Technetium‐99m‐anti‐tumour necrosis factor alpha scintigraphy as promising predictor of response to corticotherapy in chronic active Graves' ophthalmopathy

Abstract

It has been suggested that technetium-99m (99mTc)-anti-tumour necrosis factor alpha (TNF-α) scintigraphy (SCI) may be a useful diagnostic tool in Graves' ophthalmopathy (GO). This study evaluated whether orbit total radioactivity uptake on SCI could be used to predict corticosteroid therapy (CorT) responses in active-GO patients. A longitudinal study of patients with active GO defined by Clinical Active Score (CAS) >3/7 was done. Clinical, laboratory and SCI evaluations were performed at baseline and 3months after concluding intravenous CorT. SCI (planar and tomographic) was assessed after intravenous injection of 10mCi of 99mTc-anti-TNF-α. Orbits and cerebral hemispheres were defined as regions of interest (ROIs) to enable orbit/hemisphere ROI-ratios of total radioactive uptake. ROI-ratios were considered positive at >2·5. Average total radiation uptake (TRU) was also determined for each orbit (AVGROI ). Clinical, laboratory and SCI data were compared between responders (CAS became inactive) and non-responders to CorT (18 patients). At baseline, AVGROI were higher in active OG orbits (67·3cps) than in inactive ones (33·6cps; P<0·05). AVGROI (absolute values) reduced (-29·9cps) in CorT responders and tended (P=0·067) to differ from variations occurred in non-responders (+6·9 cps in patients with maintained CAS positivity post-treatment). Higher baseline ROI-ratios (4·9 versus 3·3; P=0·056) and its pronounced reductions following CorT (-37% versus +56% in non-responders; P=0·036) tended to be associated with good CorT responses in the subgroup of GO history ≥1year. SCI showed a good association with active eye disease and may be an additional tool to identify CorT responders.