Uptake pattern of dual-nuclide PET in intracranial lesions

Background To analyze the uptake patterns of dual-nuclide PET using 2-[ 18 F]-fluoro-2-deoxy- D -glucose (FDG) and O-(2-[ 18 F]-fluoroethyl)- L -tyrosine (FET) in intracranial lesions. Methods This study was conducted from July 2023 to September 2024. Patients with intracranial lesions underwent FDG PET and FET-PET scans on separate days before surgery. Four uptake patterns were observed: type A, positive uptake of both FET and FDG; type B, positive uptake of FET with negative uptake of FDG; type C, negative uptake of FET with positive uptake of FDG; and type D, negative uptake of both FET and FDG. Correlations between standardized uptake values (SUVs) of FET/FDG and tumor proliferation marker Ki-67/tumor protein p53 (P53) were analyzed using Pearson correlation analysis. Results Among 28 patients, type A was observed in 17, type B in nine, and type D in two patients. Dual-nuclide PET-based diagnoses were completely consistent with the pathology in nine, partially consistent in 17, and inconsistent in only two patients. Except for mature teratomas, all intracranial tumors demonstrated positive FET uptake. Correlations were observed between FDG and Ki-67: SUV max ( P = 0.011) and SUV mean ( P = 0.012). In addition, correlations were observed between the FDG/FET ratio and Ki-67: SUV max ( P = 0.029) and SUV mean ( P = 0.021). Conclusion Dual-nuclide PET is valuable in diagnosing intracranial lesions. Type A is the most common uptake pattern. The SUV of FDG is positively correlated with the Ki-67 level. Compared with single-modality PET, dual-nuclide PET uptake patterns provide diagnostic insights into intracranial lesions.