Moran Artzi1,
  2, Orna Aizenstein3, Deborah T. Blumenthal4,
  Felix Bokstein4, Benjamin W. Corn5, 6, Dafna
  Ben Bashat3
 1The
  Functional Brain Center, The Wohl Institute for Advanced Imaging , Tel Aviv
  Sourasky Medical Center, Tel Aviv , Israel; 2Sackler Faculty of
  Medicine, Tel Aviv University , Tel Aviv, Israel; 3The Functional
  Brain Center, The Wohl Institute for Advanced Imaging , Tel Aviv Sourasky
  Medical Center, Tel Aviv, Israel; 4Neuro-Oncology Service, Tel
  Aviv Sourasky Medical Center, Tel Aviv, Israel; 5Institute of
  Radiotherapy, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; 6Sackler
  Faculty of Medicine, Tel Aviv University , Tel Aviv , Israel
Following bevacizumab(BVZ) therapy in patients with glioblastoma (GB), a pattern of non-enhancing tumor progression was reported, characterized by areas with hyperintense T2-weighted signal. This study aimed to differentiate between the vasogenic and tumor components in these areas, based on diffusion and perfusion MRI. Thirteen GB patients were scanned before and during BVZ therapy (total 37 scans). Unsupervised segmentation was performed on the non-enhancing hyperintense FLAIR areas, clustering into: vasogenic edema, intermediate and active tumor. A decrease in vasogenic edema, along with a trend of increased tumor-related components was detected, supporting the concept of infiltrative tumor progression pattern following BVZ therapy.