We could demonstrate the increase of mutational DNA fraction of H3F3A K27M in the CSF and plasma in patients with a tumor progression in the MR images (Fig. 6a–d, Supplementary Fig. 8a–b, Supplementary Fig. 9) and partially decreased levels for BRAF V600E mutation during targeted drug treatment with trametinib and dabrafenib (Fig. 6b, Supplementary Fig. 10). Here, BRAF is linked to neoplasm.