Therapeutic Vascular Targeting and Irradiation: Correlation of MRI and Tissue Changes at Cellular and Molecular Levels to Optimizing Outcome
Abstract
Vascular targeting agents (VTA) are new types of anticancer drugs that act on existing tumor vasculature, causing vascular disruption, which ultimately leads to extensive ischemic tumor cell death. One major goal of this project is to assess physiological changes at different time points following VTA in breast tumors. Continuous studies of tumor vascular perfusion and tissue oxygenation by MRI confirmed our previous findings during Year I. Complementary data during this annum showed that a significant drop in mean tumor pO2 within 90 min after administration of combretastatin A4 phosphate (CA4P) and a further decrease was observed at 2 h. Intriguingly, the initial changes in pO2 in central and peripheral regions were parallel, but by 24 h post treatment significant difference was apparent: pO2 in the periphery improved significantly, while the center remained hypoxic. These data are consistent with DCE (dynamic contrast enhanced) MRI, which revealed a ~70% decrease in perfusion/permeability at 2 h, which recovered fully after 24 h in a thin peripheral region, but not the tumor center. Based on the imaging results, the radiation treatment has been designed and initiated. We believe that quantitative pO2 measurements are potentially important for optimizing therapeutic combination of CA4P with irradiation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2005
- Accession Number
- ADA441290
Entities
People
- Dawn Zhao
Organizations
- University of Texas at Dallas