What is the preferred treatment approach for benign thyroid disease: Thyroid Radiofrequency Ablation (RFA) or Microwave Ablation (MWA) versus surgery?

Thyroid RFA/MWA vs Surgery for Benign Thyroid Disease

For symptomatic benign thyroid nodules, thermal ablation (RFA or MWA) should be considered as a first-line alternative to surgery in appropriately selected patients, particularly those with solid nodules ≥2 cm causing compressive symptoms, cosmetic concerns, or anxiety, as both techniques achieve approximately 50-80% volume reduction with significantly lower morbidity than surgery. 1, 2, 3

Primary Treatment Selection Algorithm

Thermal Ablation is Preferred For:

• Solid or predominantly solid benign nodules (≥10% solid component) with maximal diameter ≥2 cm that are enlarging gradually 1
• Nodules causing clinical symptoms including compression, cosmetic deformity, dysphagia, or dysphonia 1, 3
• Recurrent nodules after chemical ablation 1
• Patients with significant surgical comorbidities or those refusing surgery 1, 2

The 2025 Chinese guidelines specifically recommend thermal ablation as an optional treatment with strong recommendation and moderate-quality evidence for these indications 1. Real-world effectiveness data demonstrates 78% patient-reported symptom resolution with RFA, with mean volume reduction of 52-59% in those achieving symptom relief 3.

Chemical Ablation (Ethanol) is Preferred For:

• Cysts or predominantly cystic nodules with <10% solid composition 1
• Relapsing thyroid cysts, where ethanol injection should be considered therapy of choice 2

Surgery Remains Indicated For:

• Autonomously functioning thyroid nodules (though radioactive iodine is actually preferred first-line for these) 2, 4
• Nodules with indeterminate or suspicious cytology requiring definitive histologic diagnosis 1
• Patients preferring definitive single-intervention treatment 1

RFA vs MWA: Comparative Efficacy

RFA demonstrates superior volume reduction compared to MWA at 6 months and beyond, though both are safe and effective. 5, 6

Volume Reduction Outcomes:

• RFA achieves significantly better maximal diameter reduction ratio (MDRR) and volume reduction ratio (VRR) than MWA at 6-month and later follow-up 5
• A 2024 randomized controlled trial showed MWA was noninferior to RFA for 6-month (mean difference -5.6%) and 2-year (mean difference -2.4%) VRR, with comparable technique efficacy (91% vs 86%) 6
• Both techniques achieve approximately 50% volume reduction in a single session 2

Safety Profile:

• Major complication rates are comparable: 4.78% for RFA vs 6.63% for MWA, with no statistically significant difference 5
• Voice change is the most common major complication, occurring in 6.6% with MWA vs 1.3% with RFA (not statistically significant, but trend toward higher risk with MWA) 6
• Surgical complications (laryngeal nerve palsy, hypoparathyroidism) occur in <1-2% with expert thyroid surgery 1, 7

The evidence suggests RFA may have a slight edge in efficacy and possibly safety, though the 2024 RCT showed noninferiority for MWA 5, 6. Given the larger body of evidence and recommendations in guidelines, RFA should be considered the first-line thermal ablation technique when both are available. 1, 2

Critical Patient Selection Criteria

Absolute Requirements Before Thermal Ablation:

• All patients must undergo puncture biopsy (fine needle aspiration preferred) to confirm benign pathology before thermal ablation 1
• Nodules must be confirmed benign, with cytology excluding malignancy 1, 2

Contraindications to Thermal Ablation:

• Severe bleeding tendency 1
• Severe cardiopulmonary insufficiency or inability to cooperate 1
• Contralateral vocal cord paralysis on the treatment side 1
• Pregnancy and lactation (relative contraindication) 1

Common Pitfalls and Caveats

Availability and Expertise Limitations:

• A 2020 European Thyroid Association survey revealed that thermal ablation was available and personally performed by only a minority of respondents, with surgery remaining the preferred option for most thyroid lesions 4
• Only 13.4% of clinicians refer patients to centers with specific expertise when skills/technology are unavailable 4
• Thermal ablation requires trained operators in specialized centers to achieve optimal outcomes 2

Patient Expectations:

• Volume reduction of 50% should be the expected outcome, not complete nodule elimination 2, 3
• Symptom relief occurs in approximately 78-80% of patients, meaning 20-22% may not achieve satisfactory improvement 3
• Technique efficacy (≥50% volume reduction) is achieved in 86-91% of cases 6

Follow-up Considerations:

• Many patients opt to forgo post-treatment follow-up in real-world practice, which may lead to underestimation of effectiveness 3
• Patients with larger pre-ablation nodule volumes (>30 mL) can still achieve good outcomes, though this exceeds typical study populations 3

Geographic and Practice Variations

The evidence reveals significant geographic inequality in access to minimally invasive techniques, with surgery remaining the default option in many European centers despite available evidence supporting thermal ablation. 4 This highlights the need for:

• Referral to specialized centers when local expertise is unavailable 4
• Development of training programs to expand access to thermal ablation 4
• Patient education about non-surgical options that may not be offered locally 4