The Efficacy of Radiation Therapy in the Treatment of Graves’ Orbitopathy
Introduction: The goals of this study were to:
- evaluate institutional outcomes for Graves’ orbitopathy (GO) patients treated with radiation therapy (RT) (with and without surgical intervention)
- evaluate the role of orbital reirradiation (secondary goal)
- find prognostic factors for achieving a complete response (CR) to RT (secondary goal)
Methods: A retrospective review of 211 consecutive patients was undetaken; they had all been referred to the authors’ department for GO treatment between January 2001 and January 2010. Two patients were lost to follow-up and did not receive RT, so there were 209 patients in the final evaluation of RT efficacy.
The median age was 51 years (range: 15-84 years), and there were 63 male patients and 146 female patients. At initial ophthalmologic evaluation, thyroid disease history was taken, and the disease breakdown was: 87.6% hyperthyroidism, 3.3% hypothyroidism, and 9.1% no thyroid disease history.
The most common symptoms at presentation were: proptosis (90.9%), extraocular muscle impairment (78.9%), soft tissue signs (68.4%), and diplopia (58.4%).
Before RT, 20.6% of patients (43) had corticosteroid therapy; 41 of them were referred for RT after that (the other 2 were referred to surgery).
In 8.6% of patients (18), surgery was used before RT
The RT dose was 20 Gy in 10 fractions. Median follow-up was 11 months (range: 1-88 months). For patients who achieved either CR or partial response (PR), the prognostic factors were evaluated.
Results: In 96.7% of the patients (202), disease stabilization without recurrence was achieved following RT. There was a patient-reported improvement of pre-treatment symptoms in 84.2% of patients (176) after RT was done.
Complete response of GO symptoms was achieved using multiple modalities. There were 93 patients with a CR after all therapy.
Corticosteroids were stopped in 97.8% of patients who had received that as initial therapy.
After RT, 68.9% (144) required surgery.
Orbital reirradiation was needed in 14 patients who had persistent or recurrent symptoms. Of those patients, 5 achieved CR and 9 achieved disease stabilization but continued to have persistent ocular symptoms.
Gender alone predicted CR in the prognostic factors evaluated; CR was less common in men than in women (33.9% vs 49.7%, p = 0.0471).
Conclusion: In patients who do not respond to initial RT or who have symptom recurrence, orbital reirradiation is beneficial; there is not an apparent risk of increased morbidity.
This is one of the largest studies of orbital irradiation for GO. Although retrospective, it provides useful outcomes data on a large number of patients with symptomatic GO treated over 9 years at a single institution. The majority of patients reported symptomatic improvement after radiation therapy (RT), although roughly 70% required further surgical management. The final outcome was complete or partial response of GO to this multimodality therapy.
The other messages are orbital surgery was feasible after RT and even orbital re-irradiation was beneficial in those patients who needed it.