4D calculation and biological dosimetry of the RBE-weighted dose for scanned carbon ion beam therapy

摘要

he software treatment planning for particles (TRiP) was extended by the functionality to calculate the clinically relevant RBE-weighted dose for scanned ion beams in the presence of motion. Calculations are based on 4D-CT and deformable registration. The underlying biological model is the local effect model. To validate the dose calculation algorithm experimentally a dedicated motion phantom for biological dosimetry was developed. In-vitro cell survival measurements were performed with a target dose of 9 Gy (RBE). The mean dose difference between the calculation and the measurement and its standard deviation was obtained to be 155±400 mGy (RBE). This validates the calculation within the measurement error of 519 mGy (RBE).