Calibration curves obtained exposing Gafchromic EBT films to 6 and 15 MV photon beams at different doses.
Comparison between the raw data EBT profile (179 cGy irradiation corresponding to index ) and the unflatness-corrected one, together with the second order polynomial fit and the unflatness correction factors used.
Normalized values, calculated by a second order polynomial fit of PV profiles, for different uniform dose irradiation, after correction for irradiation field flatness ( indicates central pixel value of profiles).
Dose profile for 45° physical wedge measured by an EBT strip and by the ionization chamber.
Dose profiles of 30° VW produced by the 6 MV Oncor photon beam in high dose rate and in low dose rate modality.
Dose profiles for 15°, 30°, 45°, and 60° VW, (a) 6 and (b) 15 MV photon beam, calculated by OTP and measured with EBT films.
Mechanical limits of Siemens Oncor LINAC as regards jaw translation speed and monitor unit rate in the two modalities (high and low dose rate) (Ref. 1).
Deviation definitions in different profile regions and confidence limits proposed by the ESTRO Booklet No. 7 (Ref. 12) for complex geometry fields. For the out of field area, deviations have to be calculated normalizing to the dose value at the central axis.
Confidence limits calculated (first row) to validate EBT correction and calibration method comparing a physical wedge profile measured with EBT and with ionization chamber (0.147 cc) and (second row) to verify Oncor delivery invariance, comparing the same VW field delivered in the two dose rate modalities and measured with EBT strips.
Wedge factors measured and planned for Siemens Oncor 6 MV photon beam.
Confidence limits calculated comparing Virtual Wedge beam profiles measured with EBT films and calculated by OTP Enhanced algorithm.
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