Motion management in particle therapy.

In this review article, we introduced the importance of "motion management" in advanced particle therapy. Several publications have reported that organ motion causes dose distribution disturbances due to interplay and blurring effects. Furthermore, motion can result in target dose miss and unwanted dose to healthy structures around the target. To avoid these problems, motion should be assessed and monitored prior and during treatment. In this review article, we give an overview about clinically available motion monitoring systems. Based on the acquired motion information an adequate motion mitigation technique should be chosen. This article reviews the clinical status of motion mitigation techniques like rescanning, gating and tracking. A limited number of centers have now started the treatment of targets in the thorax and abdomen using scanned particle beams. Therefore, the establishment of guidelines for motion monitoring and motion mitigation will be essential in the coming years.