抗甲状腺球蛋白抗体和18F-FDG符合线路显像在分化型甲状腺癌随访中的临床应用

目的 探讨分化型甲状腺癌(DTC)手术和131Ⅰ治疗后,血清甲状腺球蛋白(Tg)水平阴性时,血清抗甲状腺球蛋白抗体(TgAb)是否可以反映DTC的复发和转移以及18F-FDG SPECT符合线路显像对这些患者的诊断灵敏度和临床随访价值.方法 对52例临床经手术和131Ⅰ清除残余甲状腺治疗后的DTC患者随访发现11例患者(21.15%)的血清TgAb浓度均为阳性(＞40 IU/ml,范围为84.0～5450.0 IU/ml),但血清Tg＜0.2 ng/ml;随访期间行18F-FDG SPECT符合线路显像和131 Ⅰ全身显像,计算其诊断复发转移灶的灵敏度、特异性,必要时行全身骨显像、X/CT、B超、MRI检查等.结果 11例血清TgAb浓度均为阳性的患者中18F-FDG SPECT符合线路显像和131Ⅰ全身显像共发现8例患者阳性病灶13个,18F-FDG SPECT符合线路显像发现阳性病灶8个,其中纵膈转移2个,颈部病灶(包括残留病灶和颈淋巴结转移)6个,阴性病灶5个(假阴性),其中颈淋巴结转移3个,纵膈和肺转移各1个,18F-FDG SPECT符合线路显像的灵敏度61.5%,特异性100%,阳性预期值100%;131Ⅰ全身显像发现阳性病灶10个,其中纵隔转移2个,肺转移1个,颈部病灶(包括残留病灶和颈淋巴结转移)7个,阴性病灶3个(假阴性),其中纵隔转移1个,颈淋巴结转移2个,131Ⅰ全身显像灵敏度76.92%,特异性lOO%,阳性预期值90.9%.结论 当DTC患者上血清Tg处于低水平状态时,如果TgAb水平持续升高,可以作为诊断DTC转移或复发的一个有价值的肿瘤标志物.18F-FDG SPECT符合线路显像对DTC复发和转移较敏感,可用于血清TgAb浓度升高而Tg水平阴性时的DTC复发和转移的监测.

Clinical application of antithyroglobulin antibodies and 18F-FDG coincidence circuit imaging in the follow up of differentiated thyroid carcinoma

Objective To investigate whether antithyroglobulin antibody (TgAb) could reflect the relapse and metastasis of differentiated thyroid carcinoma (DTC) when serum thyroglobulin was negative after operation and ¹³¹I treatment, and to study the diagnostic sensitivity and follow-up value of ¹⁸F-FDG dual head coincidence imaging to these patients. Methods TgAb positive (>40 IU/ml, range from 84.0 IU/ml to 5450.0 IU/ml) was found in 21.5% (11/52) patients after thyroid ablation and ¹³¹I treatment, while the serum Tg was less than 0.2 ng/ml. The ¹⁸F-FDG dual head coincidence imaging and ¹³¹I scintigraphy were both performed during the follow-up, so as the whole body skeletal scintigraphy, X/CT imaging, ultrasound examination and MRI imaging when necessary. Results Thirteen foci of infection in total were observed on ¹⁸F-FDG dual coincidence circuit imaging and ¹³¹I whole body scintigraphy in the 72.3% (8/11) patients with positive TgAb results. Eight foci were positive on ¹⁸F-FDG dual coincidence circuit imaging, including 2 in the mediastinum, 6 in the neck and 5 focus were negative, including 3 cervical lymph node metastasis area, 1 in the lung and 1 in the mediastinum. The diagnostic sensitivity, specificity and positive predictive value of ¹⁸F-FDG dual coincidence circuit imaging was 61.5% (8/13), 100% and 100 %, respectively. Ten foci were found positive on the ¹³¹I whole body scintigraphy, including 2 in the mediastinum, 1 in the lung and 7 in the cervical parts. Three focus were found negative, including 1 in the mediastinum and 2 in the lymphonodi cervicales. The sensitivity, specificity and positive predictive value of ¹³¹I whole body scintigraphy was 76.92% (10/13), 100% and 90.9%, respectively. Conclusion The continuing high level of TgAb can serve as one valuable tumor marker to predict the recurrence and metastasis of DTC when the serum Tg is normal. The ¹⁸F-FDG dual coincidence circuit imaging, which is very sensitive to the relapse and Mets, can play supplementary role to the ¹³¹I whole body scintigraphy when the serum level of Tg is negative and TgAb is high.