ROLE OF MAGNETIC RESONANCE IMAGING IN THE ASSESSMENT OF ACTIVE THYROID-ASSOCIATED OPHTHALMOPATHY PATIENTS WITH LONG DISEASE DURATION.

Objective: In thyroid-associated ophthalmopathy (TAO), long disease duration is negatively correlated with the response to immunosuppression treatment. The current treatment decision-making process does not involve magnetic resonance imaging (MRI); thus, we investigated the predictive value of MRI parameters for the immunosuppressive response in active moderate to severe TAO patients with different disease durations. Methods: We retrospectively analyzed the baseline MRI parameters of active TAO patients treated with guideline-recommended weekly glucocorticoid therapy in our center. Data were stratified by the quartile of disease duration. The signal intensity ratio (SIR) of T2-weighted images was used to describe the activity of extraocular muscles (EOMs). Results: Compared to the lowest quartile of disease duration, SIR values of EOMs were significantly lower in quartile 3 (Q3) and quartile 4 (Q4). Meanwhile, the clinical activity score (CAS) curve did not change in parallel and was not correlated with the SIR curve. In the highest quartile of disease duration, nonresponders had significantly lower SIR values of the most inflamed muscle (P = .03) and the medial rectus (P = .004) than did the responders, while no such significance was observed in patients within the lower 3 quartiles. A multivariable predictive model (including CAS, TAO duration, and SIR value) was established in each quartile. The fit of the model was better than CAS with regard to prognostic prediction and showed a high positive predictive value (Model 1: 86.67%; Model 2: 92.86%) and negative predictive value (Model 1: 88.89%; Model 2: 90%) in the top quartile. Conclusion: The anterior manifestation assessed by CAS is not always consistent with retro-orbital activity in long-term TAO patients. CAS is sufficient to reflect disease activity in short-term TAO patients. The supplementation of CAS with orbital MRI would be valuable in selecting appropriate active patients with a long disease duration. Abbreviations: AUC = area under the curve; CAS = clinical activity score; EOM = extraocular muscle; FT3 = free triiodothyronine; FT4 = free thyroxine; GC = glucocorticoid; ivGC = intravenous glucocorticoids; MRI = magnetic resonance imaging; NPV = negative predictive value; PPV = positive predictive value; SIR = signal intensity ratio; TAO = thyroid-associated ophthalmopathy; TRAb = thyroid-stimulating hormone receptor antibody; TSH = thyroid-stimulating hormone.

[Radioiodine treatment of Graves' disease --for its wider indication and application in Japan].

Radioiodine treatment has been well established as an effective and safe therapeutic modality for Graves' disease. To promote more efficient use of this treatment in Japan, a working group has been organized in the Japan Thyroid Association and preparation of guidelines for its clinical use is under way. The treatment using upto 13.5 mCi of I-131 is feasible on out-patient basis. In comparison to the antithyroid drug treatment, the treatment has no side effects, brings in good control of hyperthyroidism and decrease the size of goiter. It is contraindicated in pregnant and lactating women. Patients treated should be carefully monitored for the possible worsening of ophthalmopathy and neonatal Graves' disease. Recent studies revealed the cost-effectiveness of the treatment. Its application to autonomously functioning thyroid nodules and toxic multinodular goiters is also discussed.