Kentaro Kobayashi1, Osamu Manabe1, Kenji Hirata2, Shigeru Yamaguchi3, Hiroyuki Kobayashi4, Shunsuke Terasaka4, Takuya Toyonaga5, Sho Furuya1, Keiichi Magota6, Yuji Kuge7, Kohsuke Kudo8,9, Tohru Shiga1, Nagara Tamaki10. 1. Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Hokkaido, 060-8638, Japan. 2. Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Hokkaido, 060-8638, Japan. khirata@med.hokudai.ac.jp. 3. Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan. 4. Kashiwaba Neurosurgery Hospital, Sapporo, Japan. 5. Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA. 6. Division of Medical Imaging and Technology, Hokkaido University Hospital, Sapporo, Japan. 7. Central Institute of Isotope Science, Hokkaido University, Sapporo, Japan. 8. Department of Diagnostic Imaging, Hokkaido University Graduate School of Medicine, Sapporo, Japan. 9. Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan. 10. Department of Radiology, Kyoto Prefectural University, Kyoto, Japan.
Abstract
PURPOSE: 18F-fluoromisonidazole (18F-FMISO) is the most widely used positron emission tomography (PET) tracer for imaging tumor hypoxia. Previous reports suggested that the time from injection to the scan may affect the assessment of 18F-FMISO uptake. Herein, we directly compared the images at 2 h and 4 h after a single injection of 18F-FMISO. METHODS: Twenty-three patients with or suspected of having a brain tumor were scanned twice at 2 and 4 h following an intravenous injection of 18F-FMISO. We estimated the mean standardized uptake value (SUV) of the gray matter and white matter and the gray-to-white matter ratio in the background brain tissue from the two scans. We also performed a semi-quantitative analysis using the SUVmax and maximum tumor-to-normal ratio (TNR) for the tumor. RESULTS: At 2 h, the SUVmean of gray matter was significantly higher than that of white matter (median 1.23, interquartile range (IQR) 1.10-1.32 vs. 1.04, IQR 0.95-1.16, p < 0.0001), whereas at 4 h, it significantly decreased to approach that of the white matter (1.10, IQR 1.00-1.23 vs. 1.02, IQR 0.93-1.13, p = NS). The gray-to-white matter ratio thus significantly declined from 1.17 (IQR 1.14-1.19) to 1.09 (IQR 1.07-1.10) (p < 0.0001). All 7 patients with glioblastoma showed significant increases in the SUVmax (2.20, IQR 1.67-3.32 at 2 h vs. 2.65, IQR 1.74-4.41 at 4 h, p = 0.016) and the TNR (1.75, IQR 1.40-2.38 at 2 h vs. 2.34, IQR 1.67-3.60 at 4 h, p = 0.016). CONCLUSION: In the assessment of hypoxic tumors, 18F-FMISO PET for hypoxia imaging should be obtained at 4 h rather than 2 h after the injection.
PURPOSE:18F-fluoromisonidazole (18F-FMISO) is the most widely used positron emission tomography (PET) tracer for imaging tumor hypoxia. Previous reports suggested that the time from injection to the scan may affect the assessment of 18F-FMISO uptake. Herein, we directly compared the images at 2 h and 4 h after a single injection of 18F-FMISO. METHODS: Twenty-three patients with or suspected of having a brain tumor were scanned twice at 2 and 4 h following an intravenous injection of 18F-FMISO. We estimated the mean standardized uptake value (SUV) of the gray matter and white matter and the gray-to-white matter ratio in the background brain tissue from the two scans. We also performed a semi-quantitative analysis using the SUVmax and maximum tumor-to-normal ratio (TNR) for the tumor. RESULTS: At 2 h, the SUVmean of gray matter was significantly higher than that of white matter (median 1.23, interquartile range (IQR) 1.10-1.32 vs. 1.04, IQR 0.95-1.16, p < 0.0001), whereas at 4 h, it significantly decreased to approach that of the white matter (1.10, IQR 1.00-1.23 vs. 1.02, IQR 0.93-1.13, p = NS). The gray-to-white matter ratio thus significantly declined from 1.17 (IQR 1.14-1.19) to 1.09 (IQR 1.07-1.10) (p < 0.0001). All 7 patients with glioblastoma showed significant increases in the SUVmax (2.20, IQR 1.67-3.32 at 2 h vs. 2.65, IQR 1.74-4.41 at 4 h, p = 0.016) and the TNR (1.75, IQR 1.40-2.38 at 2 h vs. 2.34, IQR 1.67-3.60 at 4 h, p = 0.016). CONCLUSION: In the assessment of hypoxic tumors, 18F-FMISO PET for hypoxia imaging should be obtained at 4 h rather than 2 h after the injection.
Entities:
Keywords:
Fluoromisonidazole; Glioblastoma; Hypoxia; Positron emission tomography; Scan timing; This article is part of the Topical Collection on Oncology – Brain
Authors: Shiliang Huang; Joel E Michalek; David A Reardon; Patrick Y Wen; John R Floyd; Peter T Fox; Geoffrey D Clarke; Paul A Jerabek; Kathleen M Schmainda; Mark Muzi; Hyewon Hyun; Eudocia Quant Lee; Andrew J Brenner Journal: Sci Rep Date: 2021-04-07 Impact factor: 4.379