Glucose metabolites, glutamate and glycerol in malignant glioma tumours during radiotherapy.
OBJECTIVE
The metabolism of malignant glioma was studied in 13 patients. The main objective was to perform a study of the metabolic pattern of glucose, lactate, pyruvate, glutamate and glycerol in tumour tissue during base-line conditions and to detect any changes in the metabolism during radiotherapy.


METHODS
During a stereotactic biopsy, two microdialysis catheters were implanted: one in tumour and one in peri-tumoural tissue. Fasting samples were analysed daily, before and during 5 days of radiotherapy given with 2 Gy fractions.


RESULTS
Base-line levels of glucose and pyruvate were significantly lower in tumour compared to peri-tumoural tissue (P = 0.04 and 0.023, respectively). The lactate/pyruvate ratio was significantly higher in tumour tissue (P = 0.022). In general, the levels of lactate, glutamate and glycerol were higher in tumour tissue, although not statistically significant. Further, we could not detect any significant changes during the 5 days of radiotherapy in any of the metabolites analysed.


CONCLUSIONS
Radiotherapy up to 10 Gy given in five fractions does not influence the glucose metabolism nor does it induce any acute cytotoxic effect detected with glutamate or glycerol in malignant glioma, as assessed by microdialysis. The study confirms the glycolytic properties of glucose metabolism in malignant glioma.
Tabatabaei
Pedram
P
Department of Neurosurgery, Umeå University Hospital, 901 85 Umea, Sweden. pedram.tabatabaie@vll.se
Bergström
Per
P
Henriksson
Roger
R
Bergenheim
A Tommy
AT
D001932:Brain Neoplasms / Q000378:metabolism* / Q000532:radiotherapy / Q000601:surgery; D005910:Glioma / Q000378:metabolism* / Q000532:radiotherapy / Q000601:surgery; D005947:Glucose / Q000378:metabolism / Q000528:radiation effects*; D018698:Glutamic Acid / Q000378:metabolism / Q000528:radiation effects*; D005990:Glycerol / Q000378:metabolism / Q000528:radiation effects*; D006801:Humans; D017551:Microdialysis; D016634:Radiosurgery
D018698:Glutamic Acid; D005947:Glucose; D005990:Glycerol