Fig 2.

A 73-year-old woman with EGFR-mutated NSCLC, which was initially treated with erlotinib for 9 months with an initial partial response of the primary lung tumor. The patient’s primary lung tumor then progressed, and the patient developed brain metastases. Repeat genetic analysis showed that the patient’s tumor now had a T790M mutation, so she was started on osimertinib. Images captured before (A–C) and 6 weeks after starting treatment with osimertinib (D–F) demonstrate a partial response to therapy of the left temporal (A and D), left frontal (B and E), and right occipital (C and F) enhancing brain metastases (arrows).