title: Impact of CT and 18F-deoxyglucose positron emission tomography image fusion for conformal radiotherapy in esophageal carcinoma.
abstract: OBJECTIVE
  To study the impact of fused (18)F-fluoro-deoxy-D-glucose (FDG)-hybrid positron emission tomography (PET) and computed tomography (CT) images on conformal radiotherapy planning for esophageal carcinoma patients.
  
  
  METHODS
  Thirty-four esophageal carcinoma patients were referred for concomitant radiotherapy and chemotherapy with radical intent. Each patient underwent CT and FDG-hybrid PET for simulation treatment in the same treatment position. PET images were coregistered using five fiducial markers. Target delineation was initially performed on CT images, and the corresponding PET data were subsequently used as an overlay to CT data to define the target volume.
  
  
  RESULTS
  (18)F-fluorodeoxy-D-glucose-PET identified previously undetected distant metastatic disease in 2 patients, making them ineligible for curative conformal radiotherapy. The gross tumor volume (GTV) was decreased by CT and FDG image fusion in 12 patients (35%) and increased in 7 patients (21%). The GTV reduction was > or =25% in 4 patients owing to a reduction in the length of the esophageal tumor. The GTV increase was > or =25% with FDG-PET in 2 patients owing to the detection of occult mediastinal lymph node involvement in 1 patient and an increased length of the esophageal tumor in 1 patient. Modifications of the GTV affected the planning treatment volume in 18 patients. Modifications of the delineation of the GTV and displacement of the isocenter of the planning treatment volume by FDG-PET also affected the percentage of total lung volume receiving >20 Gy in 25 patients (74%), with a dose reduction in 12 patients and dose increase in 13.
  
  
  CONCLUSIONS
  In our study, CT and FDG-PET image fusion appeared to have an impact on treatment planning and management of esophageal carcinoma. The affect on treatment outcome remains to be demonstrated.
authors.affiliation: Department of Radiation Oncology, Tenon Hospital A.P.-H.P., 4 rue de la Chine, Paris 75970, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Moureau-Zabotto
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Touboul
authors.forename: Delphine
authors.initials: D
authors.lastname: Lerouge
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Deniaud-Alexandre
authors.forename: Dany
authors.initials: D
authors.lastname: Grahek
authors.forename: Jean-Noël
authors.initials: JN
authors.lastname: Foulquier
authors.forename: Yolande
authors.initials: Y
authors.lastname: Petegnief
authors.forename: Benoît
authors.initials: B
authors.lastname: Grès
authors.forename: Hanna
authors.initials: H
authors.lastname: El Balaa
authors.forename: Kaldoun
authors.initials: K
authors.lastname: Kerrou
authors.forename: Françoise
authors.initials: F
authors.lastname: Montravers
authors.forename: Katia
authors.initials: K
authors.lastname: Keraudy
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Tiret
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Gendre
authors.forename: Jean-Didier
authors.initials: JD
authors.lastname: Grange
authors.forename: Sidney
authors.initials: S
authors.lastname: Houry
authors.forename: Jean-Noël
authors.initials: JN
authors.lastname: Talbot
mesh_terms: D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D020266:Radiotherapy, Conformal / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18