Dosimetry of Small Animal Precision Irradiators

This chapter discusses dose measurement and dosimetry in simple uniform phantoms, or phantoms with a shape somewhat representative of a small animal, with the possible exception of the PlastiMouse phantom which is a fairly accurate representation of a complete mouse. The beam diameter should enable covering the sensitive volume of the radiation detector. Ionization chambers are certainly the gold standard for absolute dosimetry, but also for relative dosimetry due to their small energy dependence. Radiochromic external beam therapy (EBT)-type films are extensively used for dosimetric purposes in radiation physics, mostly for quality assurance with respect to fluence-modulated radiotherapy, and recently also for small-field dosimetry. Polymer gels, one of the few "true" three-dimensional dosimeters, have been explored for dosimetry for more than a decade, mostly with respect to verifying fluence-modulated radiotherapy with high-energy photon beams.