Evidence map›Paper›PMID 41634712›Full record

ArticleRadiation oncology (London, England)2026

Revisiting fractionation in prostate carbon ion therapy: first comparative analysis of biologically effective dose using mMKM with diverse parameters.

Chi-Chuan Chiou, Yu-Ming Liu, Keng-Li Lan, Yuan-Hung Wu, Tzu-Yu Lai, Yu-Mei Kang, Jui-Pin Chen, Yu-Wen Hu

Abstract readComparative Study
In one paragraph

Article in Radiation oncology (London, England), 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

8 authors.

Chi-Chuan ChiouDepartment of Heavy Particles and Radiation Oncology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shipai Rd., Beitou District, Taipei City, 11217, Taiwan.
Yu-Ming LiuDepartment of Heavy Particles and Radiation Oncology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shipai Rd., Beitou District, Taipei City, 11217, Taiwan.
Keng-Li LanDepartment of Heavy Particles and Radiation Oncology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shipai Rd., Beitou District, Taipei City, 11217, Taiwan.
Yuan-Hung WuDepartment of Heavy Particles and Radiation Oncology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shipai Rd., Beitou District, Taipei City, 11217, Taiwan.
Tzu-Yu LaiDepartment of Heavy Particles and Radiation Oncology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shipai Rd., Beitou District, Taipei City, 11217, Taiwan.
Yu-Mei KangDepartment of Heavy Particles and Radiation Oncology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shipai Rd., Beitou District, Taipei City, 11217, Taiwan.
Jui-Pin ChenDepartment of Heavy Particles and Radiation Oncology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shipai Rd., Beitou District, Taipei City, 11217, Taiwan.
Yu-Wen HuDepartment of Heavy Particles and Radiation Oncology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shipai Rd., Beitou District, Taipei City, 11217, Taiwan. ywhu@vghtpe.gov.tw.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundCarbon ion radiotherapy (CIRT) for prostate cancer has evolved from conventional regimens [66 Gy(RBE)/20 fractions (66G20), 63 Gy(RBE)/20 fractions (63G20)] toward hypofractionated schedules [57.6 Gy(RBE)/16 fractions (57.6G16), 51.6 Gy(RBE)/12 fractions (51.6G12), and 40 Gy(RBE)/4 fractions (40G4)]. Whether these are biologically equivalent remains unclear. To our knowledge, this is the first study to systematically evaluate the biological effects of these regimens using the modified microdosimetric kinetic model (mMKM) across diverse parameter settings.

methodsBiologically effective dose (BED) was calculated using four approaches: (1) photon linear-quadratic (LQ) model (2), modified microdosimetric kinetic model (mMKM) with human salivary gland parameters and fixed RBE of 2.41 (3), mMKM3.1, and (4) mMKM with varied domain radius (0.2–0.5 μm) and α/β (1.5–10 Gy). Tumor control probability (TCP) was further estimated based on a reanalysis of the Ion Prostate Irradiation trial.

resultsPhoton LQ analysis suggested near-equivalent BEDs for 63G20, 57.6G16, and 51.6G12 (~ 200 Gy and ~ 130 Gy for α/β = 1.5 and 3 Gy), with 40G4 markedly higher. In contrast, all mMKM-based methods showed progressive BED reductions with hypofractionation versus 63G20 (–16.8% to − 11.3% for 51.6G12; − 30.4% to − 5.2% for 40G4). TCP decreased by 15.5% for 51.6G12 and 28.7% for 40G4. mMKM also yielded higher effective α/β values for CIRT, reflecting reduced fractionation sensitivity.

conclusionsmMKM-based modeling challenges the assumption of dose equivalence in hypofractionated prostate CIRT, suggesting potential underdosing risks. This parameter-sensitive analysis underscores the need for biologically robust models to refine dose prescription and optimize outcomes in particle therapy. CLINICAL TRIAL NUMBER: Not applicable.

Indexed as

Dose Fractionation, RadiationHeavy Ion RadiotherapyProstatic NeoplasmsHumansMaleModels, BiologicalRadiotherapy Planning, Computer-AssistedRelative Biological EffectivenessBEDCIRTmMKMProstate

Identifiers

PMID41634712
PMCPMC12922387

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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.