Ellen Ackerstaff1, Makiko Suehiro1, Natalia Kruchevsky1, Sean Carlin1, Eric H. Rosenfeld1, Paul Burgman1, Guangbin Yang1, Geralda Torchon1, Ouathek Ouerfelli1, Pat B. Zanzonico1, Kristen L. Zakian1, Clifton C. Ling1, Jason A. Koutcher1
Tumor hypoxia is related to treatment response and outcome. We evaluated the ability of trifluoromisonidazole (TFmiso) to detect hypoxia in vivo and in vitro. In vivo, TFmiso could reproducibly measure whole-tumor hypoxia and the effect of oxygenation changes (carbogen, oxygen breathing) on tumor hypoxia. Its accumulation in hypoxic tumor areas was validated ex vivo using 18F-TFmiso autoradiography and pimonidazole immunohistochemistry. In vitro, 18F-TFmiso is taken up preferentially at [O2]<1% with the highest uptake in anoxic tumor cells and <50% of cellular TFmiso is protein bound. TFmiso imaging may be useful in identifying tumors that can be successfully reoxygenated and radiosensitized.