Cancer Management and Research (Mar 2021)
Value of 18F-FDG Hybrid PET/MR in Differentiated Thyroid Cancer Patients with Negative 131I Whole-Body Scan and Elevated Thyroglobulin Levels
Abstract
Hongyan Li,1,2 Xiaomin Chen,1,2 Yajing Zhang,1,2 Kun Wang,1,2 Zairong Gao1,2 1Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China; 2Hubei Province Key Laboratory of Molecular Imaging, Wuhan, 430022, People’s Republic of ChinaCorrespondence: Zairong GaoDepartment of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1277 Jiefang Avenue, Wuhan, 430022, People’s Republic of ChinaTel/Fax +86-27-85726426Email [email protected]: To evaluate the diagnostic performance of 18F-FDG PET/MR in detecting recurrent or metastatic disease in patients with differentiated thyroid cancer (DTC) who have increased thyroglobulin (Tg) levels but a negative 131I whole-body scan (WBS). The relationship between 18F-FDG PET/MR and serum Tg levels was explored. We also evaluated the therapeutic impact of PET/MR on patient clinical management.Patients and Methods: Twenty-nine DTC patients with a negative 131I-WBS of the last post-therapeutic and increased Tg levels under thyroid-stimulating hormone suppression treatment who underwent 18F-FDG PET/MR examination were retrospectively analyzed.Results: Of those 29 patients, 18F-FDG PET/MR findings were true positive, true negative, false positive, and false negative in 18, 7, 2, and 2 patients, respectively. The overall sensitivity, specificity, and accuracy were 90.0%, 77.8%, and 86.2%, respectively. We noticed significant differences in serum Tg levels between the PET/MR-positive and PET/MR-negative patient groups (P=0.049). Receiver operating characteristic curve analysis showed that a Tg level of 2.4 ng/mL was the optimal cut-off value for predicting PET/MR results. The sensitivity, specificity, and accuracy of PET/MR were higher in patients with Tg levels greater than 2.4 ng/mL than in patients with lower levels. By detecting recurrent or metastatic disease, 18F-FDG PET/MR altered the clinical management in 7 patients (24.1%) of the overall population.Conclusion: 18F-FDG PET/MR has high diagnostic accuracy for detecting recurrent or metastatic diseases in DTC patients and is useful for clinical management.Keywords: 18F-FDG, PET/MR, differentiated thyroid cancer, thyroglobulin
