ESTRO 2021 Abstract Book

S665

ESTRO 2021

a deformable diaphragm and peritoneum (Fig. 1). The abdominal cavity was filled with 18l of 0.4% agarose to allow organ movement. Liver and kidney models were manufactured with a NiDTPA-KCl-Agarose mixture [2]. For evaluation of T1 and T2 relaxation time, quantitavive MRI measurement were conducted with a Magnetom AERA 1.5 T. HU value were quantified via 3D volume analysis using a Siemens Somaton CT Scanner. To move the diaphragm and underlying organs two adjustable concave shaped actuators were placed, using a 3D printed locking mechanism. Furthermore, a hydraulic system was attached to the actuators connected to a linear stage unit which was controlled using a programmable logic controller (PLC). Breathing motion for input trajectory was extracted from segmented 4D MRI patient data (Fig. 2). The segmented data was translated to the movement of the actuators of the phantom to simulate diaphragm breathing movement.