title: Assessment of intraoperative 3D imaging alternatives for IOERT dose estimation.
abstract: Intraoperative electron radiation therapy (IOERT) involves irradiation of an unresected tumour or a post-resection tumour bed. The dose distribution is calculated from a preoperative computed tomography (CT) study acquired using a CT simulator. However, differences between the actual IOERT field and that calculated from the preoperative study arise as a result of patient position, surgical access, tumour resection and the IOERT set-up. Intraoperative CT imaging may then enable a more accurate estimation of dose distribution. In this study, we evaluated three kilovoltage (kV) CT scanners with the ability to acquire intraoperative images. Our findings indicate that current IOERT plans may be improved using data based on actual anatomical conditions during radiation. The systems studied were two portable systems ("O-arm", a cone-beam CT [CBCT] system, and "BodyTom", a multislice CT [MSCT] system) and one CBCT integrated in a conventional linear accelerator (LINAC) ("TrueBeam"). TrueBeam and BodyTom showed good results, as the gamma pass rates of their dose distributions compared to the gold standard (dose distributions calculated from images acquired with a CT simulator) were above 97% in most cases. The O-arm yielded a lower percentage of voxels fulfilling gamma criteria owing to its reduced field of view (which left it prone to truncation artefacts). Our results show that the images acquired using a portable CT or even a LINAC with on-board kV CBCT could be used to estimate the dose of IOERT and improve the possibility to evaluate and register the treatment administered to the patient.
authors: Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain. Electronic address: vgarcia@mce.hggm.es.
authors: Verónica
authors: V
authors: García-Vázquez
authors: Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain.
authors: Eugenio
authors: E
authors: Marinetto
authors: Departamento de Ingeniería Electrónica, ETSI Telecomunicación, Universidad Politécnica de Madrid, Madrid, Spain; Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain.
authors: Pedro
authors: P
authors: Guerra
authors: GMV SA, Madrid, Spain.
authors: Manlio Fabio
authors: MF
authors: Valdivieso-Casique
authors: Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Departamento de Oncología, Hospital General Universitario Gregorio Marañón, Madrid, Spain; Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain.
authors: Felipe Ángel
authors: FÁ
authors: Calvo
authors: Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Servicio de Oncología Radioterápica, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors: Eduardo
authors: E
authors: Alvarado-Vásquez
authors: Service of Radiation Oncology, Instituto de Radiomedicina, Santiago, Chile; Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain.
authors: Claudio Vicente
authors: CV
authors: Sole
authors: Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, USA.
authors: Kirby Gannett
authors: KG
authors: Vosburgh
authors: Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Spain; Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain.
authors: Manuel
authors: M
authors: Desco
authors: Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Spain; Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain.
authors: Javier
authors: J
authors: Pascau
mesh_terms: D054893:Cone-Beam Computed Tomography / Q000295:instrumentation / Q000379:methods; D004583:Electrons / Q000627:therapeutic use*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D007432:Intraoperative Period; D061330:Multidetector Computed Tomography / Q000295:instrumentation / Q000379:methods; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy* / Q000601:surgery; D011879:Radiotherapy Dosage; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
keywords: Dosisverteilung; IOERT; Intraoperative Bildgebung; Strahlentherapie; dose distribution; intraoperative imaging; radiotherapy