Female, 68 years old, with GBM status post RT/TMZ. The prior MRI was the post RT exam with question of pseudoprogression. Patient is MGMT promotor unmethylated. A heterogeneous lesion is again seen involving the left inferior and middle frontal gyri with evidence of prior biopsy or partial resection. Nodular enhancement is again seen at the operative site, along with a rim-enhancing lesion located deep to the operative site within the left centrum semiovale. The superficial enhancement is relatively unchanged from the immediate prior examination. The deeper centrum semiovale enhancement, however, has increased in size by 1 or 2 mm. The areas of enhancement correlate with mildly elevated rCBV which appears to be less than that seen on the prior examination.Confluent fairly extensive FLAIR hyperintensity surrounding the above-mentioned lesions has mildly progressed extending through the left frontal and anterior parietal parenchyma as well as the operculum. However, there is only minimal associated mass effect. This area of signal abnormality correlates with low rCBV.Ill-defined periatrial T2 hyperintensity and scattered more focal T2 hyperintense lesions within the cerebral white matter, show no significant interval change. This includes a small focus of signal abnormality corresponding to the right corticospinal tract within the pons. No new pathologic intracranial enhancement is seen. Ventricles remain normal in size and morphology.
Enhancing lesions within the left frontal lobe are redemonstrated. The more superficial lesion demonstrates no significant change in size while the deeper rim-enhancing lesion has increased in size but only by 1 or 2 mm. Both areas of enhancement correlate with mildly elevated rCBV which appears reduced from the prior examination. FLAIR hyperintensity surrounding these lesions has increased but with only minimal mass effect.One possible interpretation of these findings is that the areas of enhancement represent partially treated tumor while the more extensive FLAIR abnormality may reflect pseudoprogression. Ultimately, both viable tumor and treatment effect remain in the differential, though the slowed expansion of enhancement is somewhat encouraging. 