Fig. 6: MRI scans, CSF cytology and ctDNA analysis of patients with LM with failed treatment responses to third-generation EGFR-TKIs at different clinical time points.

a Dynamic changes in MRI scans, CSF cytology and ctDNA. b Dynamic changes in the allele frequency of various mutations detected in serial CSF samples. MRI magnetic resonance imaging, CSF cerebrospinal fluid, ctDNA circulating tumour DNA, LM leptomeningeal metastasis, EGFR epidermal growth factor receptor, TKI tyrosine kinase inhibitor.