Headache and vision changes. Evaluate for radiation necrosis versus tumor recurrence. MRI Brain: There is no significant interval change in size of the irregular enhancement in the site of the previous resection cavity and along the surgical tract in the left occipital lobe. However, the intensity of enhancement is reduced. There is unchanged extensive associated T2/FLAIR hyperintensity surrounding the resection cavity, with predominantly white matter involvement. There is associated mass effect on the left lateral ventricular atrium. No midline shift. No additional enhancing lesions are noted.MR Spectroscopy: Single voxel spectroscopy was performed at several points within the enhancing lesion. These demonstrate reduction in all major metabolic peaks as well as the presence of some lactate, with the exception of one sampled voxel, where the choline peak is slightly larger than that seen in the other sampled areas. This is believed to be technical and related to the larger size of the voxel of that sample. Multivoxel spectroscopy shows overall decrease in metabolites through the area of enhancing tissue with the exception of one or two sampled areas, where there is a minimally elevated choline peak, still below that of creatine, versus normal appearing tissue.MR perfusion: There is decreased relative cerebral blood volume in the area of question in the left occipital lobe, inclusive of the enhancing tissue and the presumed edema.
Conventional imaging demonstrates stable to slightly decreased size of an irregular enhancing lesion in the left occipital lobe. Perfusion imaging supports a benign process. Overall, spectroscopic evaluation is also most suggestive of a benign process. Close interval followup suggested. 