title: Patterns of extension of gastrointestinal stromal tumors (GIST) treated with imatinib (Gleevec®) by 18F-FDG PET/CT.
abstract: OBJECTIVE
  currently it is recognized the usefulness of 18F-FDG PET in assessing response to therapy with imatinib (Gleevec®) in the gastrointestinal tract sarcomas (GIST). To facilitate the follow-up of these studies is important to know the patterns of metastatic spread. The aim of this paper is to describe patterns observed in the 18F-FDG PET/CT.
  
  
  METHODS
  retrospective study included 29 patients who underwent 18F-FDG PET/CT after being diagnosed with unresectable or metastatic GIST. In total, 87 PET/CT studies were performed (1-6 controls per patient) with a mean time of follow-up 6-36 months. We analyzed the location of the lesions evidenced in PET, CT and fusion. Images were evaluated visually and semiquantitatively (SUV). In cases in which has been considered necessary, additional images have been undertaken: PET delayed imaging, intravenous contrast CT and inspiratory chest CT.
  
  
  RESULTS
  the most common primary site was the stomach (41%), small bowel (35%), and rectum (24%). Significant changes in the location of metastatic disease between pre-treatment and the monitoring were observed, with the appearance of more extra-abdominal disease.
  
  
  CONCLUSIONS
  individualization of protocol studies and interpretation of PET, CT and fused images were required for evaluation of treatment response to imatinib. Hybrid 18F-FDG PET/CT provides an accurate determination of the extent of GIST. While the most common metastatic site is the liver and peritoneum, in the following cases are common extra-abdominal disease.
authors: Unit of PET/CT. CETIR Grupo Médico-ERESA, Esplugues de Llobregat, C/ Josep Anselm Clavé 100, Barcelona, Spain. evalls@cetir.es
authors: Eulalia
authors: E
authors: Valls-Ferrusola
authors: J R
authors: JR
authors: García-Garzón
authors: Ana
authors: A
authors: Ponce-López
authors: Marina
authors: M
authors: Soler-Peter
authors: Silvia
authors: S
authors: Fuertes-Cabero
authors: Merce
authors: M
authors: Moragas-Solanes
authors: Eduard
authors: E
authors: Riera-Gil
authors: Ignasi
authors: I
authors: Carrió-Gasset
authors: Francisco
authors: F
authors: Lomeña-Caballero
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001549:Benzamides; D016903:Drug Monitoring; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D046152:Gastrointestinal Stromal Tumors / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D000068877:Imatinib Mesylate; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009362:Neoplasm Metastasis; D010879:Piperazines / Q000627:therapeutic use*; D049268:Positron-Emission Tomography; D011743:Pyrimidines / Q000627:therapeutic use*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D000068877:Imatinib Mesylate