18F-FDG PET/CT-related metabolic parameters and their value in early prediction of chemotherapy response in a VX2 tumor model

ObjectiveThis study acquired fluorine-18-deoxyglucose (FDG) kinetic parameters prior and subsequent to cisplatin chemotherapy so as to define the optimal parameters for early prediction of chemotherapy response.MethodsA total of 12 non-tumor-bearing rabbits were used to obtain noninvasive input function, five VX2 tumor-bearing rabbits were used for validation and 32 tumor-bearing rabbits underwent 4 mg kg−1 cisplatin chemotherapy. Dynamic FDG PET/CT was performed at pretherapy, Day 0, Day 1, Day 7 and Day 14 after cisplatin administration. With the application of a three-compartment model, influx index (Ki), k1, k2, k3 and k4 were noninvasively obtained.ResultsSensitive (SG) and insensitive groups (ISG) were defined based on their volume on Day 7. k1, Ki, SUVmean, and SUVmax showed significant decreases in SG vs. ISG at Day 0 (P<.076–0.0001). k1 demonstrated sustained (up to Day 7) differences (P<.028–0.0072), and k2, k3 and k4 showed no significant differences at any time point (P>.05). Soon after cisplatin administration, GLUT-1 expression was greatly decreased in SG vs. ISG.ConclusionsThe parameters of SUVmax, SUVmean, Ki and k1 were valuable for the early prediction of chemotherapy response. k1 had a wider observation window compared to SUVmean, SUVmax and Ki, and k1 also reflected the changes in GLUT-1 expression.