title: 4'-[Methyl-11C]-thiothymidine PET/CT for proliferation imaging in non-small cell lung cancer.
abstract: A new tracer, 4'-[methyl-(11)C]-thiothymidine ((11)C-4DST), has been developed as an in vivo cell proliferation marker based on the DNA incorporation method. This study evaluated the potential of (11)C-4DST PET/CT for imaging proliferation in non-small cell lung cancer (NSCLC), compared with (18)F-FDG PET/CT.
  
  
  METHODS
  Eighteen patients with lung lesions were examined by PET/CT using (11)C-4DST and (18)F-FDG. We constructed decay-corrected time-activity curves of 9 major regions as the mean standardized uptake value. We then compared the maximum standardized uptake value (SUVmax) of lung tumors on both (11)C-4DST and (18)F-FDG PET/CT with the Ki-67 index of cellular proliferation and with CD31-positive vessels as a marker of angiogenesis in surgical pathology.
  
  
  RESULTS
  NSCLC was pathologically confirmed in 19 lesions of 18 patients. Physiologic accumulation of (11)C-4DST was high in liver, kidney, and bone marrow and low in aorta, brain, lung, and myocardium. Biodistribution of (11)C-4DST was almost stable by 20 min after injection of (11)C-4DST. Mean (11)C-4DST SUVmax for lung cancer was 2.9 ± 1.0 (range, 1.5-4.7), significantly different from mean (18)F-FDG SUVmax, which was 6.2 ± 4.5 (range, 0.9-17.3; P < 0.001). The correlation coefficient between SUVmax and Ki-67 index was higher with (11)C-4DST (r = 0.82) than with (18)F-FDG (r = 0.71). The correlation coefficient between SUVmax and CD31 was low with both (11)C-4DST (r = 0.21) and (18)F-FDG (r = 0.21), showing no significant difference between the tracers.
  
  
  CONCLUSIONS
  A higher correlation with proliferation of lung tumors was seen for (11)C-4DST than for (18)F-FDG. (11)C-4DST PET/CT may allow noninvasive imaging of DNA synthesis in NSCLC.
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, National Center for Global Health and Medicine, Tokyo, Japan. ryogominamimoto@yahoo.co.jp
authors.forename: Ryogo
authors.initials: R
authors.lastname: Minamimoto
authors.forename: Jun
authors.initials: J
authors.lastname: Toyohara
authors.forename: Ayako
authors.initials: A
authors.lastname: Seike
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ito
authors.forename: Hisako
authors.initials: H
authors.lastname: Endo
authors.forename: Miyako
authors.initials: M
authors.lastname: Morooka
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakajima
authors.forename: Takuya
authors.initials: T
authors.lastname: Mitsumoto
authors.forename: Kimiteru
authors.initials: K
authors.lastname: Ito
authors.forename: Momoko
authors.initials: M
authors.lastname: Okasaki
authors.forename: Kiichi
authors.initials: K
authors.lastname: Ishiwata
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kubota
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D002250:Carbon Radioisotopes; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008168:Lung / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D049268:Positron-Emission Tomography; D013936:Thymidine / Q000031:analogs & derivatives* / Q000378:metabolism; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging
chemical_list: D002250:Carbon Radioisotopes; D019394:Ki-67 Antigen; D019408:Platelet Endothelial Cell Adhesion Molecule-1; C024529:5-((methylthio)methyl)-2'-deoxyuridine; D013936:Thymidine