Evidence map›Paper›PMID 39528113›Full record

ArticleRadiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology2025

Proton FLASH-arc therapy (PFAT): A feasibility study for meeting FLASH dose-rate requirements in the clinic.

Bethany Rothwell, Alejandro Bertolet, Jan Schuemann

Abstract read
In one paragraph

Article in Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing 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

4 citing papers in PubMed.

  1. Review
  2. Review
  3. Review
  4. In response to Yu and Chen: Proton FLASH-Arc Therapy: Bridging feasibility to clinical utility.Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology · 2025
    Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

3 authors.

Bethany RothwellPhysics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA. Electronic address: brothwell1@mgh.harvard.edu.
Alejandro BertoletPhysics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA. Electronic address: abertoletreina@mgh.harvard.edu.
Jan SchuemannPhysics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA. Electronic address: jschuemann@mgh.harvard.edu.

Funding

Using experimentally-guided multi-scale modeling to determining the mechanism of FLASH tissue sparingR01CA266419 · NCI · MASSACHUSETTS GENERAL HOSPITAL · PI SCHUEMANN, JAN PATRICK OSCAR · 2022 to 2025
$3.3M
Dose-Rate Variations for Patient Treatments in Flash and conventional radiation therapyR21CA252562 · NCI · MASSACHUSETTS GENERAL HOSPITAL · PI SCHUEMANN, JAN PATRICK OSCAR · 2021 to 2022
$416k
NCI NIH HHS R01 CA266419NCI NIH HHS R21 CA252562
6 · The paper itself

Abstract

background and purposeProton arc therapy and FLASH radiotherapy (FLASH-RT) each offer unique advantages in proton therapy. However, clinical translation of FLASH-RT faces challenges in defining and delivering high dose rates. We propose the use of proton FLASH-arc therapy (PFAT) to leverage the benefits of arc while addressing FLASH delivery concerns by spatially fractionating dose delivery to healthy tissue. MATERIALS AND

methodsTreatment plans for an abdominal phantom and a clinical brain case were designed in OpenTPS, using monoenergetic beams within a 360-degree gantry rotation. Beams were optimized to achieve target coverage while maximizing spatial fractionation in non-target regions. The temporal dose delivery to healthy-tissue voxels, or in specified organs-at-risk (OARs), was constrained via selective spot removal in the beamlets matrix. The dose, LET, number of spots per voxel, and voxel-wise average dose rate were calculated for each PFAT plan and compared to a corresponding IMPT scenario.

resultsPFAT plans demonstrated comparable dose conformity to IMPT, with LET hotspots shifted towards the target center. The number of spots influencing healthy-tissue voxels was reduced, leading to regions of substantially higher dose rates in many points outside the target. OAR dose-rate optimization in the brain plan resulted in dose rates exceeding 40 Gy/s in the majority of points in the brainstem.

conclusionThe PFAT technique combines the advantages of FLASH and arc therapy, providing improved LET distributions and enhanced biological effect in the target, while achieving high dose rates in healthy tissue, thus reducing healthy tissue damage. This feasibility study demonstrates the capability of PFAT, setting the foundation for further optimization and application in diverse patient cases and complex geometries.

Indexed as

Brain NeoplasmsFeasibility StudiesPhantoms, ImagingProton TherapyRadiotherapy DosageRadiotherapy Planning, Computer-AssistedDose Fractionation, RadiationHumansOrgans at RiskRadiotherapy, Intensity-ModulatedFlash radiotherapyProton arc therapyTreatment planning

Identifiers

PMID39528113
PMCPMC11663118

What OpenQuestion holds

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Registered trials

None linked

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.