Relationship with programmed cell death ligand 1 (PD-L1) and DTI features in brain metastases of non-small cell lung cancer; Preliminary study.

OBJECTIVES The purpose of the study was to determine DTI properties of brain metastases in subjects with non-small cell lung carcinoma (NSCLC), to evaluate whether there was a correlation between DTI findings and programmed cell death ligand-1 (PD-L1). METHODS The study population (n:22) was assigned to PD-L1 negative (Group 1: PD-L1 expression<%50) (n=11) or positive (Group 2: PD-L1 expression ≥%50) (n=11). We compared ADC and FA values measured from the enhanced solid metastases and peritumoral edema area with PD-L1 protein status. RESULTS The mean ADC values were lower in group 2 compared to group 1. The peritumoral ADC values were higher in group 2 compared to group 1. Mean peritumoral edema FA values are lower in group 2 compared to group 1. The peritumoral edema nADC values were higher in group 2 compared to group 1. As PD-L1 expression frequency increased, ADC values in the peritumoral edema area increased and FA values decreased. CONCLUSIONS We thought that the existence of PD-L1 protein doesn't affect ADC and FA values of brain metastasis (BM) originating from NSCLC. DTI characteristics of the peritumoral edema area could be a guide in determining PD-L1 protein status of brain metastases of NSCLC. The relationship between PD-L1 expression status and DTI features in BM from NSCLC could help us to have an idea in response to immunotherapy.