Perfusion and metabolism in predicting the survival of patients with cerebral gliomas

Abstract

Background. Noninvasive measurements of cerebral circulation and metabolism may be useful for diagnosis in patients with brain tumors. The authors tested the prognostic significance of circulatory and metabolic values or ratios determined by positron emission tomography (PET) in patients with gliomas. Methods. The subjects were 23 patients, who underwent a complete PET study of cerebral circulation and metabolism with long‐term follow‐up of at least 57 months. Regional cerebral blood flow (rCBF), blood volume (rCBV), oxygen extraction fraction, and the metabolic rates of oxygen (rCMRO2) and glucose (rCMRGl) were measured before treatment. Data regarding tumors, the contralateral gray matter and white matter, and the ratio between tumor and gray matter or between tumor and white matter were compared with survival time from the time of the PET study. Prognostic factors were tested using Cox's regression analysis. Results. Among clinical parameters, histologic grade and performance status were important variables regulating survival. When survival times of patients with values or ratios equal to or higher than the median were compared to those of patients with values or ratios lower than the median, significant determinant PET measurements were tumor rCMRGl and the ratios of tumor:gray rCMRGl and tumor:white rCMRGl. Median survival time in the patients with an rCMRGl value of 4.4 mg/100 ml/minute (median value) or more indicated 9 months, which was significantly shorter than greater than 113 months in the patients with a value lower than the median (P = 0.003 by the generalized Wilcoxon test). Patients with a higher value of gray rCBF, rCBV, or rCMRO2 had significantly longer survival times than those with a lower value. Conclusions. Cerebral circulation and metabolism as determined by PET can be of ancillary significance in predicting the prognosis of patients with gliomas.

Surgical Decision for Adult Optic Glioma Based on {18F]Fluorodeoxyglucose Positron Emission Tomography Study-Case Report-

“…[ 18 F]FDG uptake in gliomas is related to the degree of histological malignancy, and is a predictor of survival time. 10) In the present case, high uptake of [ 18 F]FDG indicated a malignant lesion at the first operation. However, the interval from initial symptoms to death was about 7 years, and the remaining eye kept useful visual acuity despite hemianopsia, suggesting that the tumor had undergone malignant transformation.…”

Effects of radiotherapy after hyperbaric oxygenation on malignant gliomas

“…In a recent study, Helmlinger et al (1997) measured PO 2 using a phosphorescence quenching microscopy technique in human tumour xenografts, and reported that hypoxic (≤ 5 mmHg) and near anoxic values (0-0.5 mmHg) were reached 70-80 and ≥ 150 µm away from tumour vessels respectively. However, a few histological studies on malignant gliomas have failed to obtain a certain tendency of tumour vascular density (Yoshii and Sugiyama, 1988;Stewart et al, 1991;Wesseling et al, 1994), although blood flow is lower in malignant gliomas than in normal white matter (Ito et al, 1982;Tyler et al, 1987;Mineura et al, 1994). These conflicting observations support the hypothesis that tumour tissue perfusion is incomplete due to transient (acute hypoxia) or partial occlusion of vessels (Chaplin et al, 1986).…”

“…Because oxygen consumption is lower in malignant gliomas than in the normal brain (Ito et al, 1982;Tyler et al, 1987;Mineura et al, 1994), tumour hypoxia is induced by low tumour blood flow. Radioresistance caused by hypoxia is thought to develop by two major mechanisms: diffusion-limited or chronic hypoxia, due to reduced oxygen diffusion to regions distant from the tumour vessels (Thomlinson and Gray, 1955), and acute hypoxia caused by transient occlusion of vessels (Chaplin et al, 1986).…”

“…Many investigators have reported that metabolism in malignant gliomas is anaerobic and that the oxygen consumption rate is lower in the tumour than in normal white matter (Ito et al, 1982;Tyler et al, 1987;Mineura et al, 1994). Normal brain PO 2 has been noted to decrease quickly after HBO exposure in animal experiments (Jamieson and van den Brenk, 1963).…”

Prognostic significance of parameters derived from co-registered18F-fluorodeoxyglucose PET and contrast-enhanced MRI in patients with high-grade glioma

“…The glucose metabolic rate of such tumours has been shown to be an accurate predictor of histological tumour grade as well as of patient survival, information that often effects management [8][9][10]. Although it was first demonstrated in the de novo evaluation of such tumours, there is some evidence that this relationship might also apply in the setting of prior therapeutic intervention [11,12].…”