Evidence map›Paper›PMID 38043086›Full record

ArticleMedical physics2024

2D antiscatter grid and scatter sampling based CBCT method for online dose calculations during CBCT guided radiation therapy of pelvis.

Farhang Bayat, Brian Miller, Yeonok Park, Zhelin Yu, Timur Alexeev, David Thomas, Kelly Stuhr, Brian Kavanagh, Moyed Miften, Cem Altunbas

Abstract read
In one paragraph

Article in Medical physics, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

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4citing papers in PubMed
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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

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4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

10 authors.

Farhang BayatDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado, USA.
Brian MillerDepartment of Radiation Oncology, The University of Arizona, College of Medicine, Tucson, Arizona, USA.
Yeonok ParkDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado, USA.
Zhelin YuDepartment of Computer Science and Engineering, University of Colorado Denver, Denver, Colorado, USA.
Timur AlexeevDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado, USA.
David ThomasDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado, USA.
Kelly StuhrDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado, USA.
Brian KavanaghDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado, USA.
Moyed MiftenDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado, USA.
Cem AltunbasDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado, USA.

Funding

Improving quantitative accuracy and tissue visualization in CBCT guided radiation therapyR01CA245270 · NCI · UNIVERSITY OF COLORADO DENVER · PI ALTUNBAS, CEM · 2020 to 2025
$2.1M
A dedicated two dimensional antiscatter grid for CBCT in radiation therapyR21CA198462 · NCI · UNIVERSITY OF COLORADO DENVER · PI ALTUNBAS, CEM · 2016 to 2017
$372k
NCI NIH HHS R01 CA245270NCI NIH HHS R21 CA198462
6 · The paper itself

Abstract

backgroundOnline dose calculations before the delivery of radiation treatments have applications in dose delivery verification, online adaptation of treatment plans, and simulation-free treatment planning. While dose calculations by directly utilizing CBCT images are desired, dosimetric accuracy can be compromised due to relatively lower HU accuracy in CBCT images. PURPOSE: In this work, we propose a novel CBCT imaging pipeline to enhance the accuracy of CBCT-based dose calculations in the pelvis region. Our approach aims to improve the HU accuracy in CBCT images, thereby improving the overall accuracy of CBCT-based dose calculations prior to radiation treatment delivery.

methodsAn in-house developed quantitative CBCT pipeline was implemented to address the CBCT raw data contamination problem. The pipeline combines algorithmic data correction strategies and 2D antiscatter grid-based scatter rejection to achieve high CT number accuracy. To evaluate the effect of the quantitative CBCT pipeline on CBCT-based dose calculations, phantoms mimicking pelvis anatomy were scanned using a linac-mounted CBCT system, and a gold standard multidetector CT used for treatment planning (pCT). A total of 20 intensity-modulated treatment plans were generated for five targets, using 6 and 10 MV flattening filter-free beams, and utilizing small and large pelvis phantom images. For each treatment plan, four different dose calculations were performed using pCT images and three CBCT imaging configurations: quantitative CBCT, clinical CBCT protocol, and a high-performance 1D antiscatter grid (1D ASG). Subsequently, dosimetric accuracy was evaluated for both targets and organs at risk as a function of patient size, target location, beam energy, and CBCT imaging configuration.

resultsWhen compared to the gold-standard pCT, dosimetric errors in quantitative CBCT-based dose calculations were not significant across all phantom sizes, beam energies, and treatment sites. The largest error observed was 0.6% among all dose volume histogram metrics and evaluated dose calculations. In contrast, dosimetric errors reached up to 7% and 97% in clinical CBCT and high-performance ASG CBCT-based treatment plans, respectively. The largest dosimetric errors were observed in bony targets in the large phantom treated with 6 MV beams. The trends of dosimetric errors in organs at risk were similar to those observed in the targets.

conclusionsThe proposed quantitative CBCT pipeline has the potential to provide comparable dose calculation accuracy to the gold-standard planning CT in photon radiation therapy for the abdomen and pelvis. These robust dose calculations could eliminate the need for density overrides in CBCT images and enable direct utilization of CBCT images for dose delivery monitoring or online treatment plan adaptations before the delivery of radiation treatments.

Indexed as

Spiral Cone-Beam Computed TomographyAbdomenCone-Beam Computed TomographyHumansPelvisPhantoms, ImagingRadiotherapy DosageRadiotherapy Planning, Computer-Assistedaccurate radiation treatment dose calculationsadaptive therapycone beam CT

Identifiers

PMID38043086
PMCPMC11008043

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.