Abstract
Purpose: :
To review the clinical activity and severity outcomes of orbital irradiation combined with systemic high dose corticosteroid for Graves' ophthalmopathy (GO) in a North-East Scotland population between 1993-2006.
Methods: :
Sixty-five patients with clinically active GO who received orbital irradiation between 1993-2006 were identified from the database of the Department of Radiotherapy at Aberdeen Royal Infirmary, Scotland UK. The case records of these patients were retrospectively analyzed.All patients were treated with a total dose of 20Gy in 10 fractions to both orbital volumes. The total cumulative equivalent oral corticosteroid dose was calculated for each patient.Thirteen surrogate markers of disease activity and severity were identified, scored on a binary scale and summed to calculate the clinical activity, severity score (CASS) with a total of thirteen. A baseline score was generated immediately prior to radiotherapy and one at last follow-up. These were analyzed with the paired t-test.The effects of potential explanatory variables: age, family history, duration of eye symptoms, smoking status, total corticosteroid dose, duration of eye symptoms to radiotherapy and baseline CASS on the final CASS were analyzed using stepwise linear regression.
Results: :
Mean age was 49.2 years with a median of 48.5. There were 46 females and 36 smokers in the cohort of 65 patients. The mean and median duration of eye symptoms before radiotherapy were respectively 7.4 and 4 months. The median follow-up period was 24 months.The mean CASS at baseline was 6.68 (SD=2.30). The mean CASS at last follow-up was 1.69 (SD=1.13). There was a highly significant decrease in mean CASS between these two time points (p<0.001, paired t-test).Most patient's CASS decreased markedly at last follow-up and CASS reduction was strongly correlated with baseline CASS (r = 0.871, p<0.001). Of the potential explanatory variables considered only CASS baseline had a significant effect on final CASS after radiotherapy. No radiotherapy-associated morbidity was identified within the cohort.
Conclusions: :
There was a highly significant reduction in CASS following combined radiotherapy and high dose corticosteroid treatment and this is in agreement with previously reported data in the literature. The highly significant correlation in reduction between baseline CASS and last follow-up CASS suggests that, to be truly beneficial, disease modifying intervention needs to occur before the onset of proptosis or impaired ocular motility.
Keywords: autoimmune disease • extraocular muscles: structure • radiation therapy