Fig. 3: The unsupervised clustering of the deep learning features, the distribution of the EGFR-DLS, and two NSCLC adenocarcinoma patients with different EGFR mutation status.

a The unsupervised hierarchical clustering of the deep learning features (i.e., the output of global average pooling, N = 256) on the vertical axis, which shows a significant association of the deep learning expression patterns with EGFR mutation (training: p < 0.001, validation: p < 0.001, HMU: p = 0.002, χ² test). There was also significant association of the expression patterns by stage (training: p < 0.001, validation: p < 0.001, HMU: p = 0.66), smoke status (training: p < 0.001, validation: p < 0.001, HMU: p = 0.045), histology (training: p < 0.001, validation: p < 0.001, HMU: p = 1.00), and sex (training: p < 0.001, validation: p < 0.001, HMU: p = 0.076). b The EGFR-DLS distribution across different subgroups divided by EGFR mutation status and histology type. Significant difference of EGFR-DLS was found between adenocarcinoma (ADC) and squamous cell carcinoma (SCC) for EGFR-wild-type patients (training: p < 0.001, validation: p < 0.001, HMU: p = 0.24). In the box plots, the central line represents the median, the bounds of box the first and third quartiles, and the whiskers are the interquartile range. For statistical comparisons among different groups, a two-sided Wilcoxon signed-rank test was used. For the validation cohort, n = 80, 32, and 75 for EGFR− ADC, EGFR− SCC, and EGFR+ ADC groups, respectively. For the HMU test cohort, n = 22, 7, and 36 for EGFR− ADC, EGFR− SCC, and EGFR+ ADC groups, respectively. Note: ***means p value <0.001. If p value is otherwise it is so noted. c, d The patients with wild-type EGFR and EGFR L858 mutant, respectively. The first lines are the CT, PET, and fusion images of ¹⁸F-FDG PET/CT imaging, the second lines are the input ROIs. For the third line, columns 1 and 2 show two of the activation maps of the fourth ResBlock, columns 3 and 4 show the negative filter and positive filter. The fourth lines are the CT, PET, and fusion images of ¹⁸F-MPG PET/CT imaging. The last lines show hematoxylin and eosin (H&E) staining, the immunohistochemistry for total-EGFR, phospho-EGFR, and L858-specific EGFR at X20 magnification demonstrating EGFR mutation status. Scale bar, 200 µm. Immunohistochemistry scoring was performed on at least two independent biological replicates (slides) per patient.