2026 NASIT Statement: The Application of Embolization in the Management of Thyroid Diseases

Full name: North American Society for Interventional Thyroidology (NASIT) Expert Statement on Thyroid Artery Embolization (TAE), published in Endocrine Practice, August 2026 Core positioning: Multidisciplinary expert statement on thyroid artery embolization (TAE). It clarifies TAE as a selective minimally invasive endovascular alternative, not first-line routine therapy; compares TAE with surgery, radioiodine and thermal ablation, defines patient selection, procedural standards, safety monitoring and palliative application for partial thyroid malignancies.

1. Background & Core Principle

Thyroid artery embolization (TAE) occludes feeding arteries of thyroid gland via endovascular microcatheter, inducing focal ischaemic necrosis, reducing gland volume, vascularity and hormone secretion. NASIT emphasizes: TAE belongs to interventional radiology technique and must be delivered within multidisciplinary thyroid MDT (endocrinology, thyroid surgery, interventional radiology). TAE is not a replacement for surgery or radioiodine, reserved for selected patients who are high surgical risk, contraindicated to radioiodine, or for preoperative devascularization.

2. Indications (Stratified Recommendations)

✅ Benign thyroid disorders (primary applicable population)

1. Large symptomatic benign thyroid nodule, volume＞30 mL, compressive symptoms (neck pressure, dyspnoea, dysphagia);
2. Multinodular goiter＞50 mL, substernal/mediastinal extension;
3. Toxic multinodular goiter or Graves’ disease: poor response to antithyroid drugs, contraindicated to radioiodine, high surgical risk;
4. Autonomously functioning thyroid nodule＞15 mL.

✅ Preoperative adjuvant embolization

For highly vascular massive goiter or difficult thyroid surgery (transoral/transaxillary minimally invasive thyroidectomy). TAE reduces intraoperative blood loss, surgical duration and risk of neck haematoma. Surgery should be performed within 36–72 hours after TAE.

✅ Emergency haemostasis

Spontaneous or post-biopsy / postoperative acute neck bleeding from thyroid.

✅ Palliative use in thyroid malignancy

Local advanced, unresectable thyroid carcinoma, for pain relief, haemorrhage control and tumour vascular reduction; not curative radical therapy.

3. Contraindications

1. Absolute: Contrast medium severe allergy, severe uncorrectable coagulopathy, active thyroid storm (only TAE can be considered as salvage rescue after medical stabilization).
2. Relative: Poor distal vascular anatomy with high risk of non-target embolization, pregnancy.

4. Pre-procedure MDT Assessment

1. Thyroid function, TSH, FT3, FT4, TRAb for Graves disease;
2. Thyroid US + contrast-enhanced CT: nodule volume, gland vascularity, substernal extension, mapping of superior/inferior thyroid arteries and collateral circulation;
3. Vocal cord evaluation, calcium/PTH baseline for parathyroid protection;
4. Preoperative counselling: TAE is volume-reducing/palliative, not guaranteed to achieve permanent euthyroidism.

5. Technical Specifications & Embolic Agents

1. Angiographic mapping of bilateral superior and inferior thyroid arteries; identify dangerous collaterals to laryngeal arteries, spinal vessels.
2. Embolic material selection:
   • Benign goiter/nodule: Polyvinyl alcohol (PVA) particles, preferred for volume reduction;
   • Acute bleeding: microcoils or liquid NBCA glue for rapid haemostasis.

Key warning: Prevent non-target embolization to recurrent laryngeal artery, parathyroid vessels, vertebral circulation.

6. Clinical Outcomes

• Benign large nodules / goiter: 32–73% volume reduction at 6 months; compressive symptoms improved in most patients.
• Toxic goiter/Graves: Euthyroid rate＞70%, sustained effect up to 50 months, but recurrence is possible.
• Preoperative TAE: Intraoperative blood loss significantly decreased.

7. Safety & Complications

Minor, self-limited (common):

Post-embolization syndrome: neck pain, fever, odynophagia, transient fatigue, usually resolves within 1–7 days.

Severe but rare:

Non-target embolization → recurrent laryngeal nerve palsy, parathyroid ischaemia/hypoparathyroidism, stroke, skin necrosis.

NASIT recommendation: operators must receive specialized training in head and neck interventional radiology.

8. Post-procedure Follow-up

1. 1 week: Thyroid function, calcium/PTH, neck symptom assessment.
2. 1,3,6,12 months: Thyroid ultrasound, volume measurement, thyroid function.
3. Long-term: Monitor hypothyroidism or recurrent hyperthyroidism.

• If residual hyperthyroidism or nodule regrowth: repeat TAE, radioiodine or surgery can be re-evaluated.

9. Comparison with other thyroid therapies

1. Surgery: Definitive resection, higher anaesthesia and bleeding risk for large substernal goiter; TAE as preoperative adjunct.
2. Radioiodine: First-line for many hyperthyroidism patients; contraindicated in pregnancy, breastfeeding, large compressive goiter.
3. Thermal ablation (RFA/MWA): Best for small-to-medium benign nodules; TAE is more suitable for huge hypervascular goiter / substernal extension.

10. Evidence Gaps & Limitations

1. No large randomized controlled trials comparing TAE vs surgery or radioiodine; evidence mainly from cohort studies and single-centre series.
2. Long-term (＞5 years) recurrence and hypothyroidism data remain limited.
3. TAE is only available in specialized high-volume MDT centres, not widely accessible in primary care.
4. Lack of standardized technique protocol across centres.

11. Cross alignment with previous guideline series

1. This NASIT 2026 statement: minimally invasive endovascular TAE for large/compressive or high-risk thyroid disease, MDT patient selection;
2. Previous metabolic/endocrine consensus series focus on diabetes, obesity, cardiorenal protection, menopause and androgen deficiency; this document shifts to thyroid interventional minimally invasive therapy.
3. Complementary to NASIT thermal ablation statement for low-risk papillary thyroid carcinoma; TAE targets larger, hypervascular and compressive disease, while thermal ablation applies to smaller low-risk nodules.

Disclaimer: This summary is for academic study only, not clinical operational guidance. TAE is an interventional radiology procedure, requiring MDT evaluation and performed by trained operators.