Identification of Early Response to Anti-Angiogenic Therapy in Recurrent Glioblastoma: Amide Proton Transfer–weighted and Perfusion-weighted MRI compared with Diffusion-weighted MRI

= .04). Conclusion Early reduction in mean amide proton transfer signal intensity at 4-6 weeks after initiation of antiangiogenic treatment was predictive of a better response at 12 months and longer progression-free survival in patients with recurrent glioblastoma, especially in those with diffuse nonenhancing progression.