{
  "abstract": "Background and purpose: Clinical proton pencil beam scanning systems use dose-driven delivery, limiting operation at ultra-high dose rates required for FLASH radiotherapy. Time-driven spot delivery, controlled by irradiation time rather than monitor chamber feedback, may enable FLASH operation. We implemented a non-clinical time-driven FLASH strategy on a clinical proton PBS system and experimentally validated its performance. Materials and methods: FLASH delivery was achieved by increasing beamline transmission through the energy-selection system and replacing dose-driven spot control with time-driven delivery in the Scanning Controller Diagnostic mode. Beam transmission was evaluated at gantry angle 0°. Depth-dose distributions, beam optics, scanning accuracy and uniform field generation were assessed for 228.4 MeV protons at gantry angles of 0°, 180° and 270°. Results: Opening the ESS divergence-limiting slits increased beamline transmission from 8% to 57%, resulting in approximately 273 nA at the isocentre (1.7 × 10 12 protons s −1 ) and an estimated peak on-axis average dose rate of 2.0 × 10 3 Gy s −1 . An 11 × 11 spot field delivered 25 Gy in approximately 0.6 s, corresponding to an average field dose rate of 42 Gy s −1 , with up to 90 Gy s −1 measured at higher doses. Proton range and Bragg peak width remained unchanged. Spot position deviations were below 0.5 mm, and uniform 4 × 4 cm 2 fields with <3% flatness were achieved. Conclusions: Time-driven delivery enables experimental proton PBS operation at UHDR while maintaining beam characteristics suitable for reproducible dosimetry and radiobiological studies, providing a practical and experimentally characterised platform for preclinical proton PBS FLASH research.",
  "abstract_shown": true,
  "affiliations": [
    "Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, PL-31342, Poland",
    "Corresponding author."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 17,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Dawid Krzempek"
    },
    {
      "affs": [
        0
      ],
      "name": "Jan Gajewski"
    },
    {
      "affs": [
        0
      ],
      "name": "Hubert Jabłoński"
    },
    {
      "affs": [
        0
      ],
      "name": "Anna Spaleniak"
    },
    {
      "affs": [
        0
      ],
      "name": "Wiktor Komenda"
    },
    {
      "affs": [
        0
      ],
      "name": "Konrad Guguła"
    },
    {
      "affs": [
        0
      ],
      "name": "Michał Kamiński"
    },
    {
      "affs": [
        0
      ],
      "name": "Michał Hankiewicz"
    },
    {
      "affs": [
        0
      ],
      "name": "Tomasz Pasiecznik"
    },
    {
      "affs": [
        0
      ],
      "name": "Krzysztof Suder"
    },
    {
      "affs": [
        0
      ],
      "name": "Leszek Malinowski"
    },
    {
      "affs": [
        0
      ],
      "name": "Tomasz Nowak"
    },
    {
      "affs": [
        0
      ],
      "name": "Natalia Mojżeszek"
    },
    {
      "affs": [
        0
      ],
      "name": "Marta Bałamut"
    },
    {
      "affs": [
        0
      ],
      "name": "Paweł Rogalski"
    },
    {
      "affs": [
        0
      ],
      "name": "Renata Kopeć"
    },
    {
      "affs": [
        1
      ],
      "name": "Marzena Rydygier"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dwt2jwh4zqjx9.bib",
  "cited_by": 0,
  "doi": "10.1016/j.phro.2026.101110",
  "fulltext_url": "http://www.sciencedirect.com/science/article/pii/S2405631626002101",
  "id": "dwt2jwh4zqjx9",
  "issns": [
    "2405-6316"
  ],
  "landing_url": "https://doi.org/10.1016/j.phro.2026.101110",
  "language": "en",
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Original Research Article"
    ],
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      "lcc",
      "R895-920"
    ],
    [
      "lcc",
      "RC254-282"
    ],
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      "openalex",
      "2740|Radiation Therapy and Dosimetry"
    ]
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  "pdf_url": "https://www.phiro.science/article/S2405-6316(26)00210-1/pdf",
  "pmcid": "PMC13717095",
  "pmid": "42959518",
  "published": "2026-10-10",
  "publisher": "Elsevier",
  "ris": "https://research.draconitic.com/paper/dwt2jwh4zqjx9.ris",
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  "subjects": [
    {
      "field": "medicine",
      "origin": "lcc:RC254-282",
      "subfield": "oncology"
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  ],
  "title": "Experimental validation of time-driven proton PBS FLASH delivery on a clinical proton therapy system",
  "title_text": "Experimental validation of time-driven proton PBS FLASH delivery on a clinical proton therapy system",
  "type": "peer-reviewed",
  "updated_at": "2026-11-02T12:21:28Z",
  "url": "https://research.draconitic.com/paper/dwt2jwh4zqjx9",
  "venue": "Physics and Imaging in Radiation Oncology",
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}