Clinical necessity of multi-image based (4DMIB) optimization for targets affected by respiratory motion and treated with scanned particle therapy – A comprehensive review


Clinical necessity of multi-image based (4DMIB) optimization for targets affected by respiratory motion and treated with scanned particle therapy – A comprehensive review

Knopf, A.-C.; Czerska, K.; Fracchiolla, F.; Graeff, C.; Molinelli, S.; Rinaldi, I.; Rucincki, A.; Sterpin, E.; Stützer, K.; Trnkova, P.; Zhang, Y.; Chang, J. Y.; Giap, H.; Liu, W.; Schild, S. E.; Simone Ii, C. B.; Lomax, A. J.; Meijers, A.

4D multi-image-based (4DMIB) 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 4DMIB optimization implementations, introduced var-
ious frameworks to evaluate the robustness of scanned particle therapy affected by breathing motion and
summarized the existing evidence on the necessity of using 4DMIB optimization clinically. Expected
potential benefits of 4DMIB 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
4DMIB, 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 opti-
mized 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 4DMIB optimization, when treating moving targets with scanned particle therapy, as still to be
demonstrated.

Keywords: Proton therapy; 4D optimization; Multi-image-based optimization; Motion management

Permalink: https://www.hzdr.de/publications/Publ-35116
Publ.-Id: 35116