From the University of Washington, Seattle, Washington
Authors’ disclosures of potential conflicts of interest are found at the end of this article.
Address reprint requests to Kenneth A. Krohn, PhD, University of Washington, 1959 NE Pacific St., Rm. NW041 UWMC, Box 356004, Seattle, WA 98195-6004; e-mail: kkrohn{at}u.washington.edu
Overview: Hypoxia, an inadequate supply of oxygen, contributes to resistance to treatment. Its consequences are mediated by a series of hypoxia-initiated genomic changes activating glycolysis, angiogenesis, and other processes that result in overall diminished therapeutic response, malignant progression, increased probability of recurrence, locoregional spread, and distant metastases. Strategies are being developed to surmount the cure-limiting consequences of hypoxia, but methods are needed to select patients most likely to benefit from these new treatments. Although hypoxia is a common tumor phenotype, it is by no means universal, and it is often heterogeneous within an individual patient, suggesting that a three-dimensional image of hypoxia as provided by positron emission tomography should be clinically relevant. This review considers the biology of hypoxia, its consequences with respect to treatment, methods for imaging regional oxygenation in tissues, and how information regarding the oxygenation of tumors might result in improved treatment outcomes.
