offers effective alternatives for select patients.
How does IR diagnose nodules without surgery?
Interventional radiology (IR) provides several non-surgical, image-guided methods to evaluate and diagnose thyroid nodules:
1. Ultrasound-Guided Fine-Needle Aspiration (FNA) Biopsy: A thin needle is inserted into the thyroid nodule under real-time ultrasound guidance to extract a sample of cells. The sample is then analyzed microscopically to determine whether the nodule is benign or malignant. FNA is minimally invasive, safe, and widely used as a first-line diagnostic test.
2. Core Needle Biopsy: This procedure uses a slightly larger needle to obtain a small core of tissue, which can provide more detailed architectural information than FNA. It is particularly useful when FNA results are inconclusive.
3. 18F-FDG PET/CT: This imaging technique uses a radioactive tracer to highlight metabolically active tissue. In certain cases, PET/CT may help distinguish benign from malignant nodules and reduce the need for invasive procedures.
4. Additional Assessments
- Thyroid function tests are used to evaluate hormone levels and identify hyper- or hypothyroidism.
- Ultrasound imaging assesses the size, composition, and vascularity of the nodule.
- Active surveillance may be appropriate for small, benign nodules that are not causing symptoms. These nodules are monitored over time using periodic imaging and clinical evaluation.
Are ablation & embolization better than surgery?
Surgery (such as hemithyroidectomy or total thyroidectomy) remains a standard treatment for thyroid nodules, especially when malignancy is suspected. However, for patients with benign nodules, radiofrequency ablation and less commonly embolization are viable non-surgical alternatives.
Thermal Ablation: Uses targeted heat (most commonly via RFA) to reduce nodule volume without removing the thyroid gland. It is performed under ultrasound guidance using a thin probe and does not require incisions or general anesthesia.
Thyroid Artery Embolization: Involves occluding the blood supply to a thyroid nodule using catheter-based techniques. It is rarely used for thyroid nodules, except in select cases such as large, vascular goiters or in patients unsuitable for surgery.
Benefits of Ablation:
- Preserves thyroid function
- Leaves no visible scar
- Performed on an outpatient basis with minimal recovery time
- Low risk of complications
When Surgery May Be Preferred:
- Nodules with confirmed or suspected malignancy
- Large, compressive goiters causing airway or esophageal obstruction
- Multinodular or recurrent disease requiring comprehensive intervention
What’s the difference between ablation and embolization?
Patients exploring non-surgical treatment options for thyroid nodules may come across two minimally invasive techniques: radiofrequency ablation and thyroid artery embolization. While both procedures aim to reduce the size and symptoms of nodules without surgery, they differ significantly in their mechanisms, approach, and clinical applications, especially when it comes to thyroid care.
Radiofrequency Ablation
Mechanism:
Thermal ablation, most commonly performed using radiofrequency ablation (RFA), works by delivering controlled heat directly into the thyroid nodule. The heat induces coagulative necrosis, causing the nodule to shrink over time.
Procedure:
- Performed under local anesthesia
- Uses a thin needle electrode inserted through the skin and guided by real-time ultrasound
- Outpatient setting; typically completed within one hour
- No incisions or stitches required
Outcomes:
- Significant and sustained reduction in nodule volume (typically 50–90% within 6 to 12 months)
- Preservation of surrounding thyroid tissue and gland function
- No visible scarring
- Low complication rates, with voice changes and bleeding being rare
Thyroid Artery Embolization
Mechanism:
Embolization involves occluding the blood vessels that supply a thyroid nodule or an enlarged thyroid gland. This is achieved by injecting small particles through a catheter, leading to ischemia and subsequent reduction in nodule size.
Procedure:
- Performed by an interventional radiologist in a hospital or advanced imaging suite
- Requires arterial access via the groin or wrist
- Typically done under local anesthesia with sedation
- Procedure time and recovery are generally longer than for thermal ablation
Outcomes:
- May reduce vascularity and size of large goiters or nodules over time
- Currently lacks extensive long-term outcome data for routine use in benign thyroid nodules
- May cause transient post-procedural inflammation, pain, or glandular dysfunction
When is ablation recommended for nodules?
Radiofrequency ablation (RFA) is an established treatment option for select thyroid nodules. It is typically recommended in the following clinical scenarios:
1. Symptomatic benign nodules
Ablation is appropriate for nodules that are causing:
- Neck discomfort or tightness
- Difficulty swallowing
- Hoarseness due to pressure on nearby structures
Ablation is also considered for nodules that are large in size (generally >2.5–3 cm in diameter) with documented growth over time. In these cases, ablation offers a non-surgical alternative that relieves symptoms while preserving normal thyroid tissue and function.
2. Cosmetically concerning nodules
Even if a nodule is not causing physical symptoms, treatment may be considered when:
- The nodule is visibly prominent and impacts the patient's appearance
- Patients prefer removal for aesthetic reasons but wish to avoid surgery
Ablation is particularly well-suited for these cases, as it avoids scarring and offers excellent cosmetic outcomes with minimal downtime.
3. Autonomously functioning (hot) nodules
In cases of autonomously functioning thyroid nodules—nodules that produce excess thyroid hormone independently of the rest of the gland—ablation may be used to:
- Reduce hormone production
- Restore normal thyroid function
- Avoid or delay the need for radioactive iodine or surgery
This approach may be appropriate in selected patients with mild hyperthyroidism, especially if they are poor surgical candidates or wish to avoid radioactive therapy.
4. Patients unsuitable for surgery
Ablation is often considered for patients who:
- Are medically unfit for surgery due to comorbidities
- Prefer to avoid general anesthesia
- Are at higher risk for surgical complications
What does long-term monitoring look like following RFA?
Though ablation has a strong safety and efficacy profile, ongoing monitoring is essential to ensure optimal outcomes and detect any signs of recurrence or regrowth.
Follow-up schedule:
Initial post-procedure ultrasound: Typically 1 month after ablation to assess early response and rule out complications.
Subsequent ultrasounds: At 3 or 6 months, then at 12 months, and annually thereafter depending on the response and residual volume. Nodules are expected to reduce in volume gradually, with most shrinkage occurring in the first 6 to 12 months.
Thyroid function tests:
Baseline thyroid function is assessed prior to the procedure.
Follow-up blood tests may be done at 6–12 weeks and then periodically (especially if the patient has a functioning nodule or underlying thyroid disease).
In most patients, thyroid hormone levels remain stable after ablation.
Additional ablation sessions may be considered if:
- The nodule begins to regrow after initial reduction
- Symptoms or cosmetic concerns return
- New nodules develop in other areas of the gland
Patients are encouraged to report any new symptoms and continue routine imaging as recommended.
Choose RIVEA for advanced thyroid care
At RIVEA Vascular Institute, our Interventional Radiology department is led by our co-founder Dr. Arjun Reddy. A highly skilled and patient-focused Interventional Radiologist, Dr. Reddy has previously served as a consultant at AIG Hospitals and Apollo Hospitals, Jubilee Hills, Hyderabad. He specializes in minimally invasive procedures that offer faster recovery, fewer side effects, and no surgical scars. With years of experience in embolization techniques, he offers patients a safe, effective, and non-surgical path to thyroid health.