Dosimetric evaluation of respiratory gated volumetric modulated arc therapy for lung stereotactic body radiation therapy using 3D printing technology

• Published in: PloS one Vol. 13; no. 12; p. e0208685
• Main Authors: Yoon, KyoungJun, Jeong, Chiyoung, Kim, Sung-woo, Cho, Byungchul, Kwak, Jungwon, Kim, Su Ssan, Song, Si Yeol, Choi, Eun Kyung, Ahn, SeungDo, Lee, Sang-Wook
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 26.12.2018; Public Library of Science (PLoS)
• Subjects: 3-D printers; 3D printing; Acceptance criteria; Accuracy; Algorithms; Biology; Biology and Life Sciences; Cancer treatment; Computer simulation; Dosimeters; Dosimetry; Drug dosages; Engineering and technology; Equipment Design; Evaluation; Feasibility studies; Four-Dimensional Computed Tomography; Gating; Health physics; Heterogeneity; Humans; Lung - diagnostic imaging; Lung - physiopathology; Lung - radiation effects; Lung cancer; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - physiopathology; Lung Neoplasms - radiotherapy; Lungs; Management; Medical devices; Medical electronics; Medical equipment; Medical imaging; Medicine; Medicine and Health Sciences; Methods; Models, Anatomic; Monte Carlo simulation; Movement; Oncology; Patient-Specific Modeling; Patients; Phantoms, Imaging; Physical Sciences; Physics; Printing, Three-Dimensional; Radiation; Radiation dosimetry; Radiation therapy; Radiometry; Radiosurgery; Radiosurgery - instrumentation; Radiotherapy; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Intensity-Modulated - instrumentation; Research and Analysis Methods; Respiration; Respiratory physiology; Three dimensional bodies; Three dimensional printing; South Korea
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0208685

This study aimed to evaluate the dosimetric accuracy of respiratory gated volumetric modulated arc therapy (VMAT) for lung stereotactic body radiation therapy (SBRT) under simulation conditions similar to the actual clinical situation using patient-specific lung phantoms and realistic target movements. Six heterogeneous lung phantoms were fabricated using a 3D-printer (3DISON, ROKIT, Seoul, Korea) to be dosimetrically equivalent to actual target regions of lung SBRT cases treated via gated VMAT. They were designed to move realistically via a motion device (QUASAR, Modus Medical Devices, Canada). Using the lung phantoms and a homogeneous phantom (model 500-3315, Modus Medical Devices), film dosimetry was performed with and without respiratory gating for VMAT delivery (TrueBeam STx; Varian Medical Systems, Palo Alto, CA, USA). The measured results were analyzed with the gamma passing rates (GPRs) of 2%/1 mm criteria, by comparing with the calculated dose via the AXB and AAA algorithms of the Eclipse Treatment Planning System (version 10.0.28; Varian Medical Systems). GPRs were greater than the acceptance criteria 80% for all film measurements with the stationary and homogeneous phantoms in conventional QAs. Regardless of the heterogeneity of phantoms, there were no significant differences (p > 0.05) in GPRs obtained with and without target motions; the statistical significance (p = 0.031) was presented between both algorithms under the utilization of heterogeneous phantoms. Dosimetric verification with heterogeneous patient-specific lung phantoms could be successfully implemented as the evaluation method for gated VMAT delivery. In addition, it could be dosimetrically confirmed that the AXB algorithm improved the dose calculation accuracy under patient-specific simulations using 3D printed lung phantoms.