ORIGINAL ARTICLE   

The Quarterly Journal of Nuclear Medicine and Molecular Imaging 2019 September;63(3):311-20

DOI: 10.23736/S1824-4785.17.02961-2

Copyright © 2017 EDIZIONI MINERVA MEDICA

language: English

Diffusion-weighted MRI is not superior to FDG-PET/CT for the detection of neck recurrence in well-differentiated thyroid carcinoma

Pierre VERA ¹ ✉, Agathe EDET-SANSON ¹, Farzaneh QUIEFFIN ², Joseph LE CLOIREC ¹, Anne-Sophie BERTRAND ¹, Martin CAILLEAUX ¹, Jean-Francois MENARD ², Charlotte LUSSEY-LEPOUTRE ^{3, 4}, Francoise CALLONNEC ¹

¹ Department of Nuclear Medicine and Radiology, Henri Becquerel Centre & Quant.I.F - LITIS (Equipe d’Accueil) 4108 - Fédération de Recherche CNRS 3638, Faculty of Medicine, University of Rouen, Rouen, France; ² Department of Statistics, Rouen University Hospital, Rouen, France; ³ Thyroid and Endocrine Tumors Unit, Department of Nuclear Medicine, Pitié-Salpêtrière Hospital, Paris VI University, Cancer Institute, Paris, France; ⁴ INSERM, UMR970, Paris-Cardiovascular Research Center at HEGP, Paris, France

BACKGROUND: Management of patients with well-differentiated thyroid carcinoma (WDTC) and positive thyroglobulin (Tg)/negative iodine-131 whole body scintigraphy (WBS) remains challenging. Here, we investigate the specific role of diffusion-weighted magnetic resonance imaging of the neck (DW-MRI) as compared to rhTSH stimulated FDG-PET/CT in such patients.
METHODS: Patients with WDTC, positive Tg/negative WBS were prospectively enrolled in the study. FDG-PET/CT and neck DW-MRI were performed on the same day after rhTSH stimulation. Neck-US was performed 24 hours after FDG-PET/CT and MRI to guide fine-needle aspiration (FNA). Patients with positive FNA underwent surgery. Patient with negative workup underwent new explorations at 6 and 18 months.
RESULTS: A total of 86 FDG-PET/CT and 83 DW-MRI tests were performed in 40 patients (23 females; 17 males; 52±16 years). For detection of neck recurrences, sensitivity was equivalent for FDG-PET/CT and to DW-MRI at baseline (46% vs. 43%), at 6 months (30% vs. 20%) and at 18 months (11 vs. 10%). The comparison with a non-weighted Kappa test shows significant concordance between FDG-PET/CT and DW-MRI (K=0.741±0.062; P<0.0001). A relationship was observed between Tg and results of FDG-PET/CT, but not for DW-MRI. FDG-PET/CT permitted to detect iodine-refractory distant metastasis in 4 patients.
CONCLUSIONS: In Tg-positive/WBS-negative DTC patients, low tumour burden, neck DW-MRI does not provide additional information compared to rhTSH-stimulated FDG-PET/CT. FDG-PET/CT has the best sensitivity, is acceptable for patients, allows whole body exploration and distant metastasis detections, and is correlated with Tg levels.

KEY WORDS: Diffusion-weighted magnetic resonance imaging; Ultrasonography; Neck; Fluorodeoxyglucose F18; Positron-emission tomography; Thyroid neoplasms