In-Vivo Dosimetry for Small Animal Irradiation: A Preliminary Study

This study assessed applications for in-vivo dosimetry using a 3D printer-based, self-manufactured mouse immobilization device in a small field. The mouse immobilization device was created using a 3D printer (Makerbot Replicator, MakerBot Industries, Brooklyn, NY, USA) and consisted of the support flat, fixing units, sensor areas, and a build-up cap. Radio-photoluminescence glass dosimeters (RPLGD, GD-302M) were inserted at the upper left (UL), upper right (UR), lower left (LL), and lower right (LR) of the device at the center of the target. EBT3 film was inserted into the device at the top of the mouse's head. Irradiation planning was performed using the ECLIPSE system after a CT simulation of mice with an immobilization device. The mice were irradiated 5 times at a dose 180 cGy with 6 MV X-rays. The dose measurements from the RPLGDs and films were compared with the doses calculated in the Eclipse system. The percentage differences between the Radiation Treatment Planning (RTP) System and RPLGD measurements were 5.56 ± 3.90%, 6.52 ± 5.32%, 10.0 ± 8.97%, and 15.9 ± 17.5% at the UL, UR, LL, and LR positions, respectively. The gamma passing rate of all film measurements exceeded 90% in the 2%/2 mm range. The error values of the 3rd measurements were outliers due to the set up. With the exception of the 3rd measurements, the percentage difference decreased to 4–7%. In this study, we evaluated the applicability of a mouse immobilization device in a small field. We performed in-vivo dosimetry using RPLGD and EBT3 film; this approach may be helpful for using radiation to accurately analyze results in animal studies.