TY - JOUR
T1 - Output factor measurements with multiple detectors in CyberKnife® Robotic Radiosurgery System
AU - Manavalan, Muthukumaran
AU - Durai, Manigandan
AU - Narayanasamy, Ganesh
AU - Stathakis, Sotirios
AU - Godson, Henry Finlay
AU - Subramani, Vikraman
N1 - Publisher Copyright:
© 2021 Journal of Cancer Research and Therapeutics.
PY - 2021/7/1
Y1 - 2021/7/1
N2 - Aim: The aim of this study was to measure and compare the output factor (OF) of a CyberKnife Robotic Radiosurgery System with eight different small field detectors and validate with Technical Report Series (TRS) report 483. Background: Accurate dosimetry of CyberKnife system is limited due to the challenges in small field dosimetry. OF is a vital dosimetric parameter used in the photon beam modeling and any error would affect the dose calculation accuracy. Materials and Methods: In this study, the OF was measured with eight different small-field detectors for the 12 IRIS collimators at 800 mm SAD setup at 15 mm depth. The detectors used were PTW 31016 PinPoint 3D, IBA PFD shielded diode, IBA EFD unshielded diode, IBA SFD unshielded diode (stereotactic), PTW 60008 shielded diode, PTW 60012 unshielded diode, PTW 60018 unshielded diode (stereotactic), and PTW 60019 CVD diamond detector. OF was obtained after correcting for field output correction factors from IAEA TRS No. 483. Results: The field OFs in CyberKnife are derived from the measured data by applying the correction factors from Table 23 in TRS 483 for the eight small field detectors. These field OFs matched within 2% of peer-reviewed published values. The range and standard deviation showed a decreasing trend with collimator diameter. Conclusion: The field OF obtained after applying the appropriate correction factor from TRS 483 matched well with the peer-reviewed published OFs. The inter-detector variation showed a decreasing trend with increasing collimator field size. This study gives physicists confidence in measuring field OFs while using small field detectors mentioned in this work.
AB - Aim: The aim of this study was to measure and compare the output factor (OF) of a CyberKnife Robotic Radiosurgery System with eight different small field detectors and validate with Technical Report Series (TRS) report 483. Background: Accurate dosimetry of CyberKnife system is limited due to the challenges in small field dosimetry. OF is a vital dosimetric parameter used in the photon beam modeling and any error would affect the dose calculation accuracy. Materials and Methods: In this study, the OF was measured with eight different small-field detectors for the 12 IRIS collimators at 800 mm SAD setup at 15 mm depth. The detectors used were PTW 31016 PinPoint 3D, IBA PFD shielded diode, IBA EFD unshielded diode, IBA SFD unshielded diode (stereotactic), PTW 60008 shielded diode, PTW 60012 unshielded diode, PTW 60018 unshielded diode (stereotactic), and PTW 60019 CVD diamond detector. OF was obtained after correcting for field output correction factors from IAEA TRS No. 483. Results: The field OFs in CyberKnife are derived from the measured data by applying the correction factors from Table 23 in TRS 483 for the eight small field detectors. These field OFs matched within 2% of peer-reviewed published values. The range and standard deviation showed a decreasing trend with collimator diameter. Conclusion: The field OF obtained after applying the appropriate correction factor from TRS 483 matched well with the peer-reviewed published OFs. The inter-detector variation showed a decreasing trend with increasing collimator field size. This study gives physicists confidence in measuring field OFs while using small field detectors mentioned in this work.
KW - CyberKnife
KW - Output factor
KW - Small field dosimetry
KW - Stereotactic field
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U2 - 10.4103/jcrt.JCRT_962_20
DO - 10.4103/jcrt.JCRT_962_20
M3 - Article
C2 - 34528534
AN - SCOPUS:85115697486
VL - 17
SP - 870
EP - 874
JO - Journal of Cancer Research and Therapeutics
JF - Journal of Cancer Research and Therapeutics
SN - 0973-1482
IS - 4
ER -