P07.05 Intracellular pH measured by 31P MR-Spectroscopy predicts site of progression in recurrent glioblastoma under antiangiogenic therapy with bevacizumab

摘要

Purpose:In solid tumors, major changes in the expression and/or activity of plasma membrane ion pumps and transporters facilitate proton efflux and enable tumor cells to maintain a higher intracellular pH (pHi), while the microenvironment (pHe) is commonly more acidic compared to normal differentiated adult cells. An alkaline pHi supports various mechanisms involved in cellular proliferation and limits apoptosis, therefore promoting cell survival. We proposed that these early changes in pH take place before a MR-detectable recurrence occurs. To prove our hypothesis, we employed in-vivo 31P MR spectroscopic imaging (MRSI) in patients with recurrent glioblastoma (rGBM) before and under antiangiogenetic therapy (bevacizumab, BEV) until tumor progression.