QUANTITATIVE PROTON SPECTROSCOPY AND HISTOLOGY OF A CANINE BRAIN-TUMOR MODEL

Quantitative, single voxel proton nuclear magnetic resonance (NMR) spe ctroscopy and histological analysis was performed in eight dogs implan ted with the transplantable canine glioma model of Wodinsky (Proc. Am. Assoc. Cancer Res. 10, 99 (1969)). Signals from choline, creatine, N- Acetyl Aspartate (NAA) and lactate were converted to molar concentrati on units and correlated with the quantitative analysis of histological ly determined tissue types within the localized volume selected for NM R spectroscopy. In general, compared with normal brain, the lesions we re associated with reductions in all metabolite concentrations, with t he exception of lactate, which was increased. NAA and creatine decreas es were most significantly correlated with the total lesion volume (P < 0.01), suggesting that these compounds are present in normal brain o nly. Changes in choline levels did not correlate strongly with any par ticular tissue type. Lactate was found to increase with increasing tot al lesion volume (P < 0.01), but not with increasing percent tumor, su ggesting that it accumulates in abnormal tissue other than the tumor. The spectra reported were similar to those observed in human glioblast omas, with the exception that elevations of choline were not observed. The transplantable canine gliosarcoma system appears to be a suitable tumor model for evaluation by clinical radiological techniques such a s magnetic resonance imaging (MRI) and proton NMR spectroscopy.