Introduction: Use of the positron imaging agents, FDG, MET, FLT and FMISO, is expected to lead the way for novel applications aimed at achieving efficient malignancy grading and treatment of gliomas. The aim of this study was to assess four PET studies to estimate the proliferative activities using Ki-67 index and their prognostic values for progression free survival (PFS) and overall survival (OS) in glioma patients.

Methods: PET scans were performed in 25 patients with WHO grade IV glioma, 17 patients with WHO grade III glioma and 8 patients with WHO grade II glioma from April 2009 to December 2013. The resulting PET scans were compared by measuring the T/N ratios of FDG, MET and FLT, as well as T/B ratio of FMISO. The proliferative activities were evaluated using the Ki-67 index. The correlations between the T/N or T/B ratio and the Ki-67 index were determined for all subjects using the non-parametric Spearman’s rank test. The prognostic values between PFS and OS, as well as PET studies were assessed using the Cox proportional hazard model.

Results: The median PFS and OS were 14.6 months and 27.6 months for grade IV glioma. There were differences in the accumulation of each tracer within the same tumor due to the characteristics of each tracer, which may reflect differences in the tissues. We can predict that histological areas with high accumulation of MET, FLT and FMISO to be highly malignant. MET (r=0.36), FLT (r=0.70) and FMISO (r=0.66) were significantly correlated with the Ki-67 index. Both FLT (Hazard ratio=1.1077) and FMISO (Hazard ratio=1.3769) showed the association with PFS. Only FLT was associated with OS (Hazard ratio=1.0732).

Conclusions: PET studies are useful for the preoperative diagnosis of gliomas. The prognostic value as determined by FLT and FMISO PET are associated with PFS in gliomas.

Patient Care: Four PET studies will facilitate more safe and solid management and therapy for the patients with gliomas. It then might predict their prognosis and survival.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Explain knowledge about four PET studies and clinical applications of its measurement. 2) Compare and contrast the usefulness of four PET studies for predicting the diagnosis of gliomas and decision making for surgery and chemotherapy 3) Facilitate that four PET studies predict the prognostic value in gliomas

References: Usefulness of FDG, MET and FLT-PET studies for the management of human gliomas.Miyake K et al, J Biomed Biotechnol. 2012