TSPO and neoplasm: At the baseline scan, the percentage of overlap between the CE region and [18F]FET VOI was larger (79–93%) than with [123I]CLINDE SPECT VOI (15–30%) while the percentage of overlap between the two VOI tracers was quite limited, reinforcing that the combination of [18F]FET, TSPO and MR imaging allows detecting the tumor mass beyond CE-MRI at baseline scan.