SUET601: Output Factor Calculation of Irregular Shape Electron Cutout at Extended SSD
Abstract
Purpose: To calculate the output factor of irregular shape electron beam at extended SSD using modified lateral buildupratio method. Methods: Circular cutouts from 2.0cm diameter to maximum possible sizes were prepared for applicator cone size of 15×15cm. In addition, different irregular cutouts were prepared. Percentage depth dose (PDD) curves were measured for each cutout using 6, 9, 12 and 16MeV at the standard SSD of 100cm. The scanning was done using Multidata system and Scanditronix diodes on 2100SC Varian LINAC. In addition, for each cutout and electron beam energy doses were measured at SSD values of 100, 105, 110, 115cm using EDR2 films and diodes. Results: The measured PDD were normalized to the depth of 1.0mm. The lateral buildupratio (LBR) and the lateral scatter parameter (sigma) were calculated for each circular cutout using the open 15X15cm2 field as the reference field. Taking the linear increase of sigma with cutout size into account, PDD of the irregular cutouts were calculated at 100 cm SSD. Furthermore, using the dose measured at different SSDs, the effective SSD value for each circular cutout and electron beam energy was determined. Employing the LBR and the effectiveSSD values of the circular cutouts along with the calculatedmore »
 Authors:
 South Carolina Oncology Associates, Columbia, SC (United States)
 Publication Date:
 OSTI Identifier:
 22369717
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Medical Physics; Journal Volume: 41; Journal Issue: 6; Other Information: (c) 2014 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 07 ISOTOPES AND RADIATION SOURCES; 60 APPLIED LIFE SCIENCES; CALIBRATION; CALIBRATION STANDARDS; DEPTH DOSE DISTRIBUTIONS; ELECTRON BEAMS; LINEAR ACCELERATORS; RADIATION DOSES
Citation Formats
Alkhatib, H, and Gebreamlak, W. SUET601: Output Factor Calculation of Irregular Shape Electron Cutout at Extended SSD. United States: N. p., 2014.
Web. doi:10.1118/1.4888937.
Alkhatib, H, & Gebreamlak, W. SUET601: Output Factor Calculation of Irregular Shape Electron Cutout at Extended SSD. United States. doi:10.1118/1.4888937.
Alkhatib, H, and Gebreamlak, W. 2014.
"SUET601: Output Factor Calculation of Irregular Shape Electron Cutout at Extended SSD". United States.
doi:10.1118/1.4888937.
@article{osti_22369717,
title = {SUET601: Output Factor Calculation of Irregular Shape Electron Cutout at Extended SSD},
author = {Alkhatib, H and Gebreamlak, W},
abstractNote = {Purpose: To calculate the output factor of irregular shape electron beam at extended SSD using modified lateral buildupratio method. Methods: Circular cutouts from 2.0cm diameter to maximum possible sizes were prepared for applicator cone size of 15×15cm. In addition, different irregular cutouts were prepared. Percentage depth dose (PDD) curves were measured for each cutout using 6, 9, 12 and 16MeV at the standard SSD of 100cm. The scanning was done using Multidata system and Scanditronix diodes on 2100SC Varian LINAC. In addition, for each cutout and electron beam energy doses were measured at SSD values of 100, 105, 110, 115cm using EDR2 films and diodes. Results: The measured PDD were normalized to the depth of 1.0mm. The lateral buildupratio (LBR) and the lateral scatter parameter (sigma) were calculated for each circular cutout using the open 15X15cm2 field as the reference field. Taking the linear increase of sigma with cutout size into account, PDD of the irregular cutouts were calculated at 100 cm SSD. Furthermore, using the dose measured at different SSDs, the effective SSD value for each circular cutout and electron beam energy was determined. Employing the LBR and the effectiveSSD values of the circular cutouts along with the calculated PDD of the irregular cutouts, the output factors of the irregular cutout at different extended SSD values were calculated. Finally, the calculated output factors were compared with the measured values. Conclusion: In this research, it is shown that output factor of irregular shape electron beam at extended SSD can be determined by using the LBR and the effective SSD values of circular cutouts. The percentage difference of the calculated output factor from the measured output factor for irregular cutouts at extended SSD were within 3.0%.},
doi = {10.1118/1.4888937},
journal = {Medical Physics},
number = 6,
volume = 41,
place = {United States},
year = 2014,
month = 6
}

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