Small fields output factors measurements and correction factors determination for several detectors for a CyberKnife® and linear accelerators equipped with microMLC and circular cones

2013 ◽  
Vol 40 (7) ◽  
pp. 071725 ◽  
Author(s):  
C. Bassinet ◽  
C. Huet ◽  
S. Derreumaux ◽  
G. Brunet ◽  
M. Chéa ◽  
...  
Keyword(s):  
Correction Factors ◽  
Linear Accelerators ◽  
Small Fields ◽  
Output Factors

scholarly journals OC-0459: Small fields output factors and correction factors determination for a linac with circular cones

2016 ◽  
Vol 119 ◽  
pp. S216
Author(s):  
A. Girardi ◽  
C. Fiandra ◽  
E. Gallio ◽  
F.R. Giglioli ◽  
R. Ragona
Keyword(s):  
Correction Factors ◽  
Small Fields ◽  
Output Factors

Effect of inaccurate small field output factors on brain SRS plans

2022 ◽  
Author(s):  
Brennen Dobberthien ◽  
Fred Cao ◽  
Yingli Zhao ◽  
Eric Harvey ◽  
Genoveva Badragan
Keyword(s):  
External Beam Radiotherapy ◽  
Target Volume ◽  
Small Field ◽  
Correction Factors ◽  
Energy Agency ◽  
Small Field Dosimetry ◽  
Small Fields ◽  
Output Factors ◽  
Flattening Filter ◽  
The Impact

Abstract External beam radiotherapy often includes the use of field sizes 3 × 3 cm2 or less, which can be defined as small fields. Dosimetry is a difficult, yet important part of the radiotherapy process. The dosimetry of small fields has additional challenges, which can lead to treatment inconsistencies if not done properly. Most important is the use of an appropriate detector, as well as the application of the necessary corrections. The International Atomic Energy Agency and the American Association of Physicists in Medicine provide the International Code of Practice (CoP) TRS-483 for the dosimetry of small static fields used in external MV photon beams. It gives guidelines on how to apply small-field correction factors for small field dosimetry. The purpose of this study was to evaluate the impact of inaccurate small-field output factors on clinical brain stereotactic radiosurgery plans with and without applying the small-field correction factors as suggested in the CoP. Small-field correction factors for a Varian TrueBeam linear accelerator were applied to uncorrected relative dose factors. Uncorrected and corrected clinical plans were created with two different beam configurations, 6 MV with a flattening filter (6 WFF) and 6 MV without a flattening filter (6 FFF). For the corrected plans, the planning target volume mean dose was 1.6 ± 0.9% lower with p < 0.001 for 6 WFF and 1.8 ± 1.5% lower with p < 0.001 for 6 FFF. For brainstem, a major organ at risk, the corrected plans had a dose that was 1.6 ± 0.9% lower with p = 0.03 for 6 WFF and 1.8 ± 1.5% lower with p = 0.10 for 6 FFF. This represents a systematic error that should and can be corrected.

scholarly journals Field output factors for small fields: A large multicentre study

2021 ◽  
Vol 81 ◽  
pp. 191-196
Author(s):  
S. Dufreneix ◽  
J. Bellec ◽  
S. Josset ◽  
L. Vieillevigne
Keyword(s):  
Multicentre Study ◽  
Small Fields ◽  
Output Factors ◽  
Large Multicentre Study

scholarly journals Dosimetric Characterization of Small Radiotherapy Electron Beams Collimated by Circular Applicators with the New Microsilicon Detector

2022 ◽  
Vol 12 (2) ◽  
pp. 600
Author(s):  
Serenella Russo ◽  
Silvia Bettarini ◽  
Barbara Grilli Leonulli ◽  
Marco Esposito ◽  
Paolo Alpi ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Electron Beams ◽  
High Energy ◽  
Field Size ◽  
The Novel ◽  
Linear Accelerators ◽  
Depth Dose ◽  
Dosimetric Data ◽  
Output Factors ◽  
Dose Measurements

High-energy small electron beams, generated by linear accelerators, are used for radiotherapy of localized superficial tumours. The aim of the present study is to assess the dosimetric performance under small radiation therapy electron beams of the novel PTW microSilicon detector compared to other available dosimeters. Relative dose measurements of circular fields with 20, 30, 40, and 50 mm aperture diameters were performed for electron beams generated by an Elekta Synergy linac, with energy between 4 and 12 MeV. Percentage depth dose, transverse profiles, and output factors, normalized to the 10 × 10 cm2 reference field, were measured. All dosimetric data were collected in a PTW MP3 motorized water phantom, at SSD of 100 cm, by using the novel PTW microSilicon detector. The PTW diode E and the PTW microDiamond were also used in all beam apertures for benchmarking. Data for the biggest field size were also measured by the PTW Advanced Markus ionization chamber. Measurements performed by the microSilicon are in good agreement with the reference values for all the tubular applicators and beam energies within the stated uncertainties. This confirms the reliability of the microSilicon detector for relative dosimetry of small radiation therapy electron beams collimated by circular applicators.

Investigation of field output factors using IAEA-AAPM TRS-483 code of practice recommendations and Monte Carlo simulation for 6 MV photon beams

2021 ◽  
pp. 1-6
Author(s):  
Sumalee Yabsantia ◽  
Sivalee Suriyapee ◽  
Nakorn Phaisangittisakul ◽  
Sornjarod Oonsiri ◽  
Taweap Sanghangthum ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Field Method ◽  
Correction Factors ◽  
Photon Beams ◽  
Small Field Dosimetry ◽  
Code Of Practice ◽  
Edge Detectors ◽  
Output Factors ◽  
Measured Field ◽  
Mc Simulation

Abstract Introduction: This study aims to experimentally determine field output factors using the methodologies suggested by the IAEA-AAPM TRS-483 for small field dosimetry and compare with the calculation from Monte Carlo (MC) simulation. Methods: The IBA-CC01, Sun Nuclear EDGE and IBA-SFD detectors were employed to determine the uncorrected and the corrected field output factors for 6 MV photon beams. Measurements were performed at 100 cm source to axis distance, 10 cm depth in water, and the field sizes ranged from 1 × 1 to 10 × 10 cm2. The use of field output correction factors proposed by the TRS-483 was utilised to determine field output factors. The measured field output factors were compared to that calculated using the egs_chamber user code. Results: The decrease in the percentage standard deviation of the measured three detectors was observed after applying the field output correction factors. Measured field output factors using CC01 and EDGE detectors agreed with MC values within 3% for field sizes down to 1 × 1 cm2, except the SFD detector. Conclusions: The corrected field output factors agree with the calculation from MC, except the SFD detector. CC01 and EDGE are suitable for determining field output factors, while the SFD may need more implementation of the intermediate field method.

SU-E-T-266: New Improved Methods to Read Output Factors for Small Fields

2013 ◽  
Vol 40 (6Part14) ◽  
pp. 265-265
Author(s):  
C Smith ◽  
A Bacala ◽  
S Pella
Keyword(s):  
Small Fields ◽  
Output Factors ◽  
Improved Methods

SU-F-T-572: Small Fields Output Factors Measurement and Correction Factor Determination for Several Active and Passive Detectors

2016 ◽  
Vol 43 (6Part22) ◽  
pp. 3595-3595
Author(s):  
D Sharma ◽  
S Sharma ◽  
R Chowdhary ◽  
S Pilakkal ◽  
S Rashal
Keyword(s):  
Correction Factor ◽  
Small Fields ◽  
Output Factors
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