title: An innovative tool for intraoperative electron beam radiotherapy simulation and planning: description and initial evaluation by radiation oncologists.
abstract: OBJECTIVE
  Intraoperative electron beam radiation therapy (IOERT) involves a modified strategy of conventional radiation therapy and surgery. The lack of specific planning tools limits the spread of this technique. The purpose of the present study is to describe a new simulation and planning tool and its initial evaluation by clinical users.
  
  
  METHODS
  The tool works on a preoperative computed tomography scan. A physician contours regions to be treated and protected and simulates applicator positioning, calculating isodoses and the corresponding dose--volume histograms depending on the selected electron energy. Three radiation oncologists evaluated data from 15 IOERT patients, including different tumor locations. Segmentation masks, applicator positions, and treatment parameters were compared.
  
  
  RESULTS
  High parameter agreement was found in the following cases: three breast and three rectal cancer, retroperitoneal sarcoma, and rectal and ovary monotopic recurrences. All radiation oncologists performed similar segmentations of tumors and high-risk areas. The average applicator position difference was 1.2 ± 0.95 cm. The remaining cancer sites showed higher deviations because of differences in the criteria for segmenting high-risk areas (one rectal, one pancreas) and different surgical access simulated (two rectal, one Ewing sarcoma).
  
  
  CONCLUSIONS
  The results show that this new tool can be used to simulate IOERT cases involving different anatomic locations, and that preplanning has to be carried out with specialized surgical input.
authors.affiliation: Unidad de Medicina y Cirugía Experimental, Hospital General Universitario Gregorio Marañón, Madrid, Spain. jpascau@mce.hggm.es
authors.forename: Javier
authors.initials: J
authors.lastname: Pascau
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Santos Miranda
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Calvo
authors.forename: Ana
authors.initials: A
authors.lastname: Bouché
authors.forename: Virgina
authors.initials: V
authors.lastname: Morillo
authors.forename: Carmen
authors.initials: C
authors.lastname: González-San Segundo
authors.forename: Carlos
authors.initials: C
authors.lastname: Ferrer
authors.forename: Juan
authors.initials: J
authors.lastname: López Tarjuelo
authors.forename: Manuel
authors.initials: M
authors.lastname: Desco
mesh_terms: D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D004583:Electrons / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000532:radiotherapy; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D058958:Organs at Risk / Q000000981:diagnostic imaging; D010051:Ovarian Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D018787:Radiation Oncology; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D012186:Retroperitoneal Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D012509:Sarcoma / Q000000981:diagnostic imaging / Q000532:radiotherapy; D012512:Sarcoma, Ewing / Q000000981:diagnostic imaging / Q000532:radiotherapy; D014057:Tomography, X-Ray Computed / Q000379:methods