[The application of 99Tcm-DTPA orbital SPECT/CT in staging evaluation of thyroid associated ophthalmopathy].

Objective: To explore the application value of 99Tcm-diethylenetriaminepentaacetic acid (DTPA) orbital single photon emission computed tomography/computed tomography (SPECT/CT) in staging evaluation of thyroid associated ophthalmopathy (TAO). Methods: A case-control study. A total of 40 patients with binocular TAO were recruited from May 2019 to December 2019 in the Second Hospital of Dalian Medical University. According to the clinical activity score (CAS) standard, 40 TAO patients were divided into the active group (15 cases) and the inactive group (25 cases), and 10 healthy volunteers were recruited as the control group. All subjects underwent 99Tcm-DTPA orbital SPECT/CT examination, and each subject's CAS, reading results and maximum standardized uptake value (SUVmax) were recorded. The Kruskal-Walis H test was used for the CAS comparison among the three groups. The analysis of variance was used for the SUVmax comparison among the three groups. The comparison between CAS and SUVmax before and after treatment was performed by paired samples Wilcoxon signed rank test and paired-sample t test, and Spearman correlation analysis was performed between SUVmax and CAS. The Kappa test was used to check the consistency between the reading result and CAS's judgment of TAO activity. The receiver operating characteristic curve was used to analyze the diagnostic value of the reading results and SUVmax for TAO. Results: The age difference among the three groups was not statistically significant, and the gender difference was not statistically significant (all P>0.05). The difference in CAS among the three groups was statistically significant (H=39.894; P<0.01). Patients with active TAO showed abnormal concentration and enhancement of nuclides in the orbital tissue, and the uptake of radionuclides was significantly increased, while patients with inactive TAO had a slight increase, and healthy volunteers had no significant or only mild uptake. The SUVmax of the active group (2.24±0.47) was highest, and that of the inactive group (1.57±0.43) was higher than the healthy control group (0.67±0.22). After pairwise comparison, there were statistical differences between groups (all P<0.05). According to Spearman correlation analysis, the SUVmax of all TAO patients was linearly, positively correlated with their CAS (r=0.753; P<0.05). In assessing the clinical activity of TAO, the reading results were consistent with CAS (Kappa value=0.737; P<0.05). Taking the reading results as the standard, the area under the receiver operating characteristic curve (AUC) of SUVmax was 0.992, and the threshold of SUVmax to distinguish between active and inactive periods was 1.850, with a sensitivity of 86.70% and a specificity of 76.00%. Taking CAS results as the standard, the AUC of SUVmax was 0.853, and the threshold of SUVmax to distinguish between active and inactive periods was 1.850, with a sensitivity of 100.00% and a specificity of 87.50%. Five patients had inconsistent SUVmax and CAS. The CAS was ≥3, but the orbits did not show any inflammatory lesions in two of them; the CAS was<3, but the orbits showed inflammatory lesions in three of them. Thirteen active TAO patients with 99Tcm-DTPA orbital SPECT/CT showing significant accumulation of nuclides were given hormone shock therapy 12 times. After treatment, the CAS 2.00 (2.00) was lower than the pre-treatment 3.00 (1.50) score, and the difference was statistically significant (Z=-3.100, P<0.01). The SUVmax after treatment (1.60±0.20) was lower than the pre-treatment value (2.17±0.34), and the difference was statistically significant (t=10.197, P<0.01). Conclusion:99Tcm-DTPA orbital SPECT/CT can relatively accurately determine the state of orbital inflammation in patients with TAO, and can be used as a useful supplement to evaluate the clinical activity of TAO, helping to guide clinical treatment. (Chin J Ophthalmol, 2021, 57: 830-836).目的： 探讨99Tcm-二乙烯三胺五乙酸（DTPA）眼眶单光子发射计算机断层扫描/计算机断层扫描（SPECT/CT）在甲状腺相关眼病（TAO）分期评价中的应用价值。 方法： 病例对照研究。选取2019年5至12月在大连医科大学附属第二医院就诊并行99Tcm-DTPA眼眶SPECT/CT检查的40例双眼发病的TAO患者资料，根据临床活动性评分（CAS）标准，分为TAO活动期组（15例）和TAO非活动期组（25例）；同时纳入10名健康志愿者为对照组。比较3组间99Tcm-DTPA眼眶SPECT/CT图像的最大标准化摄取值（SUVmax），分析SUVmax与CAS的相关性及阅片结果与CAS在评估TAO临床活动性的一致性，采用受试者工作特征曲线（ROC）分析SUVmax对TAO活动性的诊断价值。比较患者治疗前、后的CAS及SUVmax。统计学主要采用Kruskal-Walis H检验、方差分析、配对样本Wilcoxon符号秩和检验、配对样本t检验、Spearman相关性分析、Kappa检验等。 结果： 3组间年龄、性别差异均无统计学意义（均P>0.05）；CAS差异有统计学意义（H=39.894；P<0.01）。活动期TAO患者SPECT/CT图像可见放射性核素在眼眶组织中异常浓聚、增强，核素摄取明显增高；非活动期TAO患者核素摄取轻度增高；健康志愿者组无明显或仅有轻度的核素摄取。TAO活动期组、TAO非活动期组、对照组SUVmax分别为2.24±0.47、1.57±0.43、0.67±0.22，两两比较差异均有统计学意义（均P<0.05）。Spearman相关性分析显示TAO患者的SUVmax与CAS呈线性正相关（r=0.753，P<0.05）。阅片结果与CAS评估患者TAO临床活动性具有一致性（Kappa系数为0.737，P<0.05）。以阅片结果为标准，SUVmax判断TAO活动性的ROC曲线下面积（AUC）为0.992，阈值为1.850，灵敏度为86.70%，特异度为76.00%；以CAS结果为标准，SUVmax的AUC为0.853，阈值为1.850，灵敏度为100.00%，特异度为87.50%。5例患者阅片结果与CAS判断TAO活动性存在不一致，其中2例患者CAS≥3分，但眼眶图像未显示任何炎性反应病变；3例患者的CAS<3分，但眼眶图像显示炎性反应病变。13例SPECT/CT显示为活动期的患者进行了12次糖皮质激素冲击治疗，治疗后的CAS［中位数（四分位间距）］为2.00（2.00）分，低于治疗前的3.00（1.50）分；治疗后的SUVmax为1.60±0.20，低于治疗前的2.17±0.34，差异均有统计学意义（Z=-3.100，t=10.197；均P<0.01）。 结论：99Tcm-DTPA眼眶SPECT/CT能相对准确地判断TAO患者眼眶炎性反应的状态，可作为评价TAO临床活动性的有益补充，从而更准确地指导临床治疗。（中华眼科杂志，2021，57：830-836）.