<abstract xmlns="http://www.w3.org/1999/xhtml">

<sec id="j_raon-2022-0048_s_007">
<h3>Background</h3>
<p>The aim of the study was to evaluate the accuracy of volumetric lung image guidance using the spine or carina as a surrogate to target for image registration, as the best approach is not established.</p>
</sec>
<sec id="j_raon-2022-0048_s_008">
<h3>Patients and methods</h3>
<p>Cone beam computed tomography images from the 1<sup>st</sup>, 10<sup>th</sup>, 15<sup>th</sup>, and 20<sup>th</sup> fraction in 40 lung cancer patients treated with radical radiotherapy were retrospectively registered to planning CT, using three approaches. The spine and carina alignment set-up deviations from a reference (tumour/lymph nodes) registration in the lateral (LAT), longitudinal (LONG) and vertical (VRT) directions were analysed and compared. Tumour location and nodal stage influence on registration accuracy were explored.</p>
</sec>
<sec id="j_raon-2022-0048_s_009">
<h3>Results</h3>
<p>The spine and carina mean set-up deviation from reference were largest in the LONG, with the best match in the VRT and LAT, respectively. Both strategies were more accurate in central tumours, with the carina being more precise in 50% LAT and 66% LONG mean deviations. For all measurements in all patients a carina <italic>vs</italic>. spine registration comparison showed improved carina accuracy in LAT and LONG. In comparative subgroup analysis the carina was superior compared to spine in LAT and LONG in centrally located tumours, N2 and N3. Both strategies were comparable for peripheral tumours and N0.</p>
</sec>
<sec id="j_raon-2022-0048_s_010">
<h3>Conclusions</h3>
<p>Carina registration shows greater accuracy compared to spine in the LAT and LONG directions and is superior in central tumours, N2 and N3. The spine and carina surrogates are equally accurate for peripheral tumours and N0. We propose the carina as a surrogate to target for CBCT image registration in locally advanced lung cancer.</p>
</sec>
</abstract>

Background
The aim of the study was to evaluate the accuracy of volumetric lung image guidance using the spine or carina as a surrogate to target for image registration, as the best approach is not established.


Patients and methods
Cone beam computed tomography images from the 1st, 10th, 15th, and 20th fraction in 40 lung cancer patients treated with radical radiotherapy were retrospectively registered to planning CT, using three approaches. The spine and carina alignment set-up deviations from a reference (tumour/lymph nodes) registration in the lateral (LAT), longitudinal (LONG) and vertical (VRT) directions were analysed and compared. Tumour location and nodal stage influence on registration accuracy were explored.


Results
The spine and carina mean set-up deviation from reference were largest in the LONG, with the best match in the VRT and LAT, respectively. Both strategies were more accurate in central tumours, with the carina being more precise in 50% LAT and 66% LONG mean deviations. For all measurements in all patients a carina vs. spine registration comparison showed improved carina accuracy in LAT and LONG. In comparative subgroup analysis the carina was superior compared to spine in LAT and LONG in centrally located tumours, N2 and N3. Both strategies were comparable for peripheral tumours and N0.


Conclusions
Carina registration shows greater accuracy compared to spine in the LAT and LONG directions and is superior in central tumours, N2 and N3. The spine and carina surrogates are equally accurate for peripheral tumours and N0. We propose the carina as a surrogate to target for CBCT image registration in locally advanced lung cancer.

The spine and carina as a surrogate for target registration in cone-beam CT imaging verification in locally advanced lung cancer radiotherapy

Radiology and Oncology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Background
The aim of the study was to evaluate the accuracy of volumetric lung image guidance using the spine or carina as a surrogate to target for image...

The spine and carina as a surrogate for target registration in cone-beam CT imaging verification in locally advanced lung cancer radiotherapy

Article Category: Research Article

Published Online: Mar 22, 2023

Page range: 86 - 94

Received: May 08, 2022

Accepted: Oct 19, 2022

DOI: https://doi.org/10.2478/raon-2022-0048

© 2023 Jasna But-Hadzic, Karmen Strljic, Valerija Zager Marcius, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.