Comparison of [14C]-deoxyglucose metabolism and peripheral benzodiazepine receptor binding in rat C6 glioma

A rat C6 glioma tumor model has demonstrated that C6 tumor cells express a high density of peripheral benzodiazepine (BDZ) receptors. We report a poor correlation between the density of peripheral BDZ receptors and tumor metabolism using [14C]-deoxyglucose in this C6 glioma model. We also compared the abilities of in vivo and in vitro BDZ receptor binding and tumor metabolism to measure the tumor area. All imaging methods were capable of estimating both the gross and total tumor area and had similar specificities and sensitivities. Because of a high signal-to-noise ratio, in vivo peripheral BDZ receptor binding may be a useful method for determining tumor size in human tumors expressing the receptor using PET