Male, 49 years old, history of metastatic lung cancer to the brain status post radiation and multiple chemotherapy regimens, now status post two cycles of Alectinib. Innumerable T2 hyperintense, enhancing lesions are redemonstrated both supra- and infratentorially, most of which demonstrate some degree of hemosiderin staining. Since the prior examination, a majority of these lesions show a several-mm interval decrease in size both on post contrast and T2 weighted images. Some of the smaller lesions which were evident on the prior examination are no longer distinctly seen. No evidence of significant generalized mass effect is seen. No abnormal extra-axial fluid collections are detected. The ventricular system is stable in size and morphology.
A majority of the known innumerable brain metastases demonstrate an interval decrease in size on the order of several millimeters. Some of the smaller lesions which were evident on the prior examination are no longer clearly seen.