Adjuvant Treatment of ALK-positive Non-small Cell Lung Cancer with Ensartinib Guided by MRD

Patients will receive Ensartinib 225mg QD by MRD test guided, if MRD test shows negative, only ensartinib will be given. if MRD test turns from negative to posive, patients will receive step-up treatment, which is ensartibe plus platinum - based doublet chemotherapy no more than 4 cycles. If MRD test turns from posive to negative, only ensartinib will be given. if MRD test constantly shows positive, MDT will determine the next step ensartib-based therapy.