mutation positive NSCLC, CNS metastases, immunogenic tumour, tumor, TKI, IO, chemotherapy, radiation therapy, tumor biology, non-small cell lung cancer, brain metastases, SRS, radiation necrosis, lung molecular graded prognostic assessment, GPA, adenocarcinoma, ALK mutated NSCLC, ALK rearrangement, liquid biopsy, TKI generations, immunotherapy, crizotinib, alectinib, brigatinib, PFS, BICR, lorlatinib, ALK toxicities, survival rates, MRI features, RT, BBB, enhancing lesion, ALK/EGFR and NSCLC is a distinct biological subtype, sanctuary site, symptomatic and progressive brain mets, avoid WBRT, prefer SRS/SRT, asymptomatic BM, gefitinib, erlotinib, afatinib, icotinib, osimertinib