Preliminary study of metabolic changes in brain glucose of patients with lung adenocarcinoma

Abstract

Objective To investigate the metabolic changes in the resting brain glucose of patients with different stages of lung adenocarcinoma but without brain metastasis. Methods A total of 120 patients with primary untreated and histologically confirmed lung adenocarcinoma were divided into four groups based on TNM staging: stage I, 28 cases; stage II, 29 cases; stage III, 31 cases; and stage IV, 32 cases. The whole-body 18F-FDG PET/CT images of the patients were retrospectively analyzed. The brain PET data of the four groups were also examined individually and compared with those of the 50 healthy controls. Moreover, the metabolic changes in the brain glucose of the four groups were compared. Results The brain PET images showed relative reductions of the regional cerebral resting glucose metabolism of all the groups. In the stage I group, the reductions were mainly observed in the left superior-middle frontal, right superior-middle temporal, and left middle-inferior temporal gyrus. The total voxel value for this group was 681. The reductions in stage II group were evident in the left superior-middle frontal, right superior-middle temporal, and left middle-inferior temporal gyrus. The total voxel value for the stage II group was 1258. In the stage III group, reductions were evident in the left superior-middle frontal, right superior-middle temporal, left middle-inferior temporal gyrus, and right inferior parietal lobule. The total voxel value for the stage III group was 1810. In the stage IV group, reductions were evident in the left superior-middle frontal, right superior-middle-inferior temporal, left superior-middle-inferior temporal gyrus, right inferior parietal lobule, left anterior cingulated, and right insula gyrus. The total voxel value for the stage IV group was 2910. The four groups showed significantly different voxel values in their hypometabolic brain area (F=25.444, P=0.000 1) , and the ranges expanded with tumor stage progression. Conclusions The reduced metabolic cerebral regions in lung adenocarcinoma patients involved a number of functional regions related to mood disorders. The ranges of the metabolic changes in the resting brain glucose in lung adenocarcinoma patients were closely correlated to different tumor stages. Key words: Fluorodeoxyglucose F18; Adenocarcinoma, lung; Positron-emission tomography; Tomography, X-ray computed; Brain glucose metabolism; Statistical parametric mapping