Background: To determine whether 18F-fluoro-2-deoxyglucose (18F-FDG)-PET/CT is useful for predicting the BRAF V600E mutation status of a primary papillary thyroid carcinoma (PTC).
Methods: A retrospective analysis was performed in 108 patients who underwent 18F-FDG positron emission tomography-computed tomography (PET/CT) for staging before thyroidectomy and BRAF analysis in biopsy-confirmed PTC. The maximum standardized uptake value (SUVmax) of the primary tumor was calculated according to FDG accumulation. Univariate and multivariate analyses were performed to assess the association between the SUVmax and clinicopathological variables.
Results: The BRAF V600E mutation was detected in 71 of 108 (65.7%) patients. In all subjects, the tumor size and BRAF V600E mutation were independently related to the SUVmax according to multivariate analyses (P = 0.002 and 0.007, respectively). The SUVmax was significantly higher in tumors with the BRAF V600E mutation than in tumors with wild-type BRAF (10.24 ± 11.89 versus 4.02 ± 3.86; P = 0.007). In the tumor size >1 cm subgroup, the BRAF V600E mutation was the only factor significantly associated with the SUVmax (P = 0.016). A SUVmax cutoff level of 4.9 was determined to be significant for predicting the BRAF V600E mutation status (sensitivity 77.4%, specificity 100.0%, area under the curve 0.929; P < 0.0001) according to ROC curve analysis.
Conclusions: The BRAF V600E mutation is independently associated with high 18F-FDG uptake in PTC, especially in those with a tumor size >1 cm.