Background
To develop and externally validate contrast-enhanced (CE) T1-weighted MRI-based radiomics for the identification of epidermal growth factor receptor (EGFR) mutation, exon-19 deletion and exon-21 L858R mutation with the spinal bone metastasis from primary lung adenocarcinoma.
Methods
The study enrolled 159 patients from our hospital between Jan. 2017 and Sep. 2021 to form a primary set, and 24 patients from another center between Jan. 2017 and Oct. 2021 to form an independent validation set. Radiomics features were extracted from the CET1 MRI using the Pyradiomics method. The least absolute shrinkage and selection operator (LASSO) regression was applied for selecting the most predictive features. Radiomics signatures (RSs) were developed based on the primary training set to predict the EGFR mutation and to differentiate the exon-19 deletion and exon-21 L858R. The RSs were validated on the internal and external validation sets using the ROC curve analysis.
Results
A total of 8, 3 and 5 most predictive features were selected to build the RS-EGFR, RS-19 and RS-21 for predicting the EGFR mutation, exon-19 deletion and exon-21 L858R, respectively. The RSs generated favorable prediction efficacies on the primary (AUCs, RS-EGFR vs. RS-19 vs. RS-21, 0.851 vs. 0.816 vs. 0.814) and external validation (AUCs, RS-EGFR vs. RS-19 vs. RS-21, 0.807 vs. 0.742 vs. 0.792) sets.
Conclusions
Radiomics features from the contrast-enhanced MRI could be used to detect the EGFR mutation, increase the certainty of identifying exon-19 deletion and exon-21 L858R mutations based on the spinal metastasis.