MATERIALS AND METHODS

nant tissue is due to the enhanced rate ofglucose utilization by neoplastic cells (5—7).Due to increased metabolic de mand for glucose, the hexokinase (a key enzyme for gly colysis) activity is increased (8). 2-Deoxyglucose has been shown to be a substrate for hexokinase (9). Therefore, the 2-deoxyglucose analog [18flfl) ( is a particularly appro priate imaging agent for tumors. Clinical applications using positron emission tomography (PET) have been reported on the correlation ofthe [‘8F]FDGuptake to: the differentiation of malignant tumor from benign (10); the grade of malignancy (11); and the proliferative activity of tumor cells (12). An autoradiographic study using x-ray films has also reported that ‘8F-FDG @ accumulates into areas of malignant growth (13). Hig