Reason: GBM. s/p short course RT. Now on TMZ (7 day on/7 day off). MGMT promoter methylated. Diplopia since craniotomy. Brain: Per technologist note, patient had difficulty tolerating the study and was combative. Examination is very motion degraded.Again seen are postsurgical changes of suboccipital craniotomy for resection of posterior fossa tumor. Compared to 4/14/2016 and 2/19/2016, there is further mild increase in FLAIR hyperintensity surrounding the resection cavity including the cerebellar vermis and right greater than left cerebellar hemispheres. There is also slight increase in heterogeneously enhancing tissue surrounding the resection cavity. Partial effacement of the fourth ventricle is again seen. Ventricles remain not significantly changed in size with mild prominence, likely related to volume loss, also not significantly changed. No new lesions are seen elsewhere in the brain. A nonspecific focus of T2 hyperintensity within the white matter adjacent to the left frontal horn is unchanged. No evidence of significant intracranial mass effect, midline shift, or herniation. Orbits: Bilateral lens implants. No abnormal mass or definite abnormal enhancement is seen in the orbits. There is minimal asymmetric enhancement surrounding the left optic nerve sheath which is of uncertain significance. The optic nerves themselves are normal in size and signal intensity, and are symmetric bilaterally. No retrobulbar mass, chiasmatic mass, or parasellar abnormality is seen. Extraocular muscles are unremarkable. Mild scattered paranasal sinus opacification.
1. Examination is significantly motion degraded. Compared to 4/14/2016 and prior, there is slight further increase in FLAIR hyperintensity and enhancement surrounding the cerebellar resection cavity. Given the recent time period since treatment and MGMT promotor methylation status, post-treatment change still remains a reasonable possibility. Recommend continued close follow up.2. Orbit MRI is essentially unremarkable. There is mildly increased enhancement/vascularity surrounding the left optic nerve sheath which is of uncertain significance.