title: A Model for Precise and Uniform Pelvic- and Limb-Sparing Abdominal Irradiation to Study the Radiation-Induced Gastrointestinal Syndrome in Mice Using Small Animal Irradiation Systems.
abstract: OBJECTIVE
  Currently, no readily available mitigators exist for acute abdominal radiation injury. Here, we present an animal model for precise and homogenous limb-sparing abdominal irradiation (LSAIR) to study the radiation-induced gastrointestinal syndrome (RIGS).
  
  
  METHODS
  The LSAIR technique was developed using the small animal radiation research platform (SARRP) with image guidance capabilities. We delivered LSAIR at doses between 14 and 18 Gy on 8- to 10-week-old male C57BL/6 mice. Histological analysis was performed to confirm that the observed mortality was due to acute abdominal radiation injury.
  
  
  RESULTS
  A steep dose-response relationship was found for survival, with no deaths seen at doses below 16 Gy and 100% mortality at above 17 Gy. All deaths occurred between 6 and 10 days after irradiation, consistent with the onset of RIGS. This was further confirmed by histological analysis showing clear differences in the number of regenerative intestinal crypts between animals receiving sublethal (14 Gy) and 100% lethal (18 Gy) radiation.
  
  
  CONCLUSIONS
  The developed LSAIR technique provides uniform dose delivery with a clear dose response, consistent with acute abdominal radiation injury on histological examination. This model can provide a useful tool for researchers investigating the development of mitigators for accidental or clinical high-dose abdominal irradiation.
authors.affiliation: Department of Radiation Oncology, Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY, USA.
authors.forename: N Patrik
authors.initials: NP
authors.lastname: Brodin
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Velcich
authors.affiliation: Department of Radiation Oncology, Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY, USA.
authors.forename: Chandan
authors.initials: C
authors.lastname: Guha
authors.affiliation: Department of Radiation Oncology, Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY, USA.
authors.forename: Wolfgang A
authors.initials: WA
authors.lastname: Tomé
keywords: abdominal irradiation; dose response; histological analysis; radiation-induced gastrointestinal syndrome; small animal radiation research