Evidence map›Paper›PMID 41987335›Full record

ArticleJournal of applied clinical medical physics2026

Credentialing of small-field dosimetry for the lung SBRT in Japan Clinical Oncology Group clinical trial.

Daisuke Kawahara, Shuichi Ozawa, Toshiyuki Minemura, Yu Kumazaki, Hideaki Hirashima, Satoshi Kito, Hiroyuki Okamoto, Mitsuhiro Nakamura, Teiji Nishio, Ikuno Nishibuchi and 6 more

Abstract read
In one paragraph

Article in Journal of applied clinical medical 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

16 authors.

Daisuke KawaharaDepartment of Radiation Oncology, Graduate school of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Shuichi OzawaDepartment of Radiation Oncology, Graduate school of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.ORCID https://orcid.org/0000-0001-5459-9846
Toshiyuki MinemuraSection of Radiation Safety and Quality Assurance, National Cancer Center Hospital, Tokyo, Japan.
Yu KumazakiDepartment of Radiation Oncology, International Medical Center, Saitama Medical University, Saitama, Japan.
Hideaki HirashimaDepartment of Radiation Oncology and Image-Applied Therapy, Kyoto University, Shogoin, Sakyo-ku, Kyoto, Japan.ORCID https://orcid.org/0000-0003-1548-1970
Satoshi KitoDepartment of Radiation Oncology, Department of Radiology, Tokyo Metropolitan Cancer and Infectious Disease Center Komagome Hospital, Tokyo, Japan.
Hiroyuki OkamotoRadiation Safety and Quality Assurance Division, National Cancer Center Hospital, Tokyo, Japan.ORCID https://orcid.org/0000-0001-9491-787X
Mitsuhiro NakamuraDepartment of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, Kyoto, Japan.ORCID https://orcid.org/0000-0002-6406-2097
Teiji NishioMedical Physics Laboratory, Division of Health Science, Graduate School of Medicine, The University of Osaka, Osaka, Japan.
Ikuno NishibuchiDepartment of Radiation Oncology, Graduate school of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Yukinori MatsuoDepartment of Radiation Oncology, Kindai University Faculty of Medicine, 377-2, Ohno-Higashi, Osaka-Sayama, Osaka, Japan.ORCID https://orcid.org/0000-0002-4372-8259
Tomoki KimuraDepartment of Radiation Oncology, Kochi Medical School, Kochi University, Oko-cho, Nangoku-shi, KohasuKochi, Japan.
Satoshi IshikuraDepartment of Radiation Oncology, St. Luke's International Hospital, St. Luke's International University, Chuo-ku, Tokyo, Japan.
Naoto ShikamaDepartment of Radiation Oncology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
Yasushi NagataDepartment of Radiation Oncology, Chugoku Rosai Hospital, Emeritus Professor, Hiroshima University, Kure, Japan.
Takashi MizowakiDepartment of Radiation Oncology and Image-Applied Therapy, Kyoto University, Shogoin, Sakyo-ku, Kyoto, Japan.ORCID https://orcid.org/0000-0002-8135-8746

Funding

Japan Agency for Medical Research and Development JP23ck0106830Japan Society for the Promotion of Science JP19K12865Japan Society for the Promotion of Science JP24K15811
6 · The paper itself

Abstract

backgroundSmall-field dosimetry plays a pivotal role in stereotactic body radiation therapy (SBRT), where high-precision dose delivery is essential. In multi-institutional clinical trials, quality assurance (QA) becomes increasingly critical due to the variability in linear accelerator (linac) output calibration and treatment planning system (RTPS) configurations. Conventional relative dose factor, which assess relative dose outputs, lack absolute dose information and thus cannot verify the consistency of linac calibration or monitor unit (MU)-to-dose conversion across institutions. These limitations may compromise treatment quality and undermine the integrity of clinical trials. Therefore, an enhanced QA method that incorporates absolute dosimetry is required. PURPOSE: This study introduces and implements a novel credentialing procedure for small-field dosimetry in SBRT clinical trials using the absorbed dose per MU, expressed in cGy/MU. By integrating absolute dose information into the verification process, this method aims to evaluate both linac output calibration and small-field modeling accuracy across institutions.

methodsA nationwide dosimetric survey was conducted involving 545 beams from 120 institutions participating in Japan Clinical Oncology Group (JCOG) trials. Treatment plans were created in each institution's RTPS by prescribing 10 Gy to the isocenter for square field sizes of 2 × 2 to 10 × 10 cm

resultsOf the 545 beams analyzed, 97.8% met the ±3% tolerance criteria. Discrepancies in the ten beams were attributed to small-field beam modeling errors or incorrect RTPS MU-to-dose settings, which were subsequently corrected through feedback. Although variations were observed between the dose calculation algorithms and RTPSs, the differences were within 0.6%, 0.4%, and 1.6%, respectively. The credentialing process proved robust in standardizing dose calculations for clinical trial participation.

conclusionThe proposed absorbed dose per MU-based method enables comprehensive small-field dosimetry evaluation by incorporating absolute dose verification into the credentialing process. This approach effectively identifies calibration inconsistencies that are not detectable using traditional relative dose factor methods. Its application across a large cohort of institutions demonstrated high accuracy and inter-institutional consistency, reinforcing its utility as a practical QA tool in SBRT clinical trials. By enhancing standardization in RTPS performance and linac output verification, this method strengthens the foundation of safe and reliable SBRT implementation in multi-center clinical research.

Indexed as

Clinical Trials as TopicCredentialingLung NeoplasmsParticle AcceleratorsQuality Assurance, Health CareRadiometryRadiosurgeryRadiotherapy Planning, Computer-AssistedCalibrationHumansJapanRadiotherapy DosageRadiotherapy, Intensity-Modulatedcredentialing procedure for clinical trialsmall field dosimetrystereotactic body radiation therapy

Identifiers

PMID41987335
PMCPMC13083588

What OpenQuestion holds

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Registered trials

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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.