Context: Graves' orbitopathy (GO), when moderate-to-severe and active, requires medical treatment. High-dose glucocorticoids (GCs) represent the first-line treatment. Orbital radiotherapy (OR) has been used for decades, alone or in combination with GCs, but opinions on its efficacy are conflicting.
Evidence acquisition: The major source of data acquisition included PubMed strategies. Original articles, systemic reviews and metaanalyses, and other relevant citations were screened.
Evidence synthesis: Randomized clinical trials evaluating the efficacy of OR are limited. However, available data suggest that OR is a safe treatment, which seems to be effective particularly on ocular motility impairment, especially if it is of recent onset. OR seems to be effective also on soft tissue changes, whereas exophthalmos and long-standing extraocular muscle dysfunction are poorly affected. OR efficacy on dysthyroid optic neuropathy is uncertain. The combination of OR and oral GCs is more effective than either treatment alone, suggesting a synergistic effect of the two treatments. There is no available evidence that the addition of OR to iv GCs provides an advantage over iv GCs alone.
Conclusions: OR can be considered a safe second-line treatment for patients with moderate-to-severe and active GO but less effective than GCs. A possible strategy may include its use in combination with iv GCs in patients whose GO has only partially responded to a first-course of iv GCs alone and is still active. Future studies might address the question of whether the combination of iv GCs and OR might represent the first-line treatment for active GO.