CHOLINE-CONTAINING COMPOUNDS IN HUMAN ASTROCYTOMAS STUDIED BY H-1-NMRSPECTROSCOPY IN-VIVO AND IN-VITRO

We have studied 14 patients with different grades of astrocytomas usin g H-1 NMR spectroscopy in vivo. Typically, astrocytomas exhibited a lo w N-acetyl-aspartate peak, a prominent signal from choline group-conta ining compounds, and lactate in the H-1 NMR spectra in vivo. The uncor rected choline/creatine + phosphocreatine peak area ratios were higher in tumors than in normal brain tissue. Absolute concentration of chol ine-containing compounds (1.74 +/- 0.09 mmol/L) in the normal brain ti ssue was not different in any grade of astrocytoma, but total creatine concentration in healthy brain (7.49 +/- 0.30 mmol/L) was higher than that in grade IV astrocytomas (4.84 +/- 0.89 mmol/L). Relaxation cons tants of choline-containing compounds did not differ in tumors from th ose determined in normal brain. Perchloric acid extracts of biopsy sam ples from 35 astrocytomas and 13 samples of normal temporal white matt er were analyzed with H-1 NMR. Total concentration of choline-containi ng compounds did not differ between controls and any grade of astrocyt oma when the quantification was done in vitro. It is interesting that phosphorylcholine concentration was about twofold greater in grade IV astrocytomas than in controls or other grades of astrocytomas. We conc lude that high phosphorylcholine in grade IV astrocytomas may be an in dicator of degree of malignancy. The proportional changes within the g roup of choline-containing compounds observed in vitro were not reflec ted in the NMR properties of choline signal in vivo.