Dosimetric accuracy and radiobiological implications of ion computed tomography for proton therapy treatment planning.

Dosimetric accuracy and radiobiological implications of ion computed tomography for proton therapy treatment planning. Phys Med Biol. 2019 Mar 14;: Authors: Meyer S, Kamp F, Tessonnier T, Mairani A, Belka C, Carlson DJ, Gianoli C, Parodi K Abstract Ion computed tomography (iCT) represents a potential replacement for X-ray CT (xCT) in ion therapy treatment planning to reduce range uncertainties, inherent in the semi-empirical conversion of xCT information into relative stopping power (RSP). In this work, we aim at quantifying the increase in dosimetric accuracy associated with using proton-, helium- and carbon-iCT compared to conventional xCT for clinical scenarios in proton therapy. Three cases imaged with active beam-delivery using an ideal single-particle-tracking detector were investigated using FLUKA Monte-Carlo simulations. The RSP accuracy of the iCTs was evaluated against the ground truth at similar physical dose. Next, the resulting dosimetric accuracy was investigated by using the RSP images as patient model in proton therapy treatment planning, in comparison to common uncertainties associated to xCT. Finally, changes in relative biological effectiveness (RBE) with iCT particle type/spectrum were investigated by incorporating the repair-misrepair-fixation (RMF) model into FLUKA, to enable first insights on the associated biological imaging dose. Helium-CT provided the lowest overall RSP error, whereas carbon-CT offered the h...
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research