title: A prospective clinical trial of tumor hypoxia imaging with 18F-fluoromisonidazole positron emission tomography and computed tomography (F-MISO PET/CT) before and during radiation therapy.
abstract: To visualize intratumoral hypoxic areas and their reoxygenation before and during fractionated radiation therapy (RT), (18)F-fluoromisonidazole positron emission tomography and computed tomography (F-MISO PET/CT) were performed. A total of 10 patients, consisting of four with head and neck cancers, four with gastrointestinal cancers, one with lung cancer, and one with uterine cancer, were included. F-MISO PET/CT was performed twice, before RT and during fractionated RT of approximately 20 Gy/10 fractions, for eight of the 10 patients. F-MISO maximum standardized uptake values (SUVmax) of normal muscles and tumors were measured. The tumor-to-muscle (T/M) ratios of F-MISO SUVmax were also calculated. Mean SUVmax ± standard deviation (SD) of normal muscles was 1.25 ± 0.17, and SUVmax above the mean + 2 SD (≥1.60 SUV) was regarded as a hypoxic area. Nine of the 10 tumors had an F-MISO SUVmax of ≥1.60. All eight tumors examined twice showed a decrease in the SUVmax, T/M ratio, or percentage of hypoxic volume (F-MISO ≥1.60) at approximately 20 Gy, indicating reoxygenation. In conclusion, accumulation of F-MISO of ≥1.60 SUV was regarded as an intratumoral hypoxic area in our F-MISO PET/CT system. Most human tumors (90%) in this small series had hypoxic areas before RT, although hypoxic volume was minimal (0.0-0.3%) for four of the 10 tumors. In addition, reoxygenation was observed in most tumors at two weeks of fractionated RT.
authors.affiliation: Department of Radiation Oncology, Kinki University Faculty of Medicine, Osaka-Sayama, Japan.
authors.forename: Izumi
authors.initials: I
authors.lastname: Tachibana
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Toru
authors.initials: T
authors.lastname: Shibata
authors.forename: Shuichi
authors.initials: S
authors.lastname: Kanamori
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Nakamatsu
authors.forename: Ryuta
authors.initials: R
authors.lastname: Koike
authors.forename: Tatsuyuki
authors.initials: T
authors.lastname: Nishikawa
authors.forename: Kazuki
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Masaya
authors.initials: M
authors.lastname: Tamura
authors.forename: Makoto
authors.initials: M
authors.lastname: Hosono
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015687:Cell Hypoxia / Q000528:radiation effects; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008920:Misonidazole / Q000493:pharmacokinetics; D057054:Molecular Imaging / Q000379:methods*; D064847:Multimodal Imaging / Q000379:methods*; D009369:Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000532:radiotherapy*; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D008920:Misonidazole
keywords: 18F-misonidazole; PET/CT; reoxygenation; tumor hypoxia