title: Comparison of dosimetry between PET/CT and PET alone using (11)C-ITMM.
abstract: We used a new tracer, N-[4-[6-(isopropylamino) pyrimidin-4-yl]-1,3-thiazol-2-yl]-4-(11)C-methoxy-N-methylbenzamide ((11)C-ITMM), to compare radiation doses from positron emission tomography (PET)/computed tomography (CT) with previously published doses from PET alone. Twelve healthy volunteers [six males (mean age ± SD, 27.7 ± 6.7 years) and six females (31.8 ± 14.5 years)] in 12 examinations were recruited. Dose estimations from PET/CT were compared with those from PET alone. Regions of interest (ROIs) in PET/CT were delineated on the basis of low-dose CT (LD-CT) images acquired during PET/CT. Internal and external radiation doses were estimated using OLINDA/EXM 1.0 and CT-Expo software. The effective dose (ED) for (11)C-ITMM calculated from PET/CT was estimated to be 4.7 ± 0.5 μSv/MBq for the male subjects and 4.1 ± 0.7 μSv/MBq for the female subjects. The mean ED for (11)C-ITMM calculated from PET alone in a previous report was estimated to be 4.6 ± 0.3 μSv/MBq (males, n = 3). The ED values for (11)C-ITMM calculated from PET/CT in the male subjects were almost identical to those from PET alone. The absorbed doses (ADs) of the gallbladder, stomach, red bone marrow, and spleen calculated from PET/CT were significantly different from those calculated from PET alone. The EDs of (11)C-ITMM calculated from PET/CT were almost identical to those calculated from PET alone. The ADs in several organs calculated from PET/CT differed from those from PET alone. LD-CT images acquired during PET/CT may facilitate organ identification.
authors.affiliation: Department of Diagnostic Radiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan. itoukimiteru@yahoo.co.jp.|Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan. itoukimiteru@yahoo.co.jp.
authors.forename: Kimiteru
authors.initials: K
authors.lastname: Ito
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Muneyuki
authors.initials: M
authors.lastname: Sakata
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.|Department of Radiological Technology, Faculty of Health Sciences, Hokkaido University of Science, Sapporo, Hokkaido, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Oda
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Wagatsuma
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Toyohara
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ishibashi
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ishii
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Kiichi
authors.initials: K
authors.lastname: Ishiwata
mesh_terms: D000328:Adult; D001549:Benzamides / Q000737:chemistry*; D002250:Carbon Radioisotopes; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D011874:Radiometry / Q000379:methods*; D013844:Thiazoles / Q000737:chemistry*; D013997:Time Factors; D014018:Tissue Distribution; D051598:Whole Body Imaging; D055815:Young Adult
chemical_list: D001549:Benzamides; D002250:Carbon Radioisotopes; C573292:N-(4-(6-(isopropylamino)pyrimidin-4-yl)-1,3-thiazol-2-yl)-4-methoxy-N-methylbenzamide; D013844:Thiazoles
keywords: 11C-ITMM; Biodistribution; PET; PET/CT; Radiation dosimetry