Diagnostic Accuracy of PET/MR for Evaluating Central Lymph Node Status in Patients with Papillary Thyroid Carcinoma

Abstract

Purpose: Ultrasonography and computed tomography of the neck are commonly used for preoperative evaluation of neck lymph node (LN) status in papillary thyroid carcinoma (PTC). This study evaluated the accuracy of preoperative positron emission tomography/magnetic resonance (PET/MR) imaging of cervical LN status in PTC. F-fluorodeoxyglucose uptake and preoperative morphologic abnormalities of nodal shape, cortical thickness, and the fatty hilum of neck nodes were analyzed using PET/MR imaging. Results: Total thyroidectomy and lobectomy were conducted in 78.2% (223/285) and 21.8% (62/285) of cases, respectively. The status of central neck LN were evaluated in all patients during surgery and additional evaluation of lateral neck LN were conducted in 11.9% (34/285) of patients through selective sampling or modified radical neck dissection. In total, 36.1% (103/285) of patients had pathologic neck LN metastasis (LNM). PET/MR imaging showed an accuracy of 68.8%, sensitivity of 32.7%, and specificity of 88.6% for the detection of central neck LNM; moreover, an accuracy of 95.1%, sensitivity 68.4%, and specificity of 97.0% for lateral neck LNM. PET/MR imaging showed higher accuracy for detecting neck LNM in the 164 patients who did not have suspected clinical thyroiditis than others. Conclusion: PET/MR has a high specificity for detecting central LNM, especially for patients diagnosed with PTC without pathologic thyroiditis.

Head-to-Head Comparison of Neck 18F-FDG PET/MR and PET/CT in the Diagnosis of Differentiated Thyroid Carcinoma Patients after Comprehensive Treatment

“…For head and neck oncologic imaging, it has the potential to achieve the highest level of diagnostic performance. However, to date, the usefulness of PET/MR in head and neck malignancy has not been fully elucidated [ 21 , 22 , 23 ]. It is questionable whether simultaneous PET/MR can provide better diagnostic ability than CT, MRI, and PET/CT in loco-regional recurrent and metastatic cervical lymph nodes [ 16 , 24 , 25 , 26 ].…”