NSCLC harbouring ALK rearrangement has a higher risk of developing brain metastases. Literature on MR Imaging radiogenomics (MRI-R) as predictors of ALK mutation is limited and less investigated. The aim of our study was to evaluate the semantic MRI-R parameters of NSCLC brain metastases and their correlation with ALK status.
We analyzed clinical data on 75 patients who were tested for ALK mutation and underwent MR imaging at diagnosis. Multiparametric MRI was performed in all cases. The associations between ALK mutation status and clinical features specifically age, sex, smoking, histology, TNM stage and imaging variables of brain metastasis, were analyzed using descriptive analysis (chi-square test) and univariate logistic regression analysis.
There were 46 ALK positive and 29 ALK negative cases that were subjected to MRI-R analysis. ALK positive were predominantly young (83%) and non-smokers (87%) (p < 0.001). Statistically significant difference (p < 0.001) was observed in lesion morphology and its T2W border, fuzzy and infiltrative border with hypointense peripheral solid rim in ALK positive while well defined border and no solid rim in ALK negative. Predominant signal on T1W imaging was hypointense (p < 0.001) in ALK negative, whereas heterogeneity was marker of ALK positive status on T1W (p < 0.001). Lesions in ALK negative group showed central restriction on DW images (p-0.001) and peripheral restriction of the solid rim was characteristic of ALK positive (p < 0.001). ALK positive showed thick ring enhancement while patchy enhancement favoured ALK negative. Incidence of meningeal involvement was significantly higher in ALK positive and was absent in 80% of ALK negative (p-0.02). On univariate logistic regression analysis, statistically significant association was found between age, smoking history, T2W lesion morphology, T2W border, restricted diffusion, enhancement and meningeal positivity (p < 0.05).
ALK positive brain metastases have peculiar MR imaging features that can be non-invasive diagnostic and predictive imaging biomarkers. MR radiogenomics have potential role in individualised management of ALK positive NSCLC brain metastasis.
IEC TMH.
Has not received any funding.
All authors have declared no conflicts of interest.