title: Tumor hypoxia: a new PET imaging biomarker in clinical oncology.
abstract: Tumor hypoxia is associated with tumor progression and resistance to various treatments. Noninvasive imaging using positron emission tomography (PET) and F-18-labeled fluoromisonidazole (FMISO) was recently introduced in order to define and quantify tumor hypoxia. The FMISO uptake was closely correlated with pimonidazole immunohistochemistry and hypoxia-inducible factor 1 expression in basic studies. Tumor hypoxia in head and neck cancers and other tumors in a clinical setting may also indicate resistance to radiation and/or chemotherapy. Hypoxic imaging may thus play a new and important role for suitable radiation planning, including dose escalation and dose reduction based on the image findings. Such radiation-dose painting based on the findings of hypoxia may require high-performance PET imaging to provide high target-to-background ratio images and an optimal quantitative parameter to define the hypoxic region. A multicenter prospective study using data from a large number of patients is also warranted to test the clinical value of hypoxic imaging.
authors.affiliation: Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, North 15th, West 7th, Kita-ku, Sapporo, 060-8638, Japan. natamaki@med.hokudai.ac.jp.
authors.forename: Nagara
authors.initials: N
authors.lastname: Tamaki
authors.affiliation: Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, North 15th, West 7th, Kita-ku, Sapporo, 060-8638, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirata
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000628:therapy; D006801:Humans; D051793:Hypoxia-Inducible Factor 1 / Q000378:metabolism; D008920:Misonidazole / Q000031:analogs & derivatives; D049268:Positron-Emission Tomography / Q000379:methods; D011836:Radiation Tolerance; D019275:Radiopharmaceuticals; D000072258:Tumor Hypoxia
chemical_list: D015415:Biomarkers; D051793:Hypoxia-Inducible Factor 1; D019275:Radiopharmaceuticals; C031843:fluoromisonidazole; D008920:Misonidazole
keywords: Hypoxia; Molecular imaging; PET; Radiosensitivity