Browse by author
Lookup NU author(s): Neil Richmond, Dr Liam Walker
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
© 2026 American Association of Medical Dosimetrists. In our department, monitor units (MU) for electron treatments are calculated using a Monte Carlo algorithm in the RayStation treatment planning system and independently checked using RadCalc software. An audit found that 22 of 50 independent checks failed the ± 5% local tolerance level. One of the causes for the discrepancy was thought to be that the RadCalc calculation takes no account of the patient surface curvature. Three-dimensional printed moulds were used to create wax “domes” and “bowls” with curvatures ranging from +0.33 cm−1 to −0.13 cm−1. The dose per MU delivered at dmax, under the wax phantoms, to a calibrated NACP type chamber was determined by measurement. The fields were delivered using 6 to 18 MeV electrons from a Varian TrueBeam linac. The measured data shows that the dose varies linearly, for a given electron energy, with the curvature of the wax mould. This information was used to create a set of curvature correction factors to be applied to the 50 independent MU checks. When the appropriate correction factor was applied to the RadCalc MU only 3 of the 50 calculations were beyond the tolerance level, improving agreement and reducing the number of out of tolerance results.
Author(s): Richmond N, Chester K, Walker L
Publication type: Article
Publication status: Published
Journal: Medical Dosimetry
Year: 2026
Pages: Epub ahead of print
Online publication date: 22/04/2026
Acceptance date: 15/03/2026
ISSN (print): 0958-3947
ISSN (electronic): 1873-4022
Publisher: Elsevier Inc.
URL: https://doi.org/10.1016/j.meddos.2026.03.007
DOI: 10.1016/j.meddos.2026.03.007
Altmetrics provided by Altmetric
