Fig 9.

DCE perfusion in pseudoprogression and progressive disease. A, Axial contrast-enhanced T1-weighted image and the corresponding permeability curve show an enhancing lesion that developed after radiation therapy and temozolomide in a 46-year-old patient with multicentric GBM (same patient as presented previously). The DCE perfusion of the temporal lesion (green ROI, 4) shows slowly progressive accumulation of gadolinium in the extravascular space, as shown in the graphic (green curve, 4), which is consistent with predominance of radiation injury within the lesion (pseudoprogression). The ROIs in the vessel (purple ROI, 5) and in normal white matter (purple ROI, 6) are obtained for comparison. B, Axial contrast-enhanced T1-weighted imaging and the corresponding permeability curve show an enhancing lesion in a 65-year-old patient with a previously resected GBM, who developed an enhancing lesion in the surgical bed (green ROI, 5) after radiation therapy and temozolomide. DCE perfusion shows a fast ascension curve, which implies a highly vascular lesion (green curve, 5), indicating predominance of malignant cells within the lesion (progressive disease).