Lung cancer, with brain metastasis. Status post palliative radiotherapy in 2014 and status post 4 months erlotinib treatment for EGFR L858R mutation. Evaluate response. There is no intracranial mass or abnormal enhancement to suggest metastatic disease. Minimal enhancement along the frontal horn margins is favored to be vascular. There is no acute infarct or intracranial hemorrhage. No evidence of intracranial mass effect, midline shift, or herniation. Diffuse confluent T2-hyperintensity in the cerebral white-matter has not significantly changed since the previous examination and possibly reflect previous treatment. The ventricles remain enlarged as well as the other CSF-containing spaces, reflecting global brain volume loss.The major intracranial vascular flow voids remain preserved. Right mastoid fluid has improved since the previous examination. Left mastoid fluid remains minimal. There is no gross orbital abnormality.
1.No intracranial mass or abnormal enhancement to suggest metastatic disease are appreciated.2.Extensive cerebral white-matter abnormality is not significantly changed and compatible with posttreatment related change.