Success of Crizotinib Combined with Whole-Brain Radiotherapy for Brain Metastases in a Patient with Anaplastic Lymphoma Kinase Rearrangement-Positive Non-Small-Cell Lung Cancer

Although crizotinib shows marked antitumor activity in anaplastic lymphoma kinase (ALK) rearrangement-positive non-small-cell lung cancer (NSCLC) patients, all treated patients ultimately develop resistance to this drug. Isolated central nervous system failure without progression at extracranial sites is a common progression pattern in ALK rearrangement-positive NSCLC patients treated with crizotinib. Here, we report the success of crizotinib combined with whole-brain radiotherapy in an ALK rearrangement-positive NSCLC patient who developed leptomeningeal carcinomatosis and progression of multiple brain metastases. Additionally, we focused on the mechanism involved by examining the plasma and cerebrospinal fluid concentrations of crizotinib in the present case.