The Dynamic Monitoring of Cerebrospinal Fluid ctDNA

The efficacy of Furmonertinib combined with OMMAYA lateral ventricle chemotherapy (pemetrexed) was evaluated once a week during the treatment phase. After the brain lesions were evaluated as CR, the drug holiday study phase was added. During the study period, the patients were followed up once a week until the investigators deemed the subjects unfit to continue to participate in the study or the efficacy was evaluated as disease progression (PD).