부산대학교 도서관

• A further investigation of the clinical necessity of 4D optimization is warranted. • Benefits of 4D optimization in terms of higher robustness have been reported. • Many studies found that 3D robustly optimized plans were also suitable for treatments. • A need for consensus on 4D dose calculation and evaluation is identified. 4D multi-image-based (4D MIB) optimization is a form of robust optimization where different uncertainty scenarios, due to anatomy variations, are considered via multiple image sets (e.g., 4DCT). In this review, we focused on providing an overview of different 4D MIB optimization implementations, introduced various frameworks to evaluate the robustness of scanned particle therapy affected by breathing motion and summarized the existing evidence on the necessity of using 4D MIB optimization clinically. Expected potential benefits of 4D MIB optimization include more robust and/or interplay-effect-resistant doses for the target volume and organs-at-risk for indications affected by anatomical variations (e.g., breathing, peristalsis, etc.). Although considerable literature is available on the research and technical aspects of 4D MIB , clinical studies are rare and often contain methodological limitations, such as, limited patient number, motion amplitude, motion and delivery time structure considerations, number of repeat CTs, etc. Therefore, the data are not conclusive. In addition, multiple studies have found that robust 3D optimized plans result in dose distributions within the set clinical tolerances and, therefore, are suitable for a treatment of moving targets with scanned particle therapy. We, therefore, consider the clinical necessity of 4D MIB optimization, when treating moving targets with scanned particle therapy, as still to be demonstrated. [ABSTRACT FROM AUTHOR]