Evidence map›Paper›PMID 41423134›Full record

ArticleRadiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology2026

Deliverable proton conformal FLASH radiotherapy treatment planning for head and neck re-irradiation patients.

Wei Zou, Lei Dong, Arnaud Pin, Rasmus Nilsson, Michele Kim, Ontida Apinorasethkul, Julia Pakela, Andrew Friberg, Brandon Koger, Rudi Labarbe and 10 more

Abstract read
In one paragraph

Article in Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing 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

2 citing papers in PubMed.

  1. Article
  2. Review
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

20 authors.

Wei ZouDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA. Electronic address: wei.zou@pennmedicine.upenn.edu.
Lei DongDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Arnaud PinIBA Proton Therapy, Louvain-La-Neuve, Belgium.
Rasmus NilssonRaySearch Laboratories, Stockholm, Sweden.
Michele KimDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Ontida ApinorasethkulDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Julia PakelaDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Andrew FribergDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Brandon KogerDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Rudi LabarbeIBA Proton Therapy, Louvain-La-Neuve, Belgium.
Carolina Llina FuentesIBA Proton Therapy, Louvain-La-Neuve, Belgium.
Keith CengelDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Erik TraneusRaySearch Laboratories, Stockholm, Sweden.
Swati GirdhaniIBA Proton Therapy, Louvain-La-Neuve, Belgium.
Costas KoumenisDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Francois Vander StappenIBA Proton Therapy, Louvain-La-Neuve, Belgium.
Eric DiffenderferDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Jeffrey BradleyDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Boon-Keng Kevin TeoDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Alexander LinDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.

Funding

Translational Studies in FLASH Particle RadiotherapyP01CA257904 · NCI · UNIVERSITY OF PENNSYLVANIA · PI Mary E. Putt · 2022 to 2026
$14.2M
NCI NIH HHS P01 CA257904
6 · The paper itself

Abstract

purposeClinical translation of ultra-high dose rate (UHDR) delivery to harness potential FLASH effect requires a treatment planning system (TPS) to optimize and calculate dose and dose rate in patients. Proton conformal FLASH treatment aims to deliver pencil beam scanning (PBS) Bragg Peaks to the tumor region with UHDR. In this work, we conducted a treatment planning study for head and neck (H&N) re-irradiation patients using a research-version of a commercial TPS paired with conformal FLASH hardware integrated into a nozzle of a clinical cyclotron-based system.

methodsFifteen H&N patients were planned for re-irradiation of 40 GyRBE in 5 fractions to the area of intact tumor. The TPS was configured with validated UHDR beam measurement to generate optimized patient FLASH plans with one or two beams, delivered as single-beam-per-fraction (SBPF). Each beam consists of a deliverable mono-energetic PBS map, a 3D-printable conformal energy modulator design, a selection of aluminum range shifter plates, and a brass aperture. Python scripts with machine-specific delivery timing parameters were used for Monte Carlo dose and dose rate calculations. Clinical VMAT and IMPT plans were also generated for dosimetric comparison.

resultsAll plans met the tumor target and OAR planning objectives. Conformal FLASH plans showed very similar dose distributions to the clinical IMPT plans. Compared to VMAT plans, both IMPT and FLASH plans have reduced low dose region, maximum cord dose D0.03 cc (8.37 ± 0.94 vs. 3.19 ± 3.81 and 4.32 ± 3.12 GyRBE, respectively), contra-lateral parotid mean dose (1.88 ± 0.99 vs. 0.00 ± 0.01 and 0.00 ± 0.00 GyRBE, respectively) and contra-lateral submandibular gland mean dose (2.49 ± 1.06 vs. 0.14 ± 0.13 and 0.19 ± 0.19 GyRBE, respectively). With 500 nA quasi-continuous nozzle beam current, the mean dose-averaged dose rate in CTVs of these 15 patients achieved 95.75 ± 22.78 Gy/s.

conclusionsWe report the deliverable proton conformal FLASH treatment plans for H&N re-irradiation patients using the innovative hardware configuration and measured beam data in our institution. The FLASH plans have very similar plan qualities to clinical IMPT proton plans and were deliverable with our proton machine. The machine specific 3D dose rate distribution can be calculated and displayed in the TPS.

Indexed as

Head and Neck NeoplasmsProton TherapyRadiotherapy, ConformalRadiotherapy Planning, Computer-AssistedRe-IrradiationHumansRadiotherapy DosageConformal FLASHHead & neck cancerRe-irradiationUltra-high dose rate

Identifiers

PMID41423134
PMCPMC13151878

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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.