EGFR and lung carcinoma: Whether high-dose osimertinib is required to achieve intracranial concentrations sufficient to treat leptomeningeal disease has come into question as standard-dose osimertinib 80 mg daily has also shown activity in a retrospective series and may therefore represent a better-tolerated option.76 Collectively, these results suggest that osimertinib represents a potential radiation-sparing treatment option in patients with EGFR-mutant lung cancer metastatic to the leptomeninges.