2.3.2. [11C]MET

[ 11C]MET, transported mainly by SLC7A5, is often used to visualize parathyroid adenoma and enable focused parathyroidectomy [66–68]. Published data for [11C]MET in TC is limited. Only one case with hyperparathyroidism has been reported, which showed intense focal [11C]MET uptake in a cold nodule with highly increased sestamibi uptake. The nodule was finally diagnosed as FTC, indicating the incremental value of [11C]MET in imaging DTCs [63]. [11C]MET is currently being studied as a surrogate for [18F]FDG in other tumor types, such as brain tumors [69,70] and laryngeal cancer [71]. To date, there is no evidence showing the superiority of [11C]MET over [18F]FDG. Although complementary uptake of 11C-MET and [18F]FDG has been reported in recurrent or metastatic DTCs [72], further clarification and longitudinal study are still required to illustrate the actual value of the [11C]MET in clinic settings. The downside of [11C]MET is the short half-life of 11C (20.4 min), which limits its broad application [73].
