Fig. 2.

The detection of ctDNA at baseline and the correlation between overall survival and baseline CSF ctDNA positivity. A Positive detection rates of somatic mutations in CSF, plasma, and tissue samples. P-values were calculated using the Fisher’s exact test. B The distribution of max VAF of the three sample types. P-values were calculated using an unpaired two-tailed t-test. C Overall survival of patients with positive and negative CSF ctDNA detection at baseline. P-values were calculated using the log-rank test. Abbreviations: CSF, cerebrospinal fluid; ctDNA, circulating tumor DNA; HR, hazards ratio; VAF, variant allele frequency