Room: AAPM ePoster Library
Purpose: lung respiration will influence the accuracy of dose delivery and deformable image registration (DIR) in thoracic radiotherapy, resulting in radiation induced lung injury (RILI). We designed and fabricated a dynamic anthropomorphic thorax phantom for the dose verification and DIR validation in thoracic radiotherapy.
Methods: The dynamic anthropomorphic thorax phantom consists of anatomical structures and driving device. We fabricated it based on the following steps: Firstly, we generated a 3D STL model for each anatomical structure in thorax using an anonymous patient’s CT images on Mimics software, and processed them on Meshmixer software so that the files can be used for 3d printing. Secondly, the lungs, tumor, bones, tissue, airways and skin were fabricated using radiological equivalent materials by 3D printing technology and pour forming technology. A total of ten markers were placed on the lungs and tumor. Finally, the airways of bilateral lungs were connected to the programmable driving device composed of stepper motor, cylinder and display screen. The phantom was scanned using a Hitachi CT scanner, which contributed the anonymous patient’s CT images. An experienced radiologist checked whether the phantom can mimic the human body.
Result: This phantom can highly mimic the anatomical structures of thorax. The average CT value of each structure was similar with that of the human body (bone: 256; tissue: 54; tumor: 66; lung: -1000). The thorax phantom can accurately simulate human breathing movement and the general changes of chest; the pulmonary ventilation and respiratory rate were simultaneously displayed on the screen.
Conclusion: This study designed and fabricated a dynamic thorax phantom that can simulate both the anatomical structures and changes in organs with respiration. This phantom can be used for the quality control of dose delivery and DIR in radiotherapy, thus may reduce the incidence of RILI.
Funding Support, Disclosures, and Conflict of Interest: This study was supported by the Shandong Province Key Research and Development Program (2017GSF218075), the National Undergraduate Training Program for Innovation and Entrepreneurship of China (201910439014) and Taishan Scholars Program of Shandong Province.