Advances in dual energy computed tomography approach for proton stopping power ratio computation in radiotherapy.

To address the sensitive and uncertain limitations of single-energy computed tomography (CT) calibration methods in computing proton stopping power ratio during treatment planning, different methods have been proposed using a dual energy CT approach. This paper reviews the most recent dual-energy CT approaches for computing proton stopping power ratio. These include image domain and projection domain methods. The advantages and uncertainties of these methods are analyzed based on existing studies. This paper highlights recent advances in dual energy CT, discussing their implementation, advantages, limitations, and potential for clinical adoption.