Male, 57 years old, with metastatic limited to the brain status post whole brain radiotherapy, currently on PD1 antibody. Multiple supratentorial and infratentorial lesions are redemonstrated, all of which have decreased in size since the prior examination. In addition, whereas on prior exams these lesions were enhancing, they are no longer clearly enhancing but rather demonstrate intrinsic T1 hyperintensity, potentially related to melanin and/or mineral deposition, less likely blood product. Mild edema surrounding several of these lesions has improved or resolved, and none induces significant mass effect. No new intracranial lesions are seen. No new areas of parenchymal signal abnormality are detected. The ventricles are normal in size and morphology. No abnormal fluid collections are identified.
Continued response to therapy is seen with further decrease in the size of multiple supratentorial and infratentorial lesions. In addition, these lesions are no longer frankly enhancing but instead are intrinsically T1 hyperintense likely representing a treatment effect. No new intracranial lesions are seen.