Based on the literature and our current findings, we suggest to use SSTR PET as first-line molecular imaging test for biopsy-proven TC, whereas for AC the choice between SSTR PET and [18F]FDG PET could be made based on tumour biology (e.g. if high Ki-67 index or mitotic count, start with [18F]FDG). This evidence concerns the gene MKI67 and neoplasm.