Computer Simulation of Specificity for \textit{In Vivo} Breast Cancer Diagnosis by Carbogen-Enhanced Differential `Femton' Oximetry (`DFO')

We performed computer simulation study of noninvasive diagnosis by DFO of hypoxia in a 1 cm tumor in 10 cm breast. Unlike \textit{in vitro} cases (previous Abstract), background $\gamma $'s from non hypoxic tissue will mask tumor $\gamma $ signal, thus true hypoxia Q = -0.9 will be observed as apparent Q' = - 0.1. We propose to amplify Q' by replacing air breathing with carbogen (O$_{2}$ 95{\%}, CO$_{2}$ 5{\%}) thus making use of vasco-constrictive property that carbogen breathing increases O in normal tissue 3-fold, while O in subcutaneous hypoxic tumors remains const. This enhances apparent Q' to -0.25, shown to be detectable by DFO with specificity 99{\%}. Principle of Femto Onco Diagnostics with and w/o carbogen, will be tested on R3230 tumors in Fischer rats at UCI Center for Functional Onco Imaging. Our probe (`OncoSensor') requires imager guidance, except for palpable tumors.