1.A 48-year-old woman never smoker presents to her primary care physician with 3 months of a nonproductive cough and associated unintentional weight loss that has not subsided despite adequate antibiotic treatment for community-acquired pneumonia. A CT scan of the chest shows a right lower lobe 4.8 × 3.7 cm spiculated lung mass with associated mediastinal lymphadenopathy. The patient underwent endobronchial biopsy of the mass and mediastinal lymph nodes. Pathology is positive for adenocarcinoma of lung origin. EGFR mutational analysis from the tissue is positive for exon 19 deletion by next-generation sequencing. Brain MRI shows a single 1.3 × 1.7 cm right parietal lobe ring-enhancing lesion consistent with metastatic disease. The patient is without neurologic symptoms. What is the next step in the management?

A. Neurosurgical excision of the brain lesion

B. Stereotactic radiosurgery of the brain lesion

C. Platinum doublet combination

D. Erlotinib

E. Osimertinib