Non-linear Relationship Between Thyroid Weight and I-131 Treatment Efficacy

Overview

This study characterizes the non-linear relationship between thyroid weight and the efficacy of I-131 treatment in Graves' disease, identifying critical thresholds that influence treatment outcomes. An exploratory inflection point at 46 g was noted, with significant predictors including thyroid weight and disease duration.

Background

Graves' disease is a prevalent cause of autoimmune hyperthyroidism, particularly affecting women. I-131 therapy is a standard treatment, yet predicting its efficacy based on thyroid weight remains complex.

Data Highlights

Key Findings

• Thyroid weight shows a significant non-linear association with I-131 treatment efficacy (P-nonlinear = 0.034).
• 40.8% of patients experienced non-remission after initial I-131 therapy.
• Female gender and disease duration >2 years are independent predictors of treatment outcome.
• An exploratory inflection point for thyroid weight was identified at 46 g (P = 0.030).
• RAIU at 3 h was a modest partial mediator of treatment efficacy (mediated proportion: 5.8%).

Clinical Implications

Accurate estimation of thyroid weight is essential for optimizing I-131 dosing strategies.

Conclusion

The findings highlight the complexity of the relationship between thyroid weight and I-131 treatment efficacy.

Related Resources & Content

1. The Journal of Clinical Endocrinology & Metabolism, 2023 -- Impact of Methimazole Discontinuation Duration on I-131 Uptake Assessment via Tc-99m Thyroid Imaging in Patients with Graves’ Disease
2. Frontiers in Endocrinology, 2023 -- Preliminary Volume‑Based Optimization of Radioiodine Dose without radioiodine uptake in Graves' Disease
3. Frontiers in Oncology, 2023 -- Cervical lymph node response to 131I therapy in differentiated thyroid cancer using radiomics and clinical features
4. NICE, 2025 -- Recommendations | Thyroid disease: assessment and management
5. Predictive factors for the efficacy of radioiodine therapy in patients with Graves' disease - PubMed
6. The EANM guideline on radioiodine therapy of benign thyroid disease - PMC
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8. Recommendations | Thyroid disease: assessment and management | Guidance | NICE
9. Predictive factors for the efficacy of radioiodine therapy in patients with Graves' disease - PubMed
10. The EANM guideline on radioiodine therapy of benign thyroid disease - PMC