title: Impact of 18-fluorodeoxyglucose positron emission tomography on computed tomography defined target volumes in radiation treatment planning of esophageal cancer: reduction in geographic misses with equal inter-observer variability: PET/CT improves esophageal target definition.
abstract: Target volume definition in modern radiotherapy is based on planning computed tomography (CT). So far, 18-fluorodeoxyglucose positron emission tomography (FDG-PET) has not been included in planning modality in volume definition of esophageal cancer. This study evaluates fusion of FDG-PET and CT in patients with esophageal cancer in terms of geographic misses and inter-observer variability in volume definition. In 28 esophageal cancer patients, gross, clinical and planning tumor volumes (GTV; CTV; PTV) were defined on planning CT by three radiation oncologists. After software-based emission tomography and computed tomography (PET/CT) fusion, tumor delineations were redefined by the same radiation-oncologists. Concordance indexes (CCI's) for CT and PET/CT based GTV, CTV and PTV were calculated for each pair of observers. Incorporation of PET/CT modified tumor delineation in 17/28 subjects (61%) in cranial and/or caudal direction. Mean concordance indexes for CT-based CTV and PTV were 72 (55-86)% and 77 (61-88)%, respectively, vs. 72 (47-99)% and 76 (54-87)% for PET/CT-based CTV and PTV. Paired analyses showed no significant difference in CCI between CT and PET/CT. Combining FDG-PET and CT may improve target volume definition with less geographic misses, but without significant effects on inter-observer variability in esophageal cancer.
authors.affiliation: Department of Surgical Oncology, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: L M A
authors.initials: LM
authors.lastname: Schreurs
authors.forename: D M
authors.initials: DM
authors.lastname: Busz
authors.forename: G M R M
authors.initials: GM
authors.lastname: Paardekooper
authors.forename: J C
authors.initials: JC
authors.lastname: Beukema
authors.forename: P L
authors.initials: PL
authors.lastname: Jager
authors.forename: E J
authors.initials: EJ
authors.lastname: Van der Jagt
authors.forename: G M
authors.initials: GM
authors.lastname: van Dam
authors.forename: H
authors.initials: H
authors.lastname: Groen
authors.forename: J Th M
authors.initials: JT
authors.lastname: Plukker
authors.forename: J A
authors.initials: JA
authors.lastname: Langendijk
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D049268:Positron-Emission Tomography / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18