Program Information
An Advanced Deformable Lung Phantom for Analyzing the Dosimetric Impact of Respiratory Motion
D Shin*, S Kang , D Kim , T Kim , K Kim , M Cho , T Suh , Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Korea
Presentations
SU-G-BRA-13 (Sunday, July 31, 2016) 4:00 PM - 6:00 PM Room: Ballroom A
Purpose:
The difference between three-dimensional (3D) and four-dimensional (4D) dose is affected by factors such as tumor size and motion. To quantitatively analyze the effects of these factors, a phantom that can independently control for each factor is required. The purpose of this study is to develop a deformable lung phantom with the above attributes and evaluate characteristics.
Methods:
A phantom was designed to simulate diaphragm motion with amplitude in the range 1 to 7 cm and various periods of regular breathing. To simulate different size tumors, tumors were produced by pouring liquid silicone into custom molds created by a 3D printer. The accuracy of phantom diaphragm motion was assessed using calipers and protractor. To control tumor motion, tumor trajectories were evaluated using 4D computed tomography (CT), and diaphragm-tumor correlation curve was calculated by curve fitting method. Three-dimensional dose and 4D dose were calculated and compared according to tumor motion.
Results:
The accuracy of phantom diaphragm motion was less than 1 mm. Maximum tumor motion amplitudes in the left-right and anterior-posterior directions were 0.08 and 0.12 cm, respectively, in a 10 cm³ tumor, and 0.06 and 0.27 cm, respectively, in a 90 cm³ tumor. The diaphragm-tumor correlation curve showed that tumor motion in the superior-inferior direction was increased with increasing diaphragm motion. In the 10 cm³ tumor, the tumor motion was larger than the 90 cm³ tumor. According to tumor motion, variation of dose difference between 3D and 4D was identified.
Conclusion:
The developed phantom can independently control factors such as tumor size and motion. In potentially, this phantom can be used to quantitatively analyze the dosimetric impact of respiratory motion according to the factors that influence the difference between 3D and 4D dose.
Funding Support, Disclosures, and Conflict of Interest: This research was supported by the Mid-career Researcher Program through NRF funded by the Ministry of Science, ICT & Future Planning of Korea (NRF-2014R1A2A1A10050270) and by the Radiation Technology R&D program through the National Research Foundation of Korea funded by the Ministry of Science, ICT & Future Planning (No. 2013M2A2A7038291)
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