Establishment of a small animal setup for multimodal imaging and irradiation

For preclinical cancer research, dedicated small animal imaging and irradiation devices are increasingly gaining importance to examine experimental tumors and normal tissue models. We designed a special small animal bed, which is intended to be used for multimodal imaging (e.g. MRI, CT, PET) and image-guided treatment with different radiation types (e.g. photons, protons). The multimodality small animal bed was constructed with CAD software and produced with a 3D printer using the fused deposition modeling procedure. The bed is made of thin acrylonitrile butadiene styrene (ABS), which is fully compatible with magnetic fields, barely influence radiation and is chemically resistant against most frequently used disinfectants. To facilitate proper positioning and alignment of the animal, the bed contains a tooth bar and ear pins for cranial fixation as well as a detachable distal foot holder for the hind leg. For inhalation anesthesia, a respective mask is integrated. To avoid hypothermia, the bed is supplied with a controllable stream of HEPA-filtered warm air. Furthermore, the respiration of the animal can be monitored during the experiment using a respiratory cushion. Suitability of the prototype was tested for photon and proton irradiation as well as CT imaging and proton radiography. In conclusion, the designed multimodality bed enables standardized positioning of small animals and provides integrated solutions for their anesthesia, warming and monitoring. Ist use for multimodal monitoring and image-guided irradiation of experimental tumors will simplify the workflow and image analyses for preclinical radiooncological investigations.