% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@ARTICLE{Rank:284803,
author = {L. Rank and O. Dogan and B. Kopp and S. Mein$^*$ and G.
Verona-Rinati and R. Kranzer and M. Marinelli and A.
Mairani$^*$ and T. Tessonnier$^*$},
title = {{D}evelopment and benchmarking of a dose rate engine for
raster-scanned {FLASH} helium ions.},
journal = {Medical physics},
volume = {51},
number = {3},
issn = {0094-2405},
address = {College Park, Md.},
publisher = {AAPM},
reportid = {DKFZ-2023-02106},
pages = {2251-2262},
year = {2024},
note = {#LA:E210# / 2024 Mar;51(3):2251-2262},
abstract = {Radiotherapy with charged particles at high dose and
ultra-high dose rate (uHDR) is a promising technique to
further increase the therapeutic index of patient
treatments. Dose rate is a key quantity to predict the
so-called FLASH effect at uHDR settings. However, recent
works introduced varying calculation models to report dose
rate, which is susceptible to the delivery method, scanning
path (in active beam delivery) and beam intensity.This work
introduces an analytical dose rate calculation engine for
raster scanned charged particle beams that is able to
predict dose rate from the irradiation plan and recorded
beam intensity. The importance of standardized dose rate
calculation methods is explored here.Dose is obtained with
an analytical pencil beam algorithm, using pre-calculated
databases for integrated depth dose distributions and
lateral penumbra. Dose rate is then calculated by combining
dose information with the respective particle fluence (i.e.,
time information) using three dose-rate-calculation models
(mean, instantaneous, and threshold-based). Dose rate
predictions for all three models are compared to uHDR helium
ion beam (145.7 MeV/u, range in water of approximatively
14.6 cm) measurements performed at the Heidelberg Ion Beam
Therapy Center (HIT) with a diamond-detector prototype.
Three scanning patterns (scanned or snake-like) and four
field sizes are used to investigate the dose rate
differences.Dose rate measurements were in good agreement
with in-silico generated distributions using the here
introduced engine. Relative differences in dose rate were
below $10\%$ for varying depths in water, from 2.3 to 14.8
cm, as well as laterally in a near Bragg peak area. In the
entrance channel of the helium ion beam, dose rates were
predicted within $7\%$ on average for varying irradiated
field sizes and scanning patterns. Large differences in
absolute dose rate values were observed for varying
calculation methods. For raster-scanned irradiations, the
deviation between mean and threshold-based dose rate at the
investigated point was found to increase with the field size
up to $63\%$ for a 10 mm × 10 mm field, while no
significant differences were observed for snake-like
scanning paths.This work introduces the first dose rate
calculation engine benchmarked to instantaneous dose rate,
enabling dose rate predictions for physical and biophysical
experiments. Dose rate is greatly affected by varying
particle fluence, scanning path, and calculation method,
highlighting the need for a consensus among the FLASH
community on how to calculate and report dose rate in the
future. The here introduced engine could help provide the
necessary details for the analysis of the sparing effect and
uHDR conditions.},
keywords = {engine (Other) / flash (Other) / helium ions (Other) /
radiotherapy (Other) / ultra high dose rate (Other)},
cin = {E210 / HD01},
ddc = {610},
cid = {I:(DE-He78)E210-20160331 / I:(DE-He78)HD01-20160331},
pnm = {315 - Bildgebung und Radioonkologie (POF4-315)},
pid = {G:(DE-HGF)POF4-315},
typ = {PUB:(DE-HGF)16},
pubmed = {pmid:37847027},
doi = {10.1002/mp.16793},
url = {https://inrepo02.dkfz.de/record/284803},
}