Ablative Versus Conservative Approach for Hyperthyroidism Treatment in Patients with Graves' Orbitopathy: A Retrospective Cohort Study

Abstract

Background: Treatment for Graves' hyperthyroidism (GH) in patients with Graves' orbitopathy (GO) remains a topic of debate. This study aimed to investigate the outcome of GO following glucocorticoids, depending on the chosen thyroid treatment. Methods: This retrospective cohort study included 49 consecutive patients with GH and moderate-to-severe, active GO, as defined by the European Group on Graves' Orbitopathy guidelines. Twenty-four patients were treated with radioactive iodine (RAI) and 25 with methimazole (MMI). All patients were administered intravenous methylprednisolone. Follow-up visits occurred at weeks 24, 48, and 72. The primary endpoint was the overall outcome of GO at week 24. Response was defined as a change in at least two of the following eye features: reduction ≥1 point in clinical activity score; proptosis reduction ≥2 mm; eyelid aperture reduction ≥2 mm; increase in eye ductions ≥8 degrees. Results: Follow-up duration was 72 weeks for both groups (interquartile range 66-72 for RAI and 48-72 for MMI). The proportion of responders for week 24 overall GO outcome was greater in RAI (54.1% vs. 16%; odds ratio [OR] 6.2 [confidence interval (CI): 1.6-23.6], p = 0.0075), but it increased in MMI at weeks 48 and 72, with no differences between groups. There was a trend indicating a better response in RAI regarding individual eye features. Improvement in GO-specific quality of life questionnaire at week 24 was trendily more pronounced in RAI (responders 50% vs. 28% in MMI; OR = 2.5 [CI: 0.7-8.4], p = 0.11), although results were similar in both groups at later time points. At week 24, only one patient (4%) in RAI and three (12%) in MMI experienced worsening of GO. Fifty-nine adverse events were recorded among 36 patients, with no differences between groups, except for infections, which were more frequent in RAI (53.8% vs. 15.3% in MMI; OR = 6.41 [CI: 1.7-23.9], p = 0.0056). Conclusions: RAI appears to be associated with an earlier response of GO to intravenous glucocorticoids. In the long term, a conservative approach also seems to be effective. RAI appears to be relatively safe when patients are concurrently treated with glucocorticoids. However, randomized clinical trials are necessary to confirm these findings.

Keywords: Graves’ disease; Graves’ ophthalmopathy; Graves’ orbitopathy; antithyroid drugs; hyperthyroidism; radioactive iodine; thyroid eye disease; thyroidectomy.