Clinical outcomes of graves' ophthalmopathy treated with intensity modulated radiation therapy.

BACKGROUND: Radiation for Graves' ophthalmopathy (GO) has traditionally utilized lateral opposing fields (LOF) or three-dimensional conformal radiotherapy (3DCRT) technique. The current study was conducted to report clinical outcomes and therapeutic effects of intensity modulated radiation therapy (IMRT) in treating GO patients.

METHODS: One hundred sixteen patients with GO were treated with IMRT as initial local therapy between July 2010 and August 2013, with a median follow-up of 62 months (range 45-81 months). Radiotherapy dose was 20 Gy in 10 fractions within two to three weeks. The immediate and long-term response to IMRT was evaluated in GO severity score and in each category of symptoms. Acute and long-term complications were recorded to assess its safety.

RESULTS: Symptom severity score significantly fell from the start of treatment to 4- or 6- month post-IMRT (P < 0.01). In total, 85 patients (73.3%) experienced improvement of GO symptoms in the first half-year, and only 4 of them (4.7%) suffered recurrence of the GO symptoms during the subsequent follow-ups. Orbital pain, tearing and extraocular muscle dysfunction had the best treatment reaction to IMRT, while proptosis and blurred vision were the most refractory symptoms. Acute complications were slight and self-limited, mainly including intermittent eye redness in 9 patients (7.8%), sideburns hair loss in 19 patients (16.4%), increased milphosis or madarosis in 23 patients (19.8%) and pseudo-progression of GO symptoms in 15 patients (12.9%). For long-term complications, chronic xerophthalmias occurred in 7 patients (6.03%), cataract developed in 2 patients (1.72%), and all were well-managed by medical interventions. Radiation retinopathy and secondary malignancy was not presented in the cohort.

CONCLUSION: The study demonstrated that IMRT could serve as a viable option in treating GO patients, with a satisfactory symptom control ability, and relatively slight and acceptable post-radiotherapeutic complications.