Fig 1.

Examples of measurable and nonmeasurable disease, according to the RANO criteria. A, Axial contrast-enhanced T1-weighted image shows a heterogeneously enhancing lesion in the left parietal lobe (arrows), corresponding to recurrent GBM, with both perpendicular measurements of >10 mm, thus representing measurable disease. The more commonly seen examples of nonmeasurable disease are represented in the axial T2 image (B), depicting a hyperintense infiltrating lesion in the left parieto-occipital region (arrowheads) in a patient with anaplastic astrocytoma. The axial contrast-enhanced T1-weighted image (C) shows a subcortical enhancing nodule representing a recurrent GBM (arrow), in which perpendicular diameters are <10 mm. The axial contrast-enhanced T1-weighted image (D) shows residual tumor in the resection cavity of a partially resected GBM (curved arrow), which has poorly defined margins.