Male, 72 years old, with left frontotemporal GBM status post biopsy then radiotherapy which was completed in 6/2016. Evaluate for progression/response. Postoperative findings are seen compatible with a left parietal approach stereotactic biopsy. Again seen is an irregularly marginated enhancing lesion which spans the left frontal operculum, insula, sylvian fissure and perhaps the temporal. Since the pretreatment evaluations, the superior portion of the lesion has become more centrally necrotic while the enhancing medial rim seems to have thickened. The overall size of this component has increased with an AP dimension of up to 5 cm, previously 3.5 cm. The more inferior portion of the lesion which involves the insula and temporal lobe has also become centrally necrotic and perhaps minimally larger. There may be some subarachnoid spread from the lesion into the sylvian fissure. The enhancing portions of the lesion correlate with clear elevated rCBV.Surrounding T2 hyperintensity within the left cerebral hemisphere has increased in geographic extent. The degree of generalized mass effect has also increased with progressive effacement of the left lateral ventricle and a midline shift to the right of 11 mm, previously about 6 mm. The right lateral ventricle has increased in caliber suspicious for entrapment.Periventricular T2 hyperintensity is seen on the right along with a few scattered nonspecific foci of FLAIR hyperintensity. No definite evidence of contralateral tumor spread is seen. The core of the tumor demonstrates susceptibility compatible with blood product. However, no frank intracranial hematoma is identified.
Since the prior pretreatment examinations, the overall size of the patient's left frontotemporal tumor has increased. While this at least partly represents development of central necrosis, which could reflect response to treatment, areas of progressively thicker rim enhancement are also seen. There is also a generalized increase in mass effect with progressive midline shift to the right and developing entrapment of the right lateral ventricle. Overall, the findings are concerning for progressive tumor with perhaps a minor component of treatment effect.