Correlation Between 18F-FDG Uptake and Immune Cell Infiltration in Metastatic Brain Lesions

Young-Sil An; Se-Hyuk Kim; Tae Hoon Roh; So Hyun Park; Tae-Gyu Kim; Jang-Hee Kim

doi:10.3389/fonc.2021.618705

Correlation Between ¹⁸F-FDG Uptake and Immune Cell Infiltration in Metastatic Brain Lesions

Front Oncol. 2021 Jun 24:11:618705. doi: 10.3389/fonc.2021.618705. eCollection 2021.

Authors

Young-Sil An¹, Se-Hyuk Kim², Tae Hoon Roh², So Hyun Park³, Tae-Gyu Kim³, Jang-Hee Kim³

Affiliations

¹ Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, Suwon, South Korea.
² Department of Neurosurgery, Ajou University School of Medicine, Suwon, South Korea.
³ Department of Pathology, Ajou University School of Medicine, Suwon, South Korea.

Abstract

Background: The purpose of this study was to investigate the correlation between ¹⁸F-fluorodeoxyglucose (FDG) uptake and infiltrating immune cells in metastatic brain lesions.

Methods: This retrospective study included 34 patients with metastatic brain lesions who underwent brain ¹⁸F-FDG positron emission tomography (PET)/computed tomography (CT) followed by surgery. ¹⁸F-FDG uptake ratio was calculated by dividing the standardized uptake value (SUV) of the metastatic brain lesion by the contralateral normal white matter uptake value. We investigated the clinicopathological characteristics of the patients and analyzed the correlation between ¹⁸F-FDG uptake and infiltration of various immune cells. In addition, we evaluated immune-expression levels of glucose transporter 1 (GLUT1), hexokinase 2 (HK2), and Ki-67 in metastatic brain lesions.

Results: The degree of ¹⁸F-FDG uptake of metastatic brain lesions was not significantly correlated with clinical parameters. There was no significant relationship between the ¹⁸F-FDG uptake and degree of immune cell infiltration in brain metastasis. Furthermore, other markers, such as GLUT1, HK2, and Ki-67, were not correlated with degree of ¹⁸F-FDG uptake. In metastatic brain lesions that originated from breast cancer, a higher degree of ¹⁸F-FDG uptake was observed in those with high expression of CD68.

Conclusions: In metastatic brain lesions, the degree of ¹⁸F-FDG uptake was not significantly associated with infiltration of immune cells. The ¹⁸F-FDG uptake of metastatic brain lesions from breast cancer, however, might be associated with macrophage activity.

Keywords: 18F-fluorodeoxyglucose; brain metastasis; immune cell; positron emission tomography; tumor microenvironment.