Male, 79 years old, with neuroendocrine lung cancer metastases to the brain, status post whole brain RT, follow-up exam. At least five enhancing lesions are redemonstrated scattered throughout both cerebral hemispheres. Since the prior examination, all of these lesions demonstrate a very slight, 1 to 2 mm increase in overall size. For example. The dominant left frontal lobe lesion now measures 15 x 14 mm, previously 14 x 13 mm. This lesion also demonstrates a more conspicuously rim-enhancing morphology.It is difficult to determine if any of these lesions exert local edema because there has been a substantial progression in bilateral white matter T2 hyperintensity likely reflecting treatment related change. However, no significant generalized mass effect is observed. No new lesions are detected. The ventricles are stable and normal in size.
The previously demonstrated scattered enhancing lesions are again seen in both cerebral hemispheres, all showing a slight interval increase in size. As this is the first posttreatment examination, it is possible that this change may represent reaction to radiotherapy. Findings on subsequent follow-up examinations will more accurately assess for the possibility of tumor progression. No entirely new lesions are seen, and there is no evidence of any significant generalized mass effect. Progressive generalized white matter signal abnormality likely represents treatment related change.