Evidence map›Paper›PMID 42234857›Full record

ArticleJournal of radiation research2026

For ultra-high dose rate carbon-ion irradiation, comparable beam parameters induce the equivalent cell sparing (FLASH) effect.

Kento Tsubouchi, Yukari Yoshida, Masashi Yagi, Kazumasa Minami, Hiromu Suda, Masao Nakao, Ken Yusa, Mutsumi Tashiro, Shinichi Shimizu, Tatsuya Ohno and 1 more

Abstract read
In one paragraph

Article in Journal of radiation research, 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

11 authors.

Kento TsubouchiDepartment of Carbon Ion Radiotherapy, The University of Osaka Graduate School of Medicine, 2‑2 Yamada‑oka, Suita, Osaka 565-0871, Japan.ORCID 0009-0008-2035-1306
Yukari YoshidaGunma University Heavy Ion Medical Center, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
Masashi YagiDivision of Radiation Oncology, National Cancer Centre Singapore, 30 Hospital Boulevard, Singapore 168583, Singapore.
Kazumasa MinamiDivision of Health Science, The University of Osaka Graduate School of Medicine, 1-7 Yamada-oka, Suita, Osaka 565-0871, Japan.ORCID 0000-0002-3864-6478
Hiromu SudaGunma University Heavy Ion Medical Center, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
Masao NakaoGunma University Heavy Ion Medical Center, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
Ken YusaGunma University Heavy Ion Medical Center, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
Mutsumi TashiroGunma University Heavy Ion Medical Center, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
Shinichi ShimizuDepartment of Carbon Ion Radiotherapy, The University of Osaka Graduate School of Medicine, 2‑2 Yamada‑oka, Suita, Osaka 565-0871, Japan.
Tatsuya OhnoGunma University Heavy Ion Medical Center, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.ORCID 0000-0002-6703-3144
Kazuhiko OgawaDepartment of Radiation Oncology, The University of Osaka Graduate School of Medicine, 2‑2 Yamada‑oka, Suita, Osaka 565-0871, Japan.

Funding

Japan Society for the Promotion of Science JP22K07695Japan Society for the Promotion of Science JP25K02605Japan Society for the Promotion of Science JP25K03435Japan Society for the Promotion of Science JP25K10467Japan Society for the Promotion of Science JP25K11008
6 · The paper itself

Abstract

Recently, ultra-high dose rate (uHDR) irradiation has received attention for FLASH effect, a phenomenon in vivo that reduces normal-tissue damage without compromising antitumor efficacy compared to normal dose rate (NDR) irradiation. Such protective responses observed in vitro are referred to as cell-sparing effect. In previous studies, the cell-sparing effect was demonstrated using a carbon-ion beam scanning system. This study aimed to reproduce comparable irradiation conditions using a different machine at another facility and evaluate the cell-sparing effect. Comparable beam settings were adopted: physical dose 7 Gy, average dose rates (ADR) 100 Gy/s for uHDR and 1 Gy/s for NDR, dose-averaged linear energy transfer (LETd) 16.3 and 50 keV/μm, and identical scanning patterns. The same cell lines, Human salivary gland cell line (HSGc-C5), human dermal fibroblast (HDF), and human lung bronchial epithelial cell line (Nuli-1), were irradiated under normoxia. Colony formation assay and immunofluorescence staining of γH2AX were performed to assess cell survival and DNA damage. Comparable physical dose, ADR, and field flatness were verified by measurements. HDF and Nuli-1 showed the cell-sparing effects with increased surviving fractions and less DNA damage, which were enhanced at higher LET. In contrast, HSGc-C5 exhibited the smaller cell-sparing effect, being absent at low LET. These results were largely consistent with previous studies. To the best of current knowledge, this study is the first to indicate that the cell-sparing effect depends not on irradiation devices but on beam parameters, contributing to accelerating further FLASH research and clinical implementation of carbon-ion uHDR irradiation.

Indexed as

CarbonHeavy Ion RadiotherapyCell LineCell SurvivalDNA DamageDose-Response Relationship, RadiationHumansLinear Energy TransferCarboncarbon ion beamcell sparing effectdifferent facilitydifferent machinesflash effect

Identifiers

PMID42234857
PMCPMC13400559

What Socratic 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 Socratic graph.