Protracted Hypofractionated Radiotherapy for Graves' Ophthalmopathy: A Pilot Study of Clinical and Radiologic Response

Abstract

To evaluate the clinical and radiologic response of patients with Graves' ophthalmopathy given low-dose orbital radiotherapy (RT) with a protracted fractionation. Eighteen patients (36 orbits) received orbital RT with a total dose of 10 Gy, fractionated in 1 Gy once a week over 10 weeks. Of these, 9 patients received steroid therapy as well. Patients were evaluated clinically and radiologically at 6 months after treatment. Clinical response assessment was carried out using three criteria: by physical examination, by a modified clinical activity score, and by a verbal questionnaire considering the 10 most common signs and symptoms of the disease. Radiologic response was assessed by magnetic resonance imaging. Improvement in ocular pain, palpebral edema, visual acuity, and ocular motility was observed in all patients. Significant decrease in symptoms such as tearing (p < 0.001) diplopia (p = 0.008), conjunctival hyperemia (p = 0.002), and ocular grittiness (p = 0.031) also occurred. Magnetic resonance imaging showed decrease in ocular muscle thickness and in the intensity of the T2 sequence signal in the majority of patients. Treatments were well tolerated, and to date no complications from treatment have been observed. There was no statistical difference in clinical and radiologic response between patients receiving RT alone and those receiving RT plus steroid therapy. RT delivered in at a low dose and in a protracted scheme should be considered as a useful therapeutic option for patients with Graves' ophthalmopathy.