Premium
SU‐E‐T‐88: Acceptance Testing and Commissioning Measurements of a Newly Released InCiseâ„¢ Multileaf Collimator for CyberKnife M6â„¢ System
Author(s) -
Huq M Saiful,
Ozhasoglu C,
Jang S,
Hwang M,
Heron D,
Lalonde R
Publication year - 2015
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4924449
Subject(s) - multileaf collimator , collimator , cyberknife , nuclear medicine , dosimetry , acceptance testing , imaging phantom , radiosurgery , physics , materials science , optics , medical physics , medicine , beam (structure) , computer science , radiation therapy , linear particle accelerator , surgery , software engineering
Purpose: Accuray recently released a new collimator, the InCise™ Multileaf Collimator (MLC), for clinical use with the CyberKnife M6™ System. This work reports the results of acceptance testing and commissioning measurements for this collimator. Methods: The MLC consists of 41 pairs of 2.5 mm wide leaves projecting a clinical maximum field size of 110 mm × 97.5 mm at 800 mm SAD. The leaves are made of tungsten, 90 mm in height and tilted by 0.5 degree. The manufacturer stated leaf positioning accuracy and reproducibility are 0.5 mm and 0.4 mm respectively at 800 mm SAD. The leaf over‐travel is 100% with full interdigitation capability. Acceptance testing included, but are not limited to, the verification of the specifications of various parameters described above, leakage measurements and end‐to‐end tests. Dosimetric measurements included, but not limited to, measurements of output factors, open beam profiles, tissue‐phantom ratios, beam flatness and symmetry, and patient specific QA. Results: All measurements were well within the manufacturer specifications. The values of output factors ranged from 0.804 (smallest field size of 7.6 mm × 7.5 mm) to 1.018 (largest field size of 110.0 mm × 97.5 mm). End‐to‐end test results for the various tracking modes are: Skull (0.27mm), fiducial (0.16mm), Xsight Spine (0.4mm), Xsight Lung (0.93 mm) and Synchrony (0.43mm). Measured maximum and average leakage was 0.37% and 0.3%, respectively. Patient‐specific QA measurements with chamber were all within 5% absolute dose agreement, and film measurements all passed 2%/2mm gamma evaluation for more than 95% of measurement points. Conclusion: The presented results are the first set of data reported on the InCise™ MLC. The MLC proved to be very reliable and is currently in clinical use.