促甲状腺激素水平对^(18)F-FDG PET/CT诊断分化型甲状腺癌失分化后复发及转移灶的影响

The influence of TSH expression on the diagnotic efficiency of ^(18)F-FDG PET/CT in the detection of recurrence/metastasis of dedifferentiated thyroid carcinoma

目的探讨促甲状腺激素(thyroid stimulating hormone,TSH)水平对18F-氟代脱氧葡萄糖(18F-fluorodeoxyglucose,18F-FDG)正电子发射计算机断层显影术(positron emission tomography/computed tomography,PET/CT)诊断甲状腺球蛋白(thyroglobulin,TG)阳性而131I-诊断剂量全身显像(131I-diagnostic whole-body scanning,131I-dWBS)阴性的分化型甲状腺癌(differentiated thyroid carcinoma,DTC)失分化后复发和转移灶的影响。方法征得患者同意后,将60例欲行18F-FDG PET/CT检测的分化型甲状腺癌术后患者(TG阳性而131I-dWBS阴性)随机分为低TSH组(30例)和高TSH组(30例)。以术后组织病理学或至少6个月的临床和影像学随访结果为诊断病灶性质的标准,得出其阳性预测值(positive predictive value,PPV),比较TSH水平高低对18F-FDG PET/CT检测结果的影响;分析TG水平与放射性浓聚病灶的标准摄取值(standardized uptake value,SUV)间的关系。结果高TSH水平及低TSH水平下18F-FDG PET/CT诊断DTC复发和转移灶的阳性预测值分别为96.7%和80.0%(P<0.05);患者TG水平与SUV呈正相关。结论 18F-FDG PET/CT对于TG阳性而131I-dWBS阴性DTC患者复发和转移灶的诊断,在高TSH水平下较低TSH水平有更高的敏感性与特异性,此可能与TSH刺激肿瘤组织对18F-FDG的摄取相关。

Objective To explore the influence of thyroid stimulating hormone （TSH） expression on the diagnostic efficiency of 18 F-FDG PET/CT in the detection of recurrence or metastasis of differentiated thyroid carcinoma（DTC） in patients with elevated expression of thyroglobulin（TG） and negative 131I-diagnostie whole body scan （131I-dWBS）. Methods 30 DTC patients with high TSH expression and another 30 patients with low TSH （without or with administration of thyradin） with high TG expression but negative 131I-dWBS were detected by PET/CT. The diagnosis standard was based on histopathologic findings or clinical/imaging follow-up results within 6 months. The positive predictive values（PPVs） were obtained and the influence of TSH expression on the diagnostic efficiency of PET/CT was compared ,furthermore, the relationship between TG and standardized uptake values（SUVs） of 18 F-FDG was analyzed as well. Results Eneouragingly, for detecting the reeurrence/metastasis of dedifferentiated thyroid carcinoma,the PPV of PET/CT in the high and low TSH groups were 96.7% and 80.0%, respectively, showed a significant difference（ P 〈 0.05 ）. Moreover, the TG was positively correlated with SUVs. Conclusions The diagnostic efficiency of PET/CT in high TSH group is stronger than that in low TSH group for detecting the recurrences/metastases of DTC in patients with high TG levels bat negetive 131I-dWBS, which is probably due to the elevated uptake of is F-FDG stimulated bv TSH.