MKI67 and head and neck cancer: Thus, in this study, we simultaneously evaluated the dynamic changes in intratumoral hypoxic and proliferative states using FMISO and FLT, and further verified the results by immunohistochemical staining of pimonidazole and Ki-67 after a single dose of radiation of human head and neck cancer xenografts using a moderately radiosensitive cancer cell line, FaDu.