Tumor hypoxia: long ignored but now detectable and potentially actionable

Summary Oxygen-enhanced MRI was successfully applied to 24 patients with human papillomavirus–associated oropharyngeal cancer. This prospective trial rigorously evaluated reproducibility and changes with respect to tumor radiation. Analyses compared hypoxic volumes and hypoxic fractions. It represents important progress in developing a practical approach to assessing tumor hypoxia in patients noninvasively. See related article by Dubec et al., p. XX