How do ablation techniques, such as Radiofrequency Ablation (RFA) or Microwave Ablation (MWA), and Transarterial Embolization (TAE) compare to surgery for treating benign thyroid disease?

Thermal Ablation and TAE Versus Surgery for Benign Thyroid Disease

For benign thyroid nodules causing symptoms or cosmetic concerns, thermal ablation (RFA/MWA) should be considered the first-line treatment over surgery, offering comparable efficacy with superior safety, preservation of thyroid function, and shorter recovery times. 1

Key Advantages of Thermal Ablation Over Surgery

Efficacy Outcomes

• Volume reduction with thermal ablation is substantial and clinically meaningful, achieving 44.6% to 70.9% volume reduction at 6-12 months follow-up, with maximum results by 6 months 2, 3
• Symptom resolution is excellent with thermal ablation: compressive symptoms resolved in 67% and improved in 33% of patients, with cosmetic concerns improving in all treated patients 2
• Surgery and thermal ablation both achieve significant nodule reduction, but thermal ablation avoids the permanence and risks of surgical resection 4

Safety Profile Comparison

• Complication rates strongly favor thermal ablation over surgery: 1.0-6.0% for thermal ablation versus 6.0-14.0% for surgery 3, 4
• Hypothyroidism is dramatically reduced with thermal ablation: 0% following thermal ablation versus 71.5% after surgery, eliminating the need for lifelong thyroid hormone replacement in most patients 4
• Thermal ablation preserves thyroid function when normal, with no impact on thyroid function tests in euthyroid patients 2, 3
• Major complications are rare with thermal ablation: transient hoarseness and hematoma are the most common issues, with no sustained complications reported 2, 3

Practical Clinical Advantages

• Hospitalization is significantly shorter: 2.1 days for thermal ablation versus 6.6 days for surgery 4
• Thermal ablation offers outpatient treatment capability, simple operation, short procedure time, no neck scar, and preservation of thyroid function without lifelong medication in most cases 1
• Residual nodule rates favor thermal ablation: 2.9% versus 11.9% for surgery 4

Comparison of RFA Versus TAE for Large Nodules

When to Choose TAE Over RFA

• For nodules exceeding 100 mL, TAE demonstrates superior efficacy over RFA, achieving 63.34% volume reduction versus 49.71% with RFA at 6 months 5
• TAE has a lower complication rate than RFA for large nodules: 5.26% versus 14.03%, with fewer instances of transient hoarseness and hematoma 5
• TAE provides greater improvements in symptom and cosmetic scores for larger nodules compared to RFA 5

When RFA Remains Preferred

• For nodules under 100 mL, RFA achieves better volume reduction than MWA at 6 months and later follow-up, with comparable safety profiles 6
• RFA is the established standard for most benign thyroid nodules, with extensive clinical experience and guideline support 1

Clinical Algorithm for Treatment Selection

Step 1: Confirm Benign Pathology

• All patients must undergo fine-needle aspiration biopsy (FNAB) before thermal ablation to confirm pathological diagnosis (strong recommendation, high-quality evidence) 1

Step 2: Assess Nodule Characteristics

• Nodule size and composition determine treatment approach: thermal ablation is appropriate for solid nodules or cystic nodules with ≥10% solid composition 7
• Measure baseline nodule volume and document symptoms: compressive symptoms (dysphagia, dyspnea, voice changes) and cosmetic concerns 2, 3

Step 3: Select Treatment Modality

• For nodules <100 mL with symptoms or cosmetic concerns: Choose RFA as first-line thermal ablation 2, 3, 6, 4
• For nodules >100 mL: Choose TAE over RFA for superior volume reduction and fewer complications 5
• Reserve surgery for: patients who refuse ablation, have contraindications to thermal ablation, or have persistently nondiagnostic cytology after repeat FNAB 8

Step 4: Technical Approach

• Use local anesthesia with 1-2% lidocaine, with transisthmic needle insertion approach preferred 1
• Employ hydrodissection technique to protect recurrent laryngeal nerve, trachea, esophagus, and major vessels (strong recommendation, high-quality evidence) 1
• Perform immediate post-ablation assessment with contrast-enhanced ultrasound (CEUS) to confirm complete ablation 1, 7

Step 5: Follow-Up Protocol

• Initial follow-up at 1 month, then at 3,6, and 12 months during the first year 1
• After 12 months, reassess benign nodules annually with ultrasound and symptom evaluation 1
• Monitor volume reduction rate (VRR) as the primary efficacy endpoint: VRR = [(Preoperative volume – Follow-up volume) × 100]/Preoperative volume 1

Critical Pitfalls to Avoid

• Do not proceed with thermal ablation without confirmed benign cytology: malignancy must be excluded via FNAB before considering ablation 1
• Do not use thermal ablation for nodules with suspicious or malignant features unless specific criteria for papillary thyroid microcarcinoma are met 1
• Do not overlook the need for adequate hydrodissection: this is essential to prevent nerve injury (strong recommendation, high-quality evidence) 1
• Do not assume surgery is necessary for large nodules: thermal ablation (particularly TAE for nodules >100 mL) offers effective minimally invasive alternatives 5, 4

When Surgery Remains Indicated

• Surgery should be reserved for: confirmed malignancy requiring total thyroidectomy, follicular neoplasia with indeterminate cytology, persistently nondiagnostic cytology after repeat FNAB, or patient preference for definitive surgical management 1, 8
• Compressive symptoms alone do not mandate surgery: thermal ablation effectively resolves compressive symptoms in 67-100% of patients 2, 3