Evaluation of brain metabolism using F18-FDG PET/CT imaging in patients diagnosed with lung cancer.

OBJECTIVES

Brain imaging of regional metabolic changes in cancer patients can provide insights into cancer biology. We aimed to detect regional metabolic changes in the brains of untreated lung cancer patients without brain metastases using 2-deoxy-2-[18F]fluoroglucose PET/computed tomography.

METHODS

The study included 44 lung cancer patients and 17 non-cancer patients as controls. Standardized uptake value (SUV) mean values of 68 different brain regions were recorded, and their ratios to whole brain and brainstem SUVmean were calculated.

RESULTS

Comparisons between the groups showed significant reductions in the frontal lobe, inferior temporal gyrus, and right cingulate and paracingulate gyrus ratios in the patient group. Conversely, the right nucleus caudatus and right pallidum ratios were elevated. Correlation analysis with total lesion glycolysis (TLG) revealed positive correlations in the basal ganglia, right insula, amygdala, and right hippocampus ratios. Negative correlations were observed in the left frontal lobe and some temporal and parietal regions.

CONCLUSIONS

While most brain regions showed reduced metabolism, potentially due to tumor-brain glucose competition, others were preserved or positively correlated with TLG, suggesting a link to poor prognosis. The reduced metabolism in the frontal lobe might be associated with depression and cognitive decline in cancer patients.