title: Efficacy of PET-CT for predicting the malignant potential of gastrointestinal stromal tumors.
abstract: OBJECTIVE
  Gastrointestinal stromal tumor (GIST) is the most common sarcoma of the intestinal tract. The risk category is usually determined by tumor size and mitotic count, but accurate preoperative diagnosis of GIST is very difficult. The purpose of this study is to evaluate the efficacy of positron emission tomography (PET)-CT for predicting the malignant potential of gastrointestinal stromal tumors.
  
  
  METHODS
  Ten patients with GIST who underwent a preoperative PET-CT examination were divided into two groups by risk category, and various factors were compared between the two groups. The relationships between the maximum standardized uptake value (SUVmax) and GIST parameters were examined.
  
  
  RESULTS
  Patients were classified into two groups by their risk category: (low/intermediate-risk or high-risk). The SUVmax was significantly higher in the high-risk group (11.0 ± 3.04) than in the low/intermediate-risk group (2.1 ± 1.5). The Ki67 labeling index was also significantly higher in the high-risk group (8.63 ± 6.2) than in the low/intermediate-risk group (1.75 ± 0.52). There was a significant correlation between the Ki67 labeling index and the SUVmax (p = 0.028) and between the mitotic index and the SUVmax (p = 0.029).
  
  
  CONCLUSIONS
  PET-CT can predict malignant potential. Cases with a SUVmax of over 5 may have malignant potential.
authors.affiliation: The Department of Surgery, The University of Tokushima, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Kozo
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Shimada
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Kurita
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Sato
authors.forename: Takashi
authors.initials: T
authors.lastname: Iwata
authors.forename: Shinya
authors.initials: S
authors.lastname: Morimoto
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Miyatani
authors.forename: Hideya
authors.initials: H
authors.lastname: Kashihara
authors.forename: Chie
authors.initials: C
authors.lastname: Takasu
authors.forename: Noriko
authors.initials: N
authors.lastname: Matsumoto
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D046152:Gastrointestinal Stromal Tumors / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012306:Risk; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18