title: Can positron emission tomography detect colorectal adenomas and cancers?
abstract: OBJECTIVE
  Fluorine-18 2-fluoro-2-deoxy-d-glucose positron emission tomography (PET) is effective and less invasive than other modalities used to diagnose tumors, including colorectal cancer (CRC). However, the detectability of adenomas and CRCs, especially in the early stages, is unclear.
  
  
  METHODS
  We evaluated the records of 2323 consecutive eligible patients who underwent both a total colonoscopy (TCS) and PET between October 2002 and September 2012 at a tertiary cancer center. The PET findings were verified by TCS performed independently within 1 year. Target lesions were defined as CRCs and adenomas that were 6 mm or larger in size.
  
  
  RESULTS
  Total colonoscopy detected 532 target lesions ≥ 6 mm in size: 56 T2-T4 CRCs, 39 T1 CRCs, 223 advanced adenomas, and 214 low-grade adenomas. Of the 532 lesions, 216 (40.6%) were PET positive. Of the 369 cases with positive uptakes, PET detected target lesions in the matched segments for 58.5% (216/369). Sensitivity of PET to T2-T4 CRCs, T1 CRCs, advanced adenomas, and low-grade adenomas was 92.9%, 79.5%, 50.7%, and 9.3%, respectively. PET could detect 76.5% (13/17) of T1 CRCs whose size is 10 to 19 mm and 85.0% (17/20) of T1 CRCs equal or larger than 20 mm. The multivariate analysis excluding T2-T4 CRCs showed malignant histology, larger size, protruded lesions, villous histology, and lesions in distal colon were significant factors.
  
  
  CONCLUSIONS
  Sensitivity of PET for detecting T2-T4 and even T1 cancers are promising. However, sensitivity of PET to adenomas, even advanced adenomas, is limited.
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Igarashi
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Kinichi
authors.initials: K
authors.lastname: Hotta
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Imai
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Sayo
authors.initials: S
authors.lastname: Ito
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Kawata
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Kakushima
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Takizawa
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsubayashi
authors.affiliation: Diagnostic imaging, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Endo
authors.affiliation: Diagnostic imaging, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Kouiku
authors.initials: K
authors.lastname: Asakura
authors.affiliation: Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Oishi
authors.affiliation: Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Tadakazu
authors.initials: T
authors.lastname: Shimoda
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ono
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: colonoscopy; colorectal adenoma; colorectal cancer; diagnostic imaging