Evidence map›Paper›PMID 41758275›Full record

ArticleRadiological physics and technology2026

Establishment of local diagnostic reference levels for planning CT in adult and pediatric radiotherapy patients in 18 Japanese university hospitals.

Hideki Obara, Kiyokazu Sato, Satoshi Abe, Hiroki Katayama, Takahiro Ushijima, Takuro Okumura, Yuki Yuasa, Yoshinobu Shimohigashi, Hironori Kojima, Taka-Aki Hirose and 3 more

Abstract readMulticenter Study
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Article in Radiological physics and technology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited 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

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4 · The record

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5 · Who and what money

Authors and funding

13 authors.

Hideki ObaraDepartment of Radiology, Division of Medical Technology, Hirosaki University School of Medicine and Hospital, 53, Hon-cho, Hirosaki-shi, Aomori, 036-8563, Japan. obara@hirosaki-u.ac.jp.ORCID http://orcid.org/0000-0002-2305-1121
Kiyokazu SatoDepartment of Radiology, Division of Medical Technology, Tohoku University Hospital, 1-1, Seiryo-machi, Aoba-ku, Sendai-shi, Miyagi, 980-8574, Japan.
Satoshi AbeDepartment of Radiology, Gunma University Graduate School of Medicine and Hospital, 3-39-15, Syowa-machi, Maebashi-shi, Gunma, 371-8511, Japan.
Hiroki KatayamaDepartment of Radiology, Division of Medical Technology, Kagawa University School of Medicine and Hospital, 1750-1, Kida-gun, Miki-cho, Kagawa, 761-0793, Japan.
Takahiro UshijimaDepartment of Radiology, Mie University School of Medicine and Hospital, 2-174, Edobashi, Tsu-shi, Mie, 514-8507, Japan.
Takuro OkumuraDivision of Radiation Therapy, Department of Clinical Practice and Support, Hiroshima University Hospital, 1-2-3, Kasumi, Minami-ku, Hiroshima-shi, Hiroshima, 734-8551, Japan.
Yuki YuasaDepartment of Radiological Technology, Yamaguchi University Hospital, 1-1-1, Minamikogushi, Ube-shi, Yamaguchi, 755-8505, Japan.
Yoshinobu ShimohigashiDepartment of Radiology, Division of Medical Technology, Kumamoto University Hospital, 1-1-1, Honjo, Chuo-ku, Kumamoto-shi, Kumamoto, 860-8556, Japan.
Hironori KojimaDepartment of Radiology, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, 920-8641, Ishikawa, Japan.
Taka-Aki HiroseDepartment of Radiology, Division of Medical Technology, Kyusyu University Hospital, 3-1-1, Maidashi, Higashi-ku, Fukuoka-shi, Hakata, 812-8582, Japan.
Mizuho SaitoDepartment of Radiology, Division of Medical Technology, Hirosaki University School of Medicine and Hospital, 53, Hon-cho, Hirosaki-shi, Aomori, 036-8563, Japan.
Takashi IimoriDepartment of Radiology, Chiba University Hospital, 1-8-1, Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8677, Japan.
Masanobu TeruiCentral Radiology Division, Akita University Hospital, 44-2, Hasunuma, Hiroomote-aza, Akita-shi, Akita, 010-8543, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Planning computed tomography (CT) for radiotherapy is essential for accurate treatment delivery but also contributes to patient radiation exposure. Therefore, diagnostic reference levels (DRLs) are recommended to optimize imaging doses. However, national DRLs (NDRLs) for planning CT in Japan have only recently been introduced. The aim of this study was to establish local diagnostic reference levels (LDRLs) for planning CT scans at 18 Japanese university hospitals for both adult and pediatric anatomical patients. Data were retrospectively collected from 2008 to 2022 for six adult anatomical regions and three pediatric regions. CT dose indices (volume CT dose index [CTDIvol] and dose length product [DLP]) were analyzed, and the 50th and 75th percentiles were calculated as the achievable and reference levels, respectively. In adults, the 75th percentile CTDIvol values were 86, 34, 24, 26, 24, and 38 mGy for the head, head and neck, thorax, upper abdomen, pelvis, and female pelvis, respectively. These values are generally higher than DRLs in several other countries but comparable to Japan’s DRLs in 2025. For pediatric head scans, the CTDIvol ranged from 59 to 74 mGy (75th percentile) across the age groups. The corresponding DLP ranged from 1469 to 2175 mGy·cm. The 75th percentiles of the CTDIvol were 25 and 18 mGy for the upper abdomen and whole body, respectively. This is the first multicenter study in Japan to propose LDRLs for planning CT scans, including pediatric cases. These findings support national dose optimization initiatives and provide a foundation for the establishment of NDRLs for radiotherapy.

Indexed as

East Asian PeopleHospitals, UniversityRadiotherapy Planning, Computer-AssistedTomography, X-Ray ComputedAdolescentAdultAgedChildChild, PreschoolDiagnostic Reference LevelsFemaleHumansInfantJapanMaleMiddle AgedCTDIvolDLPLocal DRLsPlanning CTRadiotherapy

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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.