Background: This study aims to investigate the existence of any Diffusion Tensor Imaging
(DTI) value differences in Brain Metastases (BM) due to lung adenocarcinoma based on the
Epidermal Growth Factor Receptor (EGFR) gene mutation status.
Material and Methods: 17 patients with 32 solid intracranial metastatic lesions from lung adenocarcinoma
were included prospectively. Patients were divided according to the EGFR mutation
status as EGFR (+) (group 1, n:8) and EGFR wild type (group 2, n:9). The Fractional Anisotropy
(FA), apparent diffusion coefficient (ADC), normalized ADC (nADC), Axial Diffusivity (AD), and
Radial Diffusivity (RD) values were measured from the solid component of the metastatic lesions
and nADC values were calculated. DTI values were compared between group 1 and group 2. The
receiver-operating characteristic analysis was used to obtain cut-off values for the parameters presenting
a statistical difference between the EGFR gene mutation-positive and wild type group.
Results: There were statistically significant differences in measured ADC, nADC, AD, and RD
values between group 1 and group 2. The ADC, nADC, AD, and RD values were significantly
lower in group 1. There was no significant difference in FA values between the two groups. Analysis
by the ROC curve method revealed a cut-off value of ≤721 x 10-6 mm2/s for ADC (Sensitivity=
72.7, Specificity=85.7); ≤0.820 for nADC (Sensitivity=72.7, Specificity=90.5), ≤ 886 for AD
(Sensitivity=81.8, Specificity=81.0), and ≤588 for RD (Sensitivity=63.6, Specificity=90.5) in differentiating
EGFR mutation (+) group from wild type group.
Conclusion: A combination of the decreased ADC, nADC, AD, and RD values in BM due to lung
adenocarcinoma can be important for predicting the EGFR gene mutation status. DTI features of the
brain metastases from lung adenocarcinoma may be utilized to provide insight into the EGFR mutation
status and guide the clinicians for the initiation of targeted therapy.