Dose estimation of animal experiments at the THOR BNCT beam by NCTPlan and Xplan

• This study presents the new BNCT treatment planning system Xplan for animal experiments.
• Xplan is based on a pixel-to-pixel conversion which has the same resolution as the CT images.
• NCTplan and a simplified geometry for rat were used for the sake of comparison.
• The spatial resolution applied in calculation is crucial to the reliability of estimated dose.

Dose estimation of animal experiments affects many subsequent derived quantities, such as RBE and CBE values. It is important to ensure the trustiness of calculated dose of the irradiated animals. However, the dose estimation was normally calculated using simplified geometries and tissue compositions, which led to rough results. This paper introduces the use of treatment planning systems NCTplan and Xplan for the dose estimation. A mouse was taken as an example and it was brought to hospital for micro-PET/CT scan. It was found that the critical organ doses of an irradiated mouse calculated by simplified model were unreliable in comparison to Xplan voxel model. The difference could reach the extent of several tenths percent. It is recommended that a treatment planning system should be introduced to future animal experiments to upgrade the data quality.