THE APPARENT DIFFUSION CONSTANT MEASURED BY MRI CORRELATES WITH PO(2) IN A RIF-1 TUMOR

As tissue oxygen tension (pO(2)) is an important variable in cancer therapy, it would be of major clinical benefit to be able to measure pO(2) noninvasively. Current methods for determining pO(2) in clinical settings are limited to superficial tumors. The authors measured the apparent diffusion constant (ADC) in an implanted murine fibrosarcoma (RIF-1) using magnetic resonance imaging and correlated the ADC with tissue pO(2) measured by electron paramagnetic resonance oximetry, The ADC correlates significantly with tissue pO, in this tumor (r = 0.89; n = 14) and so may provide a noninvasive index of pO(2) in tumors.