we have shown previously that a11 cells show higher glyco lytic activity and s2 cells higher oxygen consumption and lower glyco lytic activity, and demonstrated this in the corresponding xenografts using deuterium magnetic resonance spectroscopy and spectroscopic imaging measurements of deuterium - labelled glucose metabolism in vivo. treatment of cells with azd2014 ( mtor1 and mtor2 inhibitor ), imatinib ( pdgfr; tyrosine kinase inhibitor ) and gefitinib ( egfr; tyrosine kinase inhibitor ) showed that cell viability was correlated with metabolic phenotype, where oxidative cells were more drug resistant ( extended data fig. 8f – h ). the concentrations of unlabelled serine, threonine, glutamine and glutamate were significantly higher in oxidative regions in the patient tumour sections ( anova, tukey ’ s p < 0. 05 ), and in the neurospheres, the concentrations of unlabelled leucine / isoleucine, glutamine, glutamate, histidine and phenylalanine were significantly higher ( anova, tukey ’ s p < 0. 005 ) ( extended data fig. 9 ). the oxidative phenotype in gb has been associated with increased fatty acid oxidation, and we observed that the concentrations of unlabelled fatty acids were higher in the more glyco lytic regions in both the human and neurosphere data, as were intermediates in the pentose phosphate pathway. the extent to which tumour metabolism is driven by cell - intrinsic mechanisms or microenvironmental pressures is an open question in tumour biology. to address this question, we measured the metabolic activity of gb within its native microenvironment using ms imaging of isotope labelling in rapidly quenched tissue from patients with gb. a similar approach has been used to map heterogeneity in fatty acid synthesis in gliomas implanted orthotopically in mice, to map metabolic activities in kidney and brain in mice and to image glyco lytic activity in a lung metastasis model. using a targeted approach, we identified distinc t glyco lytic and oxidative metabolic phenotypes. although recent reports have identified metabolic phenotypes from a transcriptomic analysis, we describe here the classification of metabolic phenotypes based on measurements of metabolic activity in patient tumours in vivo at relatively high spatial resolution ( 65 μm ). the metabolic phenotypes occupied distinc t territories that did not show significant differences in the cellular composition of their microenvironments, including immune cell infiltration, proliferative index and vascularization. the presence of these metabolic phenotypes in distinc t territories and their cellular composition was confirmed by spatial transcriptomics. importantly, we have shown that these tumour - cell - intrinsic metabolic phenotypes can be independent of the tme. previous studies have also shown that tumour subtype - specific protein and gene expression profiles can be independent of the tumour niche. we observed no change in lactate and glutamate labelling with distance from the blood vessels. this appears to be inconsistent with a study in an orthotopically implanted glioma cell line model ( u87mg ) in immunocompromised mice that showed high mitochondrial activity in cells adjacent to vessels and increased expression of hypoxia - related genes at increasing distance from the vessels. however, there were no significant increases in lactate concentration or differences in α - ketoglutarate concentrations in the cells with distance from the vessels in this study, although these concentrations may have been affected by the flow cytometric method used to sort the cells. an msi study on an orthotopically implanted syngeneic murine model of isocitrate dehydrogenase 1 mutant gb in animals fed for 48 h with [ u - c ] glucose showed a remarkable degree of metabolic homogeneity in the tumours, in contrast to what was observed here in tumours from patients with gb, emphasising the significance of the observed metabolic phenotypes. the cell - intrinsic nature of the metabolic phenotypes was confirmed using neurospheres grown in vitro, which reproduced the metabolic phenotypes observed in the patients and were preserved following their orthotopic implantation in rats. exposing the neurospheres to chronic hypoxia did not lead to significant changes in the neurosphere transcriptomes, demonstrating the robustness of these phenotypes and further underlining their independence from the tme. this is in contrast to a similar study in patients with lung cancer who were infused with [ u - c ] glucose, which concluded that given the observed differences in glucose oxidation in the tca cycle in well - perfused versus poorly perfused regions, tumour perfusion in this case overrides tumour - cell - intrinsic metabolic phenotypes. a recent study in mouse models of leukaemia, pancreatic, lung and colon cancer showed that these tumours suppress tca cycle activity relative to normal tissue. by contrast, the glutamate labelling observed here in the gb tumours was similar to that in normal - appearing brain. similar observations of substantial glucose oxidation in the tca cycle have been made previously in human lung tumours and in non - imaging studies of patients with gb who were infused with [ u - c ] glucose. metabolic phenotypes with distinc t therapeutic vulnerabilities have been identified in several cancers, including gb, in which gb cells with an oxidative phenotype were shown to be more sensitive to inhibitors of mitochondrial complex i and to radiation treatment. we have shown previously that s2 cells are more sensitive to irradiation in vitro and in vivo and have shown here, and previously, that they have a more oxidative phenotype with higher tca cycle activity than a11 cells, which show a more glyco lytic phenotype. previous rna sequencing studies have shown that a11 has a mesenchymal phenotype, whereas s2 cells have a neural progenitor cell - like phenotype, consistent with a previously identified association between the mesenchymal and glyco lytic phenotypes. cells displaying these distinc t metabolic phenotypes occupy territories that are sufficiently large to be imaged clinically using techniques such as hyperpolarized c magnetic resonance imaging ( mri ) and deuterium metabolic imaging. these metabolic phenotypes show a correlation with treatment responsiveness, suggesting that a personalized therapy approach may be possible in which metabolic imaging and phenotyping could be used to guide subsequent treatment selection. we have demonstrated here high - resolution imaging of isotope labelling of cellular metabolites in a human tumour in vivo. in conjunction with studies on patient - derived neurospheres and orthotopically implanted xenografts, we have demonstrated the presence of different metabolic phenotypes within gb that are tumour - cell - intrinsic and largely independent of the tme. three male patients from addenbrooke ’ s hospital, cambridge, were infused with [ u - c ] glucose. the selection criteria included first clinical presentation, mri consistent with gb and no significant co - morbidities. following induction of anaesthesia, a pyrogen - free 5 % solution of [ u - c ] glucose in sterile saline ( merck ) was administered as a bolus of 8 g over 10 min followed by 8 g h continuous infusion, as described previously for patients with gb and several other tumour types. arterial blood was collected by a peripheral arterial line before bolus administration and then every 15 min following the start of infusion and at 15 min after the end of the infusion. tumour sampling was guided by intra - operative stealth navigation and assessment of 5 - ala fluorescence. tumours were sampled between 90 and 150 min. a pituitary ronguer was used to transfer tumour samples directly into liquid nitrogen. the freezing time was < 5 s between tissue devascularization and immersion in liquid nitrogen.