title: Target volume delineation for preoperative radiotherapy of rectal cancer: inter-observer variability and potential impact of FDG-PET/CT imaging.
abstract: To analyze the inter-observer variability and the potential impact of (18)F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) imaging for target volume delineation in preoperative radiotherapy of rectal cancer. Gross tumor volume (GTV) and clinical target volume (CTV) in 2 cases of rectal cancer were contoured by 10 radiation oncologists, 5 on CT and 5 on PET/CT images. Resulting volumes were analyzed by coefficient of variation (CV) and concordance index (CI). Mean GTV was 120 cc +/- 20.4 cc in case A and 119 cc +/- 35.7 cc in case B. Mean CTV was 723 cc +/- 147.5 cc in case A and 739 cc +/- 195.6 cc in case B. CV was lower and CI was similar or higher across the observers contouring GTV on PET/CT. CTV variability was less influenced by the use of PET/CT. PET/CT may allow reducing inter-observer variability in GTV delineation.
authors.affiliation: Radiotherapy, University Hospital Maggiore della Carita, via Solaroli 17, 28100 Novara, Italy. krengli@med.unipmn.it
authors.forename: Marco
authors.initials: M
authors.lastname: Krengli
authors.forename: Barbara
authors.initials: B
authors.lastname: Cannillo
authors.forename: Lucia
authors.initials: L
authors.lastname: Turri
authors.forename: Paolo
authors.initials: P
authors.lastname: Bagnasacco
authors.forename: Laura
authors.initials: L
authors.lastname: Berretta
authors.forename: Teresa
authors.initials: T
authors.lastname: Ferrara
authors.forename: Mario
authors.initials: M
authors.lastname: Galliano
authors.forename: Sergio
authors.initials: S
authors.lastname: Gribaudo
authors.forename: Antonella
authors.initials: A
authors.lastname: Melano
authors.forename: Fernando
authors.initials: F
authors.lastname: Munoz
authors.forename: Piera
authors.initials: P
authors.lastname: Sciacero
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Tseroni
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Bassi
authors.forename: Marco
authors.initials: M
authors.lastname: Brambilla
authors.forename: Eugenio
authors.initials: E
authors.lastname: Inglese
mesh_terms: D019788:Fluorodeoxyglucose F18; D006801:Humans; D015588:Observer Variation; D049268:Positron-Emission Tomography; D011300:Preoperative Care; D011379:Prognosis; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18