Deoxyglucose uptake by a head and neck squamous carcinoma: influence of changes in proliferative fraction.

Abstract

Positron emission tomography, using the glucose analogue fluorodeoxy-D-glucose (FDG), is proving to be useful in the early response detection of head and neck tumors. Presently mechanisms underlying changes in FDG uptake after therapy are poorly understood. Response of tumors to therapy is often accompanied by a decrease in tumor cell proliferation. The purpose of this study was to assess whether or not changes in the uptake of deoxyglucose (DG) may reflect differences in proliferative fraction independent of other metabolic changes induced by using therapeutic agents. HN5 head and neck tumor cells were grown to different cell densities producing populations of cells with different proliferative indices without the need for exogenous agents to manipulate cell-cycle kinetics. (3)H-DG uptake, S-phase fraction (Spf), and lactate production were determined in each population of cells. Large differences in Spf between populations of cells were associated with differences in DG incorporation. Lactate production was also found to correlate strongly with DG uptake. Therapy-induced changes in FDG uptake by tumors may be partly due to changes in proliferation.