SU-E-T-206: Comparison of EBT and EBT3 RadioChromic Films in Radiation Field of Parotid Cancer Radiotherapy

Journal Article · Mon Jun 15 04:00:00 EDT 2015 · Medical Physics

DOI:https://doi.org/10.1118/1.4924567· OSTI ID:22545326

Toosi, T Bahreyni; Mianaei, F Khorshidi; Ghorbani, M; Khabbaz Kazemi, N Mohammadian; Mohammadi, M ^[1]; Meigooni, A Soleimani ^[2]

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1. Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of)
2. Comprehensive Cancer Center of Nevada, Las Vegas, NV (United States)

Purpose: The aim of the current study is to compare EBT and EBT3 RadioChromic films in dosimetry of radiotherapy fields for treatment of parotid cancer. Methods: The calibrations of EBT and EBT3 films were performed with the same setups for doses ranging from 0.2 Gy to 5 Gy using 6 MV photon beam of a Siemens Primus linac. These films were scanned in color mode (RGB) by a Microtek (1000XL) scanner and the red color channel data was extracted. Treatment planning for parotid cancer radiation therapy was performed on a RANDO phantom. Skin dose was measured at different points in the right anterior oblique (RAO) and right posterior oblique (RPO) fields by EBT and EBT3 films. Results: Dosimetry was performed with the same conditions for the two film types for calibration and in-phantom in parotid cancer radiotherapy. The measured net optical density (NOD) in EBT film was in some extent higher than that from EBT3 film. The minimum difference between these two films under calibration conditions was about 2.9% (for 0.2 Gy). However, the maximum difference was 35.5% (for 0.5 Gy). In the therapeutic fields of parotid cancer radiotherapy at different points, the measured dose from EBT film was higher than the EBT3 film. In these fields the minimum and maximum measured dose differences were 16.0% and 25.5%, respectively. Conclusion: With the same irradiation and reading conditions, EBT film demonstrates higher NOD than the EBT3 film. This effect may be related to the higher sensitivity of EBT film over EBT3 film. However, the obtained dose differences between these two films in low dose range can be due to the differences in fitting functions applied following the calibration process.

• OSTI ID: 22545326
• Journal Information: Medical Physics, Journal Name: Medical Physics Journal Issue: 6 Vol. 42; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
61 RADIATION PROTECTION AND DOSIMETRY
CALIBRATION
FILM DOSIMETRY
IRRADIATION
LINEAR ACCELERATORS
NEOPLASMS
PHOTOGRAPHIC FILM DOSEMETERS
PHOTON BEAMS
RADIOTHERAPY
SKIN