BACKGROUND: The accuracy of relative stopping power (RSP) is a critical aspect for safe treatment planning in proton therapy. Dual-energy CT (DECT) has the ability to estimate RSP more accurately than conventional single-energy CT (SECT) due to its improved material separation. RSP accuracy is commonly determined in homogeneous phantom material as it can be more challenging to determine in heterogeneous biological tissues. Proton CT (pCT) is a modality that directly determines RSP and can be used as a comparative benchmark for evaluating the RSP accuracy of DECT and SECT derived values across homogeneous and heterogeneous material.
PURPOSE: In this study, DECT was compared to SECT in both homogeneous phantom inserts of known RSP and heterogeneous tissue samples of unknown RSP using pCT as a quantitative reference. The purpose of this study was to assess the ability of DECT to improve RSP estimation over SECT in unknown RSP of heterogeneous tissues.
METHODS: A variety of homogeneous...