Aim To study the association of metabolic features of 18F-fluorocholine in gliomas with histopathological and molecular parameters, progression-free survival (PFS) and overall survival (OS). Methods Prospective multicenter and nonrandomized study (Functional and Metabolic Glioma Analysis). Patients underwent a basal 18F-fluorocholine PET/CT and were included after histological confirmation of glioma. Histological and molecular profile was assessed: grade, Ki-67, isocitrate dehydrogenase status and 1p/19q codeletion. Patients underwent standard treatment after surgery or biopsy, depending on their clinical situation. Overall survival and PFS were obtained after follow-up. After tumor segmentation of PET images, SUV and volume-based variables, sphericity, surface, coefficient of variation, and multilesionality were obtained. Relations of metabolic variables with histological, molecular profile and prognosis were evaluated using Pearson χ2 and t test. Receiver operator caracteristic curves were used to obtain the cutoff of PET variables. Survival analysis was performed using Kaplan-Meier and Cox regression analysis. Results Forty-five patients were assessed; 38 were diagnosed as having high-grade gliomas. Significant differences of SUV-based variables with isocitrate dehydrogenase status, tumor grade, and Ki-67 were found. Tumor grade, Ki-67, SUVmax, and SUVmean were related to progression. Kaplan-Meier analysis revealed significant associations of SUVmax, SUVmean, and multilesionaly with OS and PFS. SUVmean, sphericity, and multilesionality were independent predictors of OS and PFS in Cox regression analysis. Conclusions Metabolic information obtained from 18F-fluorocholine PET of patients with glioma may be useful in the prediction of tumor biology and patient prognosis.

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High-grade glioma is a very aggressive and infiltrative tumor in which complete resection is a chance for a better outcome. We present the case of a 57-year-old man with a brain lesion suggestive of high-grade glioma. Brain MRI and F-fluorocholine PET/CT were performed previously to plan the surgery. Surgery was microscope assisted after the administration of 5-aminolevulinic acid. Postsurgery brain MRI and PET were blind evaluated to the surgery results and reported as probably gross total resection.

Gliomas are characterized by intratumoral histological heterogeneity, coexisting foci of low and high grade. First, in low-grade gliomas, neoangiogenesis has not yet developed and cellularity is low, so alterations on perfusion MRI may not be present. Second, a non-negligible number of high-grade gliomas show none, patchy, or weak contrast enhancement on MRI, so they can be misdiagnosed as low-grade glioma, preventing their correct management. We present 4 cases of patients in which 18F-fluorocholine PET defined the anaplastic tumor component and therefore the tumor aggressiveness, solving the limitations of MRI.

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder that causes CNS tumors in around 20% of patients, being pilocytic astrocytomas (PA), and particularly optic pathway gliomas (OPG), the most common. We present three cases of NF1 patients referred for 18F-fluorocholine PET/CT because of suspected glioma in the setting of ongoing FUMEGA (Functional and Metabolic Glioma Analysis) trial. One case turned out to be a WHO grade I ganglioglioma; the second was a high grade glioma; and the last one (negative in PET) a probable low-grade glioma.