18F positron emission tomography for glioblastoma

Valentini et al. combined positron emission tomography/computed tomography (PET CT) and conventional and advanced magnetic resonance imaging (MRI) with histology, immunohistochemistry and molecular genetics. Prior to dura opening and tumor resection, forty-eight biopsy specimens [23 of contrast-enhancing (CE) and 25 of non-contrast enhancing (NE) regions] from 12 GB patients were obtained by a frameless image-guided stereotactic biopsy technique. The highest values of 2-[18F]-fluoro-2-deoxy-D-glucose maximum standardized uptake value (18F-FDG SUVmax), relative cerebral blood volume (rCBV), Choline/Creatine (Cho/Cr), Choline/N-acetylaspartate (Cho/NAA) and Lipids/Lactate (LL) ratio have been observed in the CE region. They corresponded to the most malignant tumor phenotype, to the greatest molecular spectrum and stem cell potential. On the contrary, apparent diffusion coefficient (ADC) and fractional anisotropy (FA) in the CE region were very variable. 18F-FDG SUVmax, Cho/Cr and Cho/NAA ratio resulted the most suitable parameters to detect tumor infiltration. In edematous areas, reactive astrocytes and microglia/macrophages were influencing variables. Combined MRI and 18F-FDG PET/CT allowed to recognize the specific biological significance of the different identified areas of GB ¹⁾.

18 F-FDG PET may provide useful information for distinguishing WHO grade 3 glioma/4 gliomas from other malignant brain tumors, but its specificity is limited. Importantly, maximum standardized uptake values (SUVmax) were significantly higher in Primary central nervous system lymphoma than in glioblastoma ²⁾ ³⁾.

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Valentini MC, Mellai M, Annovazzi L, Melcarne A, Denysenko T, Cassoni P, Casalone C, Maurella C, Grifoni S, Fania P, Cistaro A, Schiffer D. Comparison among conventional and advanced MRI, (18)F-FDG PET/CT, phenotype and genotype in glioblastoma. Oncotarget. 2017 Oct 4;8(53):91636-91653. doi: 10.18632/oncotarget.21482. eCollection 2017 Oct 31. PubMed PMID: 29207673; PubMed Central PMCID: PMC5710953.

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Kosaka N, Tsuchida T, Uematsu H et al. 18F-FDG PET of common enhancing malignant brain tumors. AJR Am J Roentgenol. 2008;190 (6):W365–W369.

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Yamashita K, Yoshiura T, Hiwatashi A et al. Differentiating primary CNS lymphoma from glioblastoma multiforme: assessment using arterial spin labeling, diffusion-weighted imaging, and (1)(8)F-fluorodeoxyglucose positron emission tomography. Neuroradiology. 2013;55 (2):135–143.