Quantification of the Role of Lead Foil in Flattening Filter Free Beam Reference Dosimetry

Authors

Song Gao
Christopher Nelson
Congjun Wang
Vindu Kathriarachchi
Michael Choi
Rishik Saxena
Robin Kendall
Peter Balter

Publication Date

4-1-2023

Journal

Journal of Applied Clinical Medical Physics

Abstract

PURPOSE: To quantify the potential error in outputs for flattening filter free (FFF) beams associated with use of a lead foil in beam quality determination per the addendum protocol for TG-51, we examined differences in measurements of the beam quality conversion factor k

METHODS: Two FFF beams, a 6 MV FFF and a 10 MV FFF, were calibrated on eight Varian TrueBeams and two Elekta Versa HD linear accelerators (linacs) according to the TG-51 addendum protocol by using Farmer ionization chambers [TN 30013 (PTW) and SNC600c (Sun Nuclear)] with traceable absorbed dose-to-water calibrations. In determining k

RESULTS: Differences in %dd(10)x with lead foil and with omission of lead foil were 0.9 ± 0.2% for the 6 MV FFF beam and 0.6 ± 0.1% for the 10 MV FFF beam. Differences in k

CONCLUSION: With evaluation of the lead foil role in determination of the k

Keywords

beam quality, flattening filter free (FFF) beams, lead foil, TG‐51 addendum protocol

Comments

PMID: 36913192