Evidence map›Paper›PMID 42612829›Full record

ArticleInternational journal of radiation oncology, biology, physics2026

Improvement of Soft Tissue Contrast and CT Number Accuracy in Proton Therapy CBCT With Hardware-based Scatter Suppression: Results From a Prospective Trial.

Uttam Pyakurel, Yawei Zhang, Ryan Sabounchi, Farhang Bayat, Junxiao Hu, Sébastien Brousmiche, Curtis Bryant, Nancy Mendenhall, Perry Johnson, Cem Altunbas

Abstract read
In one paragraph

Article in International journal of radiation oncology, biology, physics, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors.

Uttam PyakurelDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado.
Yawei ZhangUniversity of Florida Health Proton Therapy Institute, Jacksonville, Florida.
Ryan SabounchiDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado.
Farhang BayatDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado.
Junxiao HuBiostatistics Core, University of Colorado Cancer Center, Aurora, Colorado; Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado.
Sébastien BrousmicheIon Beam Applications, Louvain-la-Neuve, Belgium.
Curtis BryantUniversity of Florida Health Proton Therapy Institute, Jacksonville, Florida.
Nancy MendenhallUniversity of Florida Health Proton Therapy Institute, Jacksonville, Florida.
Perry JohnsonUniversity of Florida Health Proton Therapy Institute, Jacksonville, Florida.
Cem AltunbasDepartment of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado. Electronic address: cem.altunbas@cuanschutz.edu.

Funding

University of Colorado Cancer Center Support Grant - Lung Cancer Patient-Derived Xenografts with Autologous Human Immune SystemsP30CA046934 · NCI · UNIVERSITY OF COLORADO DENVER · PI James V Degregori · 1988 to 2026
$117.0M
Improving quantitative accuracy and tissue visualization in CBCT guided radiation therapyR01CA245270 · NCI · UNIVERSITY OF COLORADO DENVER · PI ALTUNBAS, CEM · 2020 to 2025
$2.1M
NCI NIH HHS P30 CA046934NCI NIH HHS R01 CA245270
6 · The paper itself

Abstract

purposeAdaptive proton therapy using cone beam CT (CBCT) requires accurate CT numbers for dose calculation and sufficient soft tissue visibility for reliable target and organ delineation. However, scatter in conventional CBCT causes substantial CT number inaccuracies and poor soft tissue contrast, limiting its use in adaptive workflows. To address this, a novel 2-dimensional antiscatter grid (2D ASG) prototype and raw data correction algorithms were developed for a proton gantry-mounted CBCT system. This prospective study evaluated their impact on CBCT image quality in human subjects. METHODS AND MATERIALS: Ten patients undergoing proton therapy for prostate cancer were enrolled in an institutional review board-approved imaging study. Each participant underwent 2 CBCT scans on a gantry-mounted proton therapy CBCT system: (1) standard CBCT with software-based scatter correction and (2) CBCT with the 2D ASG. Acquisition parameters and imaging dose were identical. Quantitative image quality metrics, including CT number error and artifact amplitude relative to planning CT, adipose-soft tissue contrast, contrast-to-noise ratio, peak signal-to-noise ratio, and structural similarity index measure, were calculated. Differences between configurations were assessed using the Wilcoxon signed-rank test.

resultsCompared with scatter-corrected clinical CBCT, the 2D ASG reduced median (min-max) soft tissue CT number errors from 169 (150-185) HU to 38 (26-54) HU (P = .002), indicating reduced scatter-induced artifacts. Median soft tissue contrast increased from 62 (42-74) HU to 125 (97-144) HU (P = .002), and contrast-to-noise ratio improved from 0.99 (0.37-1.38) to 1.57 (1.28-1.75) (P = .002). Structural similarity index measure relative to the planning CT increased from 0.53 (0.38-0.67) to 0.87 (0.85-0.93) (P = .002). Similar improvements were observed for peak signal-to-noise ratio and artifact amplitude.

conclusionsThis first prospective evaluation of a prototype 2D ASG-equipped CBCT system for proton therapy demonstrated significant improvements in CT number accuracy and soft tissue visualization, supporting its potential role in adaptive proton therapy workflows.

Identifiers

PMID42612829
PMCPMC13564206

What Socratic holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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 Socratic graph.