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Title: SU-F-T-529: Dosimetric Investigation of a Rotating Gamma Ray System for ImagedGuided Modulated Arc Radiotherapy

Abstract

Purpose: Because of their effectiveness and efficiency, rotational arc radiotherapy (MAT) techniques have been developed on both specialty machines such as Tomotherapy and conventional linear accelerators. This work investigates a new rotating Gamma therapy system for image guided MAT and SBRT of intra/extracranial tumors. Methods: The CyberMAT system (Cyber Medical Corp., China) consists of a ring gantry with a gamma source (effective source size 1cm and 1.7cm respectively), a 120-leaf MLC, a kV CBCT and an EPID. The treatment couch provides 6-degrees-of-freedom motion compensation and the kV CBCT system has a spatial resolution of 0.4mm for target localization. The maximum dose rate is >4.0 Gy/min and the maximum field size is 40cm × 40cm. Monte Carlo simulations were used to compute dose distributions and compare with measurements. A retrospective study of 125 previously treated SBRT patients was performed to evaluate the dosimetric characteristics of CyberMAT in comparison with existing VMAT systems. Results: Monte Carlo results confirmed the CyberMAT design parameters including output factors and 3D dose distributions. Its beam penumbra is 5mm to 10mm for field sizes 1cm to 10cm, respectively and its isocenter accuracy is <0.5mm. Compared to the 6 MV photons of Tomotherapy and conventional linacs, Cobalt beamsmore » produce lower-energy secondary electrons that exhibit better dose properties in low-density lung tissues. Cobalt beams are ideal for peripheral lung tumors with half-arc arrangements to spare the opposite lung and other critical structures. Superior dose distributions have been obtained for brain, head and neck, breast, spine and lung tumors with half/full arc arrangements. Conclusion: Because of the unique dosimetric properties of Cobalt sources and its accurate stereotaxy/dose delivery CyberMAT is ideally suited for image guided MAT and SBRT. Full-arc arrangements are superior for brain and H&N treatments while half-arc arrangements produce best dose distributions for thoracic tumors.« less

Authors:
; ; ;  [1];  [2]
  1. Fox Chase Cancer Center, Philadelphia, PA (United States)
  2. Cyber Medical Inc, Xian (China)
Publication Date:
OSTI Identifier:
22649113
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 43; Journal Issue: 6; Other Information: (c) 2016 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; 61 RADIATION PROTECTION AND DOSIMETRY; BEAMS; COBALT; COMPUTERIZED SIMULATION; COMPUTERIZED TOMOGRAPHY; CT-GUIDED RADIOTHERAPY; DOSE RATES; GAMMA RADIATION; GAMMA SOURCES; LINEAR ACCELERATORS; LUNGS; MAMMARY GLANDS; MONTE CARLO METHOD; NEOPLASMS; RADIATION DOSE DISTRIBUTIONS; SPATIAL RESOLUTION

Citation Formats

Ma, C, Chibani, O, Eldib, A, Chen, L, and Li, J. SU-F-T-529: Dosimetric Investigation of a Rotating Gamma Ray System for ImagedGuided Modulated Arc Radiotherapy. United States: N. p., 2016. Web. doi:10.1118/1.4956714.
Ma, C, Chibani, O, Eldib, A, Chen, L, & Li, J. SU-F-T-529: Dosimetric Investigation of a Rotating Gamma Ray System for ImagedGuided Modulated Arc Radiotherapy. United States. doi:10.1118/1.4956714.
Ma, C, Chibani, O, Eldib, A, Chen, L, and Li, J. Wed . "SU-F-T-529: Dosimetric Investigation of a Rotating Gamma Ray System for ImagedGuided Modulated Arc Radiotherapy". United States. doi:10.1118/1.4956714.
@article{osti_22649113,
title = {SU-F-T-529: Dosimetric Investigation of a Rotating Gamma Ray System for ImagedGuided Modulated Arc Radiotherapy},
author = {Ma, C and Chibani, O and Eldib, A and Chen, L and Li, J},
abstractNote = {Purpose: Because of their effectiveness and efficiency, rotational arc radiotherapy (MAT) techniques have been developed on both specialty machines such as Tomotherapy and conventional linear accelerators. This work investigates a new rotating Gamma therapy system for image guided MAT and SBRT of intra/extracranial tumors. Methods: The CyberMAT system (Cyber Medical Corp., China) consists of a ring gantry with a gamma source (effective source size 1cm and 1.7cm respectively), a 120-leaf MLC, a kV CBCT and an EPID. The treatment couch provides 6-degrees-of-freedom motion compensation and the kV CBCT system has a spatial resolution of 0.4mm for target localization. The maximum dose rate is >4.0 Gy/min and the maximum field size is 40cm × 40cm. Monte Carlo simulations were used to compute dose distributions and compare with measurements. A retrospective study of 125 previously treated SBRT patients was performed to evaluate the dosimetric characteristics of CyberMAT in comparison with existing VMAT systems. Results: Monte Carlo results confirmed the CyberMAT design parameters including output factors and 3D dose distributions. Its beam penumbra is 5mm to 10mm for field sizes 1cm to 10cm, respectively and its isocenter accuracy is <0.5mm. Compared to the 6 MV photons of Tomotherapy and conventional linacs, Cobalt beams produce lower-energy secondary electrons that exhibit better dose properties in low-density lung tissues. Cobalt beams are ideal for peripheral lung tumors with half-arc arrangements to spare the opposite lung and other critical structures. Superior dose distributions have been obtained for brain, head and neck, breast, spine and lung tumors with half/full arc arrangements. Conclusion: Because of the unique dosimetric properties of Cobalt sources and its accurate stereotaxy/dose delivery CyberMAT is ideally suited for image guided MAT and SBRT. Full-arc arrangements are superior for brain and H&N treatments while half-arc arrangements produce best dose distributions for thoracic tumors.},
doi = {10.1118/1.4956714},
journal = {Medical Physics},
number = 6,
volume = 43,
place = {United States},
year = {Wed Jun 15 00:00:00 EDT 2016},
month = {Wed Jun 15 00:00:00 EDT 2016}
}