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Updated: Aug 24, 2026
Tumor Hypoxia Assessment: In Vivo 3D Oxygen Imaging Through Electron Paramagnetic Resonance
Published on: February 14, 2025
Synergistic effects of hyperoxic gas breathing and reduced oxygen consumption on tumor oxygenation: a theoretical
Timothy W Secomb1, Richard Hsu, Mark W Dewhirst
1Department of Physiology, University of Arizona, Tucson, AZ 85724-5051, USA. secomb@u.arizona.edu
Purpose:
To simulate effects of reduced oxygen consumption combined with hyperoxic gas breathing on tumor oxygenation, and to test for synergistic effects.
Methods And Materials:
Diffusive oxygen transport was simulated for a small region of tumor containing a three-dimensional network of microvessels whose geometry was derived from in vivo observations. Changes in tissue partial pressure of oxygen (PO(2)) and hypoxic fraction (PO(2) < 5 mm Hg) resulting from a 30% reduction in oxygen consumption rate or breathing 100% oxygen were estimated. The synergistic effect was defined as the change in PO(2) with the two treatments combined, minus the sum of the changes with the separate treatments.
Results:
Predicted hypoxic fractions were 37% in the control state, 11% with reduced consumption, 23% with oxygen breathing alone, and 0% with the combined treatment. The synergistic effect was about 4 mm Hg at tissue points with very low initial PO(2) levels and decreased as initial PO(2) increased.
Conclusions:
Reduction of oxygen consumption via the Crabtree effect, by administration of glucose, has been proposed as a means to improve tumor oxygenation during radiation treatment. The results support previous experimental studies showing that this approach is more effective when combined with breathing of hyperoxic gases.
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