Male, 54 years old, with GBM status post subtotal resection and adjuvant RT/TMZ. Again seen are findings reflective of craniotomy involving the right frontoparietal region. A small resection cavity is seen within the right frontal lobe, subjacent to the craniotomy, which has decreased in size relative to the prior examination. The degree of T2 hyperintensity within and around this cavity, including hyperintensity involving the adjacent cortex, is stable to slightly improved. The cavity is mildly hemosiderin stained and shows mild thin peripheral enhancement.A second craniotomy is also seen more posteriorly within the right parietal bone. Subjacent to the craniotomy, there is a peripherally enhancing, centrally T2 hyperintense lesion which has expanded in size since the prior examination, now measuring 27 x 24 mm, previously 19 x 16 mm. Perfusion imaging shows patchy elevated rCBV corresponding to some but not all of the enhancing rim of this lesion. The degree of surrounding T2 hyperintensity has expanded relative to the prior examination now encompassing most of the parietal lobe, part of the frontal lobe, and a small part of the temporal lobe.No additional lesions are seen. The right lateral ventricle is somewhat more effaced than on the prior examination due to progressive edema in the right parietal lobe, but otherwise the ventricular system is within normal limits.
1. A peripherally enhancing lesion within the right parietal lobe has increased in overall dimensions with an associated increase in the degree of surrounding parenchymal T2 signal abnormality likely representing edema. Perfusion assessment of this lesion is equivocal in that some parts of the enhancing rim correlate with elevated rCBV while other parts do not. The differential must therefore include both pseudoprogression and true progression. Close interval follow up is suggested.2. A resection cavity in the right frontal lobe has decreased in size. T2 signal abnormality around this cavity, including signal which involves the adjacent brain cortex, is stable to slightly reduced. A thin rim of enhancement around this cavity persists, but again, is overall smaller than on the prior exam.