It is advised that PDD to TMR conversion for FFF beams should be done with phantom scatter ratios appropriate to FFF beams, or the TMR should be directly measured if required.
BJR Supplement 25 depending on the SSD, depth of measurement, and field size 128.
#Bjr supplement 25 free download for free
The results found in this study indicate that the BJR Supplement 25 data should not be used for field sizes larger than 20 cm × 20 cm at depths greater than 15 cm for the 6 MV FFF beam. This Dissertation (PhD) is brought to you for free and. The disagreement between the measured and calculated TMR plots for the 6 MV FFF beam increased with depth and field size to a maximum of 1.7 % for a 40 cm × 40 cm field. BJR Supplement- 1989 Central Axis Depth Dose Data, for X Radiations of Half Value Layers from 0.01 Mm. The TMR plots calculated from PDD were within 1 % for the 10 MV and 6 MV flattened beams, for field sizes 3 cm × 3 cm to 40 cm × 40 cm inclusive, at depths measured beyond the depth of maximum dose.
The BJR Supplement 25 data was used to convert the measured PDDs to TMRs and these were compared with the directly measured TMR data. Abstract Supplement 17 of the British Journal of Radiology is a survey of central-axis depth doses for radiotherapy machines, patterned largely on BJR. PDD and TMR scans for a variety of field sizes were measured in water using a Sun Nuclear Corporation 3D SCANNER™ on a Varian TrueBeam linear accelerator in 6 MV, 10 MV and 6 MV FFF beams.
This study assessed the validity of the conversion from percentage depth dose (PDD) to tissue maximum ratio (TMR) using BJR Supplement 25 data for flattened and flattening filter free (FFF) beams.
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