부산대학교 도서관

An MRI-linac system provides directMRIfeedback and with that the possibility of adapting radiation treatments to the actual tumour position. This paper addresses the use of fast 1D MRI, pencil-beam navigators, for this feedback. The accuracy of using navigators was determined on a moving phantom. The possibility of organ tracking and breath-hold monitoring based on navigator guidance was shown for the kidney. Navigators are accurate within 0.5 mm and the analysis has aminimal time lag smaller than 30 ms as shown for the phantom measurements. The correlation of 2D kidney images and navigators shows the possibility of complete organ tracking. Furthermore the breath-holdmonitoring of the kidney is accurate within 1.5 mm, allowing gated radiotherapy based on navigator feedback. Navigators are a fast and precise method for monitoring and real-time tracking of anatomical landmarks. As such, they provide direct MRI feedback on anatomical changes for more precise radiation delivery. [ABSTRACT FROM AUTHOR]