Tumor pH and Vascularity in Human Prostate Cancer Models

Ellen Ackerstaff¹, Natalia Kruchevsky¹, Radka Stoyanova², Sean D. Carlin¹, Nerissa Viola-Villegas¹, Kuntalkumar Sevak¹, Jason S. Lewis¹, Jason A. Koutcher¹

Tumor hypoxia and pH have been related to tumor aggressiveness, treatment response, and outcome. Here, we evaluated tumoral pH, metabolism, and vascularity in human prostate cancer models using ¹H-decoupled ³¹P MR spectroscopy and dynamic contrast-enhanced MR imaging (DCE-MRI). Tumoral, extracellular pH (pHe) was measured using 3-aminopropylphosphonate (3-APP), while spatial heterogeneity of tumor hypoxia was evaluated from DCE-MRI data using a novel pattern recognition approach. In tumors without extensive necrosis, pHe appears to be only slightly acidic and tied to the extent of tumoral hypoxia, as determined from vascularity.