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Kang Y, Shen J, Liu W, Taylor PA, Mehrens HS, Ding X, Hu Y, Tryggestad E, Keole SR, Schild SE, Wong WW, Fatyga M, Bues M. Impact of planned dose reporting methods on Gamma pass rates for IROC lung and liver motion phantoms treated with pencil beam scanning protons. Radiat Oncol 2019; 14:108. [PMID: 31208439 PMCID: PMC6580526 DOI: 10.1186/s13014-019-1316-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 06/06/2019] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The purpose of this study is to evaluate the impact of two methods of reporting planned dose distributions on the Gamma analysis pass rates for comparison with measured 2D film dose and simulated delivered 3D dose for proton pencil beam scanning treatment of the Imaging and Radiation Oncology Core (IROC) proton lung and liver mobile phantoms. METHODS AND MATERIALS Four-dimensional (4D) computed-tomography (CT) image sets were acquired for IROC proton lung and liver mobile phantoms, which include dosimetry inserts that contains targets, thermoluminescent dosimeters and EBT2 films for plan dose verification. 4DCT measured fixed motion magnitudes were 1.3 and 1.0 cm for the lung and liver phantoms, respectively. To study the effects of motion magnitude on the Gamma analysis pass rate, three motion magnitudes for each phantom were simulated by creating virtual 4DCT image sets with motion magnitudes scaled from the scanned phantom motion by 50, 100, and 200%. The internal target volumes were contoured on the maximum intensity projection CTs of the 4DCTs for the lung phantom and on the minimum intensity projection CTs of the 4DCTs for the liver phantom. Treatment plans were optimized on the average intensity projection (AVE) CTs of the 4DCTs using the RayStation treatment planning system. Plan doses were calculated on the AVE CTs, which was defined as the planned AVE dose (method one). Plan doses were also calculated on all 10 phase CTs of the 4DCTs and were registered using target alignment to and equal-weight-summed on the 50% phase (T50) CT, which was defined as the planned 4D dose (method two). The planned AVE doses and 4D doses for phantom treatment were reported to IROC, and the 2D-2D Gamma analysis pass rates for measured film dose relative to the planned AVE and 4D doses were compared. To evaluate motion interplay effects, simulated delivered doses were calculated for each plan by sorting spots into corresponding respiratory phases using spot delivery time recorded in the log files by the beam delivery system to calculate each phase dose and accumulate dose to the T50 CTs. Ten random beam starting phases were used for each beam to obtain the range of the simulated delivered dose distributions. 3D-3D Gamma analyses were performed to compare the planned 4D/AVE doses with simulated delivered doses. RESULTS The planned 4D dose matched better with the measured 2D film dose and simulated delivered 3D dose than the planned AVE dose. Using planned 4D dose as institution reported planned dose to IROC improved IROC film dose 2D-2D Gamma analysis pass rate from 92 to 96% on average for three films for the lung phantom (7% 5 mm), and from 92 to 94% in the sagittal plane for the liver phantom (7% 4 mm), respectively, compared with using the planned AVE dose. The 3D-3D Gamma analysis (3% 3 mm) pass rate showed that the simulated delivered doses for lung and liver phantoms using 10 random beam starting phases for each delivered beam matched the planned 4D dose significantly better than the planned AVE dose for phantom motions larger than 1 cm (p ≤ 0.04). CONCLUSIONS It is recommended to use the planned 4D dose as the institution reported planned dose to IROC to compare with the measured film dose for proton mobile phantoms to improve film Gamma analysis pass rate in the IROC credentialing process.
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Affiliation(s)
- Yixiu Kang
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054 USA
- Seattle Cancer Care Alliance Proton Therapy Center, 1570 N 115th St, Seattle, WA 98133 USA
| | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054 USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054 USA
| | - Paige A. Taylor
- The Imaging and Radiation Oncology Core Houston Quality Assurance Center, The University of Texas MD Anderson Cancer Center, Unit 607, 1515 Holcombe Blvd, Houston, TX 77030 USA
| | - Hunter S. Mehrens
- The Imaging and Radiation Oncology Core Houston Quality Assurance Center, The University of Texas MD Anderson Cancer Center, Unit 607, 1515 Holcombe Blvd, Houston, TX 77030 USA
| | - Xiaoning Ding
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054 USA
| | - Yanle Hu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054 USA
| | - Erik Tryggestad
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905 USA
| | - Sameer R. Keole
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054 USA
| | - Steven E. Schild
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054 USA
| | - William W. Wong
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054 USA
| | - Mirek Fatyga
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054 USA
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054 USA
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Sala IM, Nair GB, Maurer B, Guerrero TM. High frequency percussive ventilation for respiratory immobilization in radiotherapy. Tech Innov Patient Support Radiat Oncol 2018; 9:8-12. [PMID: 32095589 PMCID: PMC7033809 DOI: 10.1016/j.tipsro.2018.11.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 11/08/2018] [Accepted: 11/19/2018] [Indexed: 11/30/2022] Open
Abstract
HFPV maybe a tool for immobilizing thoracic targets in radiotherapy. The procedure itself was well tolerated and well complied. Chest wall motion was significantly reduced by greater than 60%. HFPV can be greatly advantageous, particularly for SBRT and PBS proton therapy. Duty cycle under HFPV was significantly higher than conventional methods. The appropriate interface can lead to extensive HFPV prolonged times.
High frequency percussive ventilation (HFPV) employs high frequency low tidal volumes (100–400 bursts/min) to provide respiration in awake patients while simultaneously reducing respiratory motion. The purpose of this study is to evaluate HFPV as a technique for respiratory motion immobilization in radiotherapy. In this study fifteen healthy volunteers (age 30–75 y) underwent HFPV using three different oral interfaces. We evaluated each HFPV oral interface device for compliance, ease of use, comfort, geometric interference, minimal chest wall motion, duty cycle and prolonged percussive time. Their chest wall motion was monitored using an external respiratory motion laser system. The percussive ventilations were delivered via an air driven pneumatic system. All volunteers were monitored for PO2 and tc-CO2 with a pulse oximeter and CO2 Monitoring System. A total of N = 62 percussive sessions were analyzed from the external respiratory motion laser system. Chest-wall motion was well tolerated and drastically reduced using HFPV in each volunteer evaluated. As a result, we believe HFPV may provide thoracic immobilization during radiotherapy, particularly for SBRT and pencil beam scanning proton therapy.
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Affiliation(s)
- Ina M Sala
- William Beaumont Hospital, Department of Radiation Oncology, Royal Oak, MI, United States.,Wayne State University, Karmanos Cancer Center, Detroit, MI, United States
| | - Girish B Nair
- William Beaumont Hospital, Department of Pulmonary Critical Care, Royal Oak, MI, United States.,Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - Beverly Maurer
- William Beaumont Hospital, Department of Pulmonary Physiology, Royal Oak, MI, United States
| | - Thomas M Guerrero
- William Beaumont Hospital, Department of Radiation Oncology, Royal Oak, MI, United States.,Oakland University William Beaumont School of Medicine, Rochester, MI, United States
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