title: Anatomical contouring variability in thoracic organs at risk.
abstract: The purpose of this study was to determine whether contouring thoracic organs at risk was consistent among medical dosimetrists and to identify how trends in dosimetrist׳s education and experience affected contouring accuracy. Qualitative and quantitative methods were used to contextualize the raw data that were obtained. A total of 3 different computed tomography (CT) data sets were provided to medical dosimetrists (N = 13) across 5 different institutions. The medical dosimetrists were directed to contour the lungs, heart, spinal cord, and esophagus. The medical dosimetrists were instructed to contour in line with their institutional standards and were allowed to use any contouring tool or technique that they would traditionally use. The contours from each medical dosimetrist were evaluated against "gold standard" contours drawn and validated by 2 radiation oncology physicians. The dosimetrist-derived contours were evaluated against the gold standard using both a Dice coefficient method and a penalty-based metric scoring system. A short survey was also completed by each medical dosimetrist to evaluate their individual contouring experience. There was no significant variation in the contouring consistency of the lungs and spinal cord. Intradosimetrist contouring was consistent for those who contoured the esophagus and heart correctly; however, medical dosimetrists with a poor metric score showed erratic and inconsistent methods of contouring.
authors.affiliation: Medical Dosimetry Program, University of Wisconsin, La Crosse, WI. Electronic address: rmccall86@gmail.com.
authors.forename: Ross
authors.initials: R
authors.lastname: McCall
authors.affiliation: Medical Dosimetry Program, University of Wisconsin, La Crosse, WI.
authors.forename: Grayden
authors.initials: G
authors.lastname: MacLennan
authors.affiliation: Medical Dosimetry Program, University of Wisconsin, La Crosse, WI.
authors.forename: Matthew
authors.initials: M
authors.lastname: Taylor
authors.affiliation: Medical Dosimetry Program, University of Wisconsin, La Crosse, WI.
authors.forename: Nishele
authors.initials: N
authors.lastname: Lenards
authors.affiliation: Canis Lupus LLC, Madison, WI.
authors.forename: Benjamin E
authors.initials: BE
authors.lastname: Nelms
authors.affiliation: Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL.
authors.forename: Matthew
authors.initials: M
authors.lastname: Koshy
authors.affiliation: Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Lemons
authors.affiliation: Medical Dosimetry Program, University of Wisconsin, La Crosse, WI.
authors.forename: Ashley
authors.initials: A
authors.lastname: Hunzeker
mesh_terms: D004947:Esophagus / Q000528:radiation effects; D006321:Heart / Q000528:radiation effects; D006801:Humans; D008168:Lung / Q000528:radiation effects; D058958:Organs at Risk; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D013116:Spinal Cord / Q000528:radiation effects
keywords: Contour variability; Contouring; Esophagus; Heart; Organs at risk; Spine; Thorax