18F-FDG-PET/CT cannot simply distinguish malignant and benign tumors in retroperitoneal/intra-abdominal cavity; however, the SUVmax of malignant tumors, inflammatory pseudotumor, and PPGL group is higher than the SUVmax of benign tumors, lymph node metastasis, hematoma, and low malignant STS group.
In particular, <sup>68</sup>Ga-DOTA-TOC PET/CT was able to detect the TIO with a negative or a false-positive result of a previous <sup>111</sup>In-pentetreotide SPECT/CT in 5/8 patients (63%) or a previous FDG PET/CT in 7/11 patients (64%).