TY  - JOUR
IS  - 1
ID  - discovery10106521
JF  - BJR|Open
AV  - public
N2  - Objective: The reconstruction kernel used for a CT scan
strongly influences the image quality. This work investigates the changes in Hounsfield units (HUs) which can
arise when altering the image reconstruction kernel for
planning CT images and the associated changes in dose
in the radiotherapy treatment plan if the treatment planning system (TPS) is not re-calibrated.
Methods: Head and neck, prostate and lung CT images
from four centres were used. For a specific scan, the base
image was acquired using the original reconstruction
kernel (used when the TPS was calibrated) and the treatment plan produced. The treatment plan was applied to
all images from the other reconstruction kernels. Differences in dose-volume metrics for the planning target
volume (PTV) and organs at risk (OARs) were noted and
HU differences between images measured for air, soft
tissue and bone.
Results:  HU change in soft tissue had the greatest influence on dose change. When within ą20 HU for soft tissue
and ą50 HU for bone and air the dose change in the PTV
and OAR was within ą0.5% and ą1% respectively.
Conclusions:  When imaging parameters were changed,
if HU change was within ą20 HU for soft tissue and ą50
HU for bone and air, the change in the PTV and OAR
doses was below 1%.
Advances in knowledge: The degree of dose change in
the treatment plan with HU change is demonstrated for
current TPS algorithms. This adds to the limited evidence
base for recommendations on HU tolerances as a tool for
radiotherapy CT protocol optimization.
A1  - Davis, AT
A1  - Muscat, S
A1  - Palmer, AL
A1  - Buckle, D
A1  - Earley, J
A1  - Williams, MGJ
A1  - Nisbet, A
VL  - 1
UR  - https://doi.org/10.1259/bjro.20190023
Y1  - 2019/07//
TI  - Radiation dosimetry changes in radiotherapy treatment plans for adult patients arising from the selection of the CT image reconstruction kernel
PB  - British Institute of Radiology
N1  - This is an open access article distributed under the terms of the Creative Commons
Attribution 4.0 International License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source
are credited. https://creativecommons.org/licenses/by/4.0/
ER  -