Commissioning and evaluation of a third-party 6 degrees-of-freedom couch used in radiotherapy Journal Article


Authors: Chan, M. F.; Lim, S. B.; Li, X.; Tang, X.; Zhang, P.; Shi, C.
Article Title: Commissioning and evaluation of a third-party 6 degrees-of-freedom couch used in radiotherapy
Abstract: PURPOSES: The newly released Protura 6 degrees-of-freedom couch (CIVCO) has limited quality assurance protocols and pertinent publications. Herein, we report our experiences of the Protura system acceptance, commissioning, and quality assurance. METHODS: The Protura system integration was tested with peripheral equipment on the following items: couch movement range limit, 6 degrees-of-freedom movement accuracy, weight test and couch sagging, system connection with Linac, isocentricity of couch and rotation alignment, kV and cone-beam computed tomography imaging of HexaCHECK with MIMI phantom (Standard Imaging), and an in-house custom 6 degrees-of-freedom quality assurance phantom. A couch transmission measurement was also performed. RESULTS: The vertical, longitudinal, and lateral ranges of the 6 degrees-of-freedom couch pedestal are 43.9 to 0.0 cm, 24.6 to 149.5 cm, -20.6 to 20.7 cm, respectively. The couch movement accuracy was within 1 mm in all directions. The couch sagging with a 200 lbs (∼91 kg) evenly distributed object is 1.0 cm and 0.4° pitch in the distal end of the couch. The isocentricity of the couch was about 0.5 mm in diameter of all crosshair projections on the couch isocenter level, and the largest couch rotation alignment observed was (0.3°) at the couch angle of 90°. The deviation from the reference position (zero position) of the HexaCHECK phantom, measured by matching the cone-beam computed tomography with the reference planning computed tomography, was found to be below 0.2 mm in the anterior-posterior and right-left dimensions, 0.4 mm in superior-inferior dimension, and 0.1° in roll, pitch, and yaw directions. CONCLUSIONS: A 6 degrees-of-freedom quality assurance phantom is helpful for the commissioning and routine quality assurance tests. Due to the third-party integration with Linac, the system is prone to "double-correction" errors. A rigorous quality assurance program is the key to a successful clinical implementation of the Protura system.
Keywords: radiotherapy; commissioning; 6d couch; acceptance test; protura system
Journal Title: Technology in Cancer Research & Treatment
Volume: 18
ISSN: 1533-0346
Publisher: Sage Publications, Inc.  
Date Published: 2019-01-01
Language: English
DOI: 10.1177/1533033819870778
PUBMED: 31434547
PROVIDER: scopus
PMCID: PMC6704415
DOI/URL:
Notes: Source: Scopus
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  1. Maria F Chan
    192 Chan
  2. Seng Boh Lim
    93 Lim
  3. Xiaoli   Tang
    58 Tang
  4. Xiang   Li
    72 Li
  5. Chengyu   Shi
    33 Shi
  6. Peng Zhang
    12 Zhang