Cerebrospinal Fluid Liquid Biopsy Enables Targeted Therapy Without Tissue Diagnosis in Pediatric Low‐Grade Gliomas With BRAF V600E Mutation

We present two pediatric cases of pediatric low-grade gliomas (PLGG) with BRAF V600E mutations diagnosed and monitored using cerebrospinal fluid (CSF) liquid biopsy analyzed via digital droplet PCR (ddPCR), without tissue biopsy. Both patients were treated with dabrafenib and trametinib and monitored through clinical assessments, magnetic resonance imaging (MRI), and repeat CSF analyses. Both patients showed rapid and sustained clinical and radiological improvement following targeted therapy. In one case, follow-up CSF analysis 3 months post-treatment initiation was negative for BRAF V600E, indicating a potential role for liquid biopsy in monitoring treatment response. No significant toxicity was observed.