The value of ^99mTc-DTPA orbital SPECT in the drug treatment of thyroid associated ophthalmopathy

Objectives To investigate the efficacy of ^99mTc-DTPA orbital SPECT (TOS)in directing the treatment of thyroid associated ophthalmopathy(TAO) with periocular injection of Octreotide(OT) or Triamcinolone Acetonidc(TA).

Methods Of 50 patients with active TAO,clinical activity scores(CAS)≥3 and positive TOS,were divided into two groups treated with OT Group (OG,20 cases) or TA Group (TG,50 cases),respectively.And 12 normal volunteers were enrolled as the control(CG).CAS score,TOS and uptake ratio(UR) were detected before and after the treatment.Exophthahnometry measurements,intraocular pressure and TAO related ocular signs,including von-Graeve's sign(Gs),Dalrymple's sign(Ds) and Eniroth's sign(Es) were recorded during the treatment.The incidence of adverse reactions was also evaluated.

Results Before treatment,the patients UR levels were significantly higher than CG (F=22.517, <0.001) and no difference was found between OG and TG (P>0.05). After treatment,the UR 1evels in patients were decreased significantly (tOG=5.3l, <0.01; tTG=4.34, <0.01), and approximate to the normal (>0.05). Accordingly,the patients CAS were obviously declined after treatment (tOG=4.21, <0.01; tTG=3.89, <0.01). In addition,exophthalmia was obviously alleviated after treatment (OG:3.48mm; TG:2.61mm). As to the TAO related ocular signs,only the occurrence of Es showed a substantial decline in OG (χ2=11.958, <0.01). While,all signs frequency,including Gs,Ds and Es were significantly declined in TG (χ2=32.19,41.36 and 26.27, <0.01). The intraocular pressure showed no obvious change in both treated groups. But higher frequency of adverse reactions were found in TG compared with OG (χ2=5.396, <0.05).

Conclusions The TOS plays a critical role in evaluating the clinical activity of TAO.The patients with positive TOS show better therapeutic efficacy of OT or TA.Both drugs decrease the exophthalmia degree without elevating the intraocular pressure.Compared with OT,TA could more efficiently invert the ocular signs,but with higher frequency of adverse reactions