Open AccessSurface and build‐up dose comparison between Elekta 6 MV flattening filter and flattening‐filter‐free beams using an advanced Markus ionization chamber and a solid water‐equivalent phantom
Author(s) -
Imae Toshikazu,
Takenaka Shigeharu,
Watanabe Yuichi,
Aoki Atsushi,
Matsuda Kanako,
Sasaki Katsutake,
Saegusa Shigeki,
Nawa Kanabu,
Nakagawa Keiichi,
Abe Osamu
Publication year - 2020
Publication title -
journal of applied clinical medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.83
H-Index - 48
ISSN - 1526-9914
DOI - 10.1002/acm2.13094
Subject(s) - imaging phantom , ionization chamber , linear particle accelerator , flattening , percentage depth dose curve , field size , materials science , water equivalent , nuclear medicine , optics , physics , ionization , beam (structure) , medicine , ion , quantum mechanics , meteorology , snow , composite material
Using a plane‐parallel advanced Markus ionization chamber and a stack of water‐equivalent solid phantom blocks, percentage surface and build‐up doses of Elekta 6 MV flattening filter (FF) and flattening‐filter‐free (FFF) beams were measured as a function of the phantom depth for field sizes ranging from 2 × 2 to 10 × 10 cm 2 . It was found that the dose difference between the FF and the FFF beams was relatively small. The maximum dose difference between the FF and the FFF beams was 4.4% at a depth of 1 mm for a field size of 2 × 2 cm 2 . The dose difference was gradually decreased while the field size was increased up to 10 × 10 cm 2 . The measured data were also compared to published Varian FF and FFF data, suggesting that the percentage surface and build‐up doses as well as the percentage dose difference between FF and FFF beams by our Elekta linac were smaller than those by the Varian linac.