Schenke Simone, Klett Rigobert, Acker Peter, Rink Thomas, Kreissl Michael C, Zimny Michael
Division of Nuclear Medicine, Department of Radiology and Nuclear Medicine, Magdeburg University Hospital.
Institute for Nuclear Medicine Hanau/Gießen/Offenbach/Frankfurt.
Nuklearmedizin. 2019 Jun;58(3):258-264. doi: 10.1055/a-0894-4843. Epub 2019 May 10.
Thyroid scintigraphy with Tc-methoxyisobutylisonitrile (MIBI) is a helpful tool for the risk stratification of thyroid nodules (TN). Whereas a nodule with low or hypointense MIBI uptake has a low risk for malignancy, a hyperintense uptake may indicate a malignant nodule, which requires surgical resection. The appropriate diagnostic or therapeutic regimen of an isointense nodule with an uptake similar to the paranodular tissue is discussed controversially. Aim of this study was to assess the interobserver agreement (IA) for the assignment of TN to the three categories: hypo-, iso-or hyperintense.
Retrospective analysis of planar and SPECT images of MIBI scintigraphy was performed in 36 randomly selected patients with hypofunctioning TN and histological diagnosis. Four observers with different levels of experience in MIBI-scintigraphy analyzed MIBI uptake and assigned the nodules to the appropriate category. To assess the IA, Fleiss' Kappa was calculated.
The study cohort included 11 patients with papillary thyroid carcinoma (diameter 20.3 mm) and 25 patients with benign nodules (diameter 24.8 mm). The IA for all nodules using planar images was 0.76 compared to 0.80 for SPECT images. The IA was better in the subgroup of malignant nodules for planar images as well as SPECT images (Kappa 0.91 and 0.90, respectively) compared to benign nodules (0.65 and 0.76, respectively). Using SPECT images, only one thyroid carcinoma presented with hypointense uptake, the remainder with hyper- or isointense uptake. In contrast, benign nodules were found in all categories.
MIBI scintigraphy shows a good IA for the interpretation of thyroid carcinoma. The IA is further improved if MIBI scintigraphy is performed in SPECT technique.
锝-甲氧基异丁基异腈（MIBI）甲状腺闪烁扫描是甲状腺结节（TN）风险分层的有用工具。MIBI摄取低或呈低强化的结节恶性风险低，而摄取高强化可能提示恶性结节，需要手术切除。对于摄取与结节旁组织相似的等强化结节，其合适的诊断或治疗方案存在争议。本研究的目的是评估观察者间对TN分为低强化、等强化或高强化三类的一致性（IA）。
对36例随机选择的功能减退性TN且有组织学诊断的患者的MIBI闪烁扫描平面及SPECT图像进行回顾性分析。4名在MIBI闪烁扫描方面经验水平不同的观察者分析MIBI摄取情况并将结节归入相应类别。为评估IA，计算Fleiss' Kappa值。
研究队列包括11例甲状腺乳头状癌患者（直径20.3mm）和25例良性结节患者（直径24.8mm）。使用平面图像时所有结节的IA为0.76，而SPECT图像为0.80。与良性结节（分别为0.65和0.76）相比，平面图像及SPECT图像在恶性结节亚组中的IA更好（Kappa值分别为0.91和0.90）。使用SPECT图像时，仅1例甲状腺癌呈低强化摄取，其余为高强化或等强化摄取。相比之下，良性结节在所有类别中均有发现。
MIBI闪烁扫描对甲状腺癌的解读显示出良好的IA。如果采用SPECT技术进行MIBI闪烁扫描，IA会进一步提高。
