Roos and NACP-02 ion chamber perturbations and water-air stopping-power ratios for clinical electron beams for energies from 4 to 22 MeV.

Autor: Bailey M; Radiation Dosimetry, National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW, UK., Shipley DR, Manning JW
Jazyk: angličtina
Zdroj: Physics in medicine and biology [Phys Med Biol] 2015 Feb 07; Vol. 60 (3), pp. 1087-105. Date of Electronic Publication: 2015 Jan 14.
DOI: 10.1088/0031-9155/60/3/1087
Abstrakt: Empirical fits are developed for depth-compensated wall- and cavity-replacement perturbations in the PTW Roos 34001 and IBA / Scanditronix NACP-02 parallel-plate ionisation chambers, for electron beam qualities from 4 to 22 MeV for depths up to approximately 1.1 × R₅₀,D. These are based on calculations using the Monte Carlo radiation transport code EGSnrc and its user codes with a full simulation of the linac treatment head modelled using BEAMnrc. These fits are used with calculated restricted stopping-power ratios between air and water to match measured depth-dose distributions in water from an Elekta Synergy clinical linear accelerator at the UK National Physical Laboratory. Results compare well with those from recent publications and from the IPEM 2003 electron beam radiotherapy Code of Practice.
Databáze: MEDLINE