Assessment of four dose calculation algorithms using IAEA-TECDOC-1583 with medium dependency correction factor (K_med) application

<h3>Purpose</h3><p dir="ltr">This study discusses the measurement of dose in clinical commissioning tests described in IAEA-TECDOC-1583. It explores the application of Monte Carlo (MC) modelled medium dependency correction factors (K_med) for accurate dose measurement in bone and lung materials using the CIRS phantom. </p><h3>Methods</h3><p dir="ltr">BEAMnrc codes simulate radiation sources and model radiation transport for 6 MV and 15 MV photon beams. CT images of the CIRS phantom are converted to an MC compatible phantom. The PTW 30013 farmer chamber measures doses within modeled CIRS phantom. K_med are determined by averaging values from four central voxels within the sensitive volume of the farmer chamber. K_med is calculated for D_m.m and D_w.walgorithm types in bone and lung media for both photon beams. </p><h3>Results</h3><p dir="ltr">Average modelled correction factors for D_m.mcalculations using the farmer chamber are 0.976 (±0.1 %) for 6 MV and 0.979 (±0.1 %) for 15 MV in bone media. Correspondingly, correction factors for Dw.w calculations are 0.99 (±0.3 %) and 0.992 (±0.4 %), respectively. For lung media, average correction factors for D_m.m calculations are 1.02 (±0.3 %) for 6 MV and 1.022 (±0.4 %) for 15 MV. Correspondingly, correction factors for D_w.wcalculations are 1.01 (±0.3 %) and 1.012 (±0.2 %), respectively. </p><h3>Conclusions</h3><p dir="ltr">This study highlights the significant impact of applying K_med on dose differences between measurement and calculation during the dose audit process.</p><h2>Other Information</h2><p dir="ltr">Published in: Physica Medica<br>License: <a href="http://creativecommons.org/licenses/by/4.0/" target="_blank">http://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.1016/j.ejmp.2024.103390" target="_blank">https://dx.doi.org/10.1016/j.ejmp.2024.103390</a></p>