Evidence map›Paper›PMID 40699513›Full record

ArticlePhysical and engineering sciences in medicine2025

Impact of differences in computed tomography value-electron density/physical density conversion tables on calculate dose in low-density areas.

Mia Nomura, Shunsuke Goto, Mizuki Yoshioka, Yuiko Kato, Ayaka Tsunoda, Kunio Nishioka, Yoshinori Tanabe

Abstract read
In one paragraph

Article in Physical and engineering sciences in medicine, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing 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

2 citing papers in PubMed.

  1. Article
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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

7 authors.

Mia NomuraFaculty of Health Sciences, Department of Radiological Technology, Okayama University Medical School, Okayama University, 2-5-1 Shikata, Kita-ku, Okayama, 700-8558, Japan.
Shunsuke GotoGraduate School of Health Sciences, Department of Radiological Technology, Okayama University, 2-5-1, Shikata, Kita, Okayama, 700-8525, Japan.
Mizuki YoshiokaFaculty of Health Sciences, Department of Radiological Technology, Okayama University Medical School, Okayama University, 2-5-1 Shikata, Kita-ku, Okayama, 700-8558, Japan.
Yuiko KatoFaculty of Health Sciences, Department of Radiological Technology, Okayama University Medical School, Okayama University, 2-5-1 Shikata, Kita-ku, Okayama, 700-8558, Japan.
Ayaka TsunodaFaculty of Health Sciences, Department of Radiological Technology, Okayama University Medical School, Okayama University, 2-5-1 Shikata, Kita-ku, Okayama, 700-8558, Japan.
Kunio NishiokaDepartment of Radiology, Tokuyama Central Hospital, 1-1 Kodacho, Shunan, Yamaguchi, 745-8522, Japan.
Yoshinori TanabeFaculty of Medicine, Graduate School of Health Sciences, Okayama University, 2-5-1, Shikata, Kita, Okayama, 700-8525, Japan. tanabey@okayama-u.ac.jp.ORCID http://orcid.org/0000-0001-7259-3317

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

In radiotherapy treatment planning, the extrapolation of computed tomography (CT) values for low-density areas without known materials may differ between CT scanners, resulting in different calculated doses. We evaluated the differences in the percentage depth dose (PDD) calculated using eight CT scanners. Heterogeneous virtual phantoms were created using LN-300 lung and - 900 HU. For the two types of virtual phantoms, the PDD on the central axis was calculated using five energies, two irradiation field sizes, and two calculation algorithms (the anisotropic analytical algorithm and Acuros XB). For the LN-300 lung, the maximum CT value difference between the eight CT scanners was 51 HU for an electron density (ED) of 0.29 and 8.8 HU for an extrapolated ED of 0.05. The LN-300 lung CT values showed little variation in the CT-ED/physical density data among CT scanners. The difference in the point depth for the PDD in the LN-300 lung between the CT scanners was < 0.5% for all energies and calculation algorithms. Using Acuros XB, the PDD at - 900 HU had a maximum difference between facilities of > 5%, and the dose difference corresponding to an LN-300 lung CT value difference of > 20 HU was > 1% at a field size of 2 × 2 cm

Indexed as

Radiotherapy Planning, Computer-AssistedAlgorithmsElectronsHumansLungPhantoms, ImagingTomography, X-Ray ComputedComputed tomographyDose calculationInter-facility variationLow-density regionsPercentage depth doseRadiation therapy planning system

Identifiers

PMID40699513
PMCPMC12738602

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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.