Room: AAPM ePoster Library
Purpose: The X-Rad 320 biological irradiator is a cabinet irradiator used for delivering whole-body doses to mice. Dose rate estimates for various setups inside the X-Rad 320 do not consider corrections based on the size of the mouse. This work aims to use 3D-printed mouse-like phantoms to determine the effect of mouse size on dose delivered to adult mice from an X-Rad 320 irradiator.
Methods: Five mouse-like phantoms were 3D-printed with varying volumes characteristic of the range of sizes of adult mice. Three thermoluminescent dosimeter (TLD) microcubes were placed inside each phantom using 3D-printed holders and were used to measure dose from an X-Rad 320 biological irradiator. The dose from the three TLDs was averaged, and the irradiations were performed five times for each phantom. The tube potential was 320 kVp, and the time-current product was 812.5 mAs for each irradiation, which are typical parameters used in conventional radiobiological experiments involving mice. The phantoms were placed on a polycarbonate slab to provide consistent backscatter conditions. The slab surface was 50 cm from the source and the field size was 20 x 20 cm² at the slab surface. The central TLD was along the central axis of the beam. Output factors (OFs) were calculated for each phantom normalized to the dose delivered to the phantom of central volume.
Results: The OFs ranged from 0.987 to 1.000 among the five phantoms ranging from 22 cc to 34 cc. Each OF was within the relative standard uncertainty of the measurements of unity.
Conclusion: This work indicates that the relative dose delivered to the abdomen of the mouse-like phantom is close to unity across the range of mouse sizes investigated in this study. This is encouraging for radiobiologists who wish to compare results from different mouse sizes for various studies involving the X-Rad 320.