title: Technical Note: Partial body irradiation of mice using a customized PMMA apparatus and a clinical 3D planning/LINAC radiotherapy system.
abstract: OBJECTIVE
  In vivo radiobiology experiments involving partial body irradiation (PBI) of mice are of major importance because they allow for the evaluation of individual organ tolerance; overcoming current limitations of experiments using lower dose, whole body irradiation. In the current study, the authors characterize and validate an effective and efficient apparatus for multiple animal PBI, directed to the head, thorax, or abdomen of mice.
  
  
  METHODS
  The apparatus is made of polymethylmethacrylate and consists of a rectangular parallelepiped prism (40 cm × 16 cm × 8 cm), in which five holes were drilled to accomodate standard 60 ml syringes, each housing an unanesthetized, fully immobilized mouse. Following CT-scanning and radiotherapy treatment planning, radiation fields were designed to irradiate the head, thorax, or abdomen of the animal. Thermoluminescent dosimeters (TLDs) were used to confirm the treatment planning dosimetry for primary beam and scattered radiation.
  
  
  RESULTS
  Mice are efficiently placed into 60 ml syringes and immobilized, without the use of anesthetics. Although partial rotational movement around the longitudinal axis and a minor 2 mm forward/backward movement are permitted, this does not compromise the irradiation of the chosen body area. TLDs confirmed the dose values predicted by the treatment planning dosimetry, both for primary beam and scattered radiation.
  
  
  CONCLUSIONS
  The customized PMMA apparatus described and validated is cost-effective, convenient to use, and efficient in performing PBI without the use of anesthesia. The developed apparatus permits the isolated irradiation of the mouse head, thorax, and abdomen. Importantly, the apparatus allows the delivery of PBI to five mice, simultaneously, representing an efficient way to effectively expose a large number of animals to PBI through multiple daily fractions, simulating clinical radiotherapy treatment schedules.
authors.affiliation: Department of Radiotherapy-Oncology, Radiopathology and Radiobiology Unit, Medical School, Democritus University of Thrace, Alexandroupolis 68100, Greece.
authors.forename: Ilias V
authors.initials: IV
authors.lastname: Karagounis
authors.affiliation: Medical Physics Department, University General Hospital of Alexandroupolis, Alexandroupolis 68100, Greece.
authors.forename: Ioannis M
authors.initials: IM
authors.lastname: Abatzoglou
authors.affiliation: Department of Radiotherapy-Oncology, Radiopathology and Radiobiology Unit, Medical School, Democritus University of Thrace, Alexandroupolis 68100, Greece.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Koukourakis
mesh_terms: D000005:Abdomen / Q000528:radiation effects; D000818:Animals; D001522:Behavior, Animal; D004867:Equipment Design; D006257:Head / Q000528:radiation effects; D021621:Imaging, Three-Dimensional / Q000295:instrumentation* / Q000379:methods; D007103:Immobilization / Q000295:instrumentation* / Q000379:methods / Q000523:psychology; D008297:Male; D008807:Mice, Inbred BALB C; D009068:Movement; D019904:Polymethyl Methacrylate; D016634:Radiosurgery / Q000295:instrumentation* / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D061089:Radiotherapy, Image-Guided / Q000295:instrumentation* / Q000379:methods; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation / Q000379:methods; D013909:Thorax / Q000528:radiation effects; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods
chemical_list: D019904:Polymethyl Methacrylate