Evidence map›Paper›PMID 42050792›Full record

ArticleJournal of applied clinical medical physics2026

Use of apertures in single-energy pristine Bragg peak FLASH radiotherapy.

Yangguang Ma, Balaji Selvaraj, Xingyi Zhao, Chingyun Cheng, Chin-Cheng Chen, Longfei Diao, Yufei Wang, Zhengda Wang, Yuntong Pei, Lele Liu and 6 more

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Journal of applied clinical medical physics, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

1 citing paper in PubMed.

  1. Article
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

16 authors.

Yangguang MaDepartment of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.ORCID https://orcid.org/0000-0002-1333-163X
Balaji SelvarajNew York Proton Center, New York, New York, USA.
Xingyi ZhaoNew York Proton Center, New York, New York, USA.
Chingyun ChengDepartment of Radiation Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
Chin-Cheng ChenDepartment of Radiation Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.
Longfei DiaoSchool of Physics, Peking University, Beijing, China.ORCID https://orcid.org/0009-0001-3095-5065
Yufei WangSchool of Software Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Zhengda WangSchool of Software Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Yuntong PeiDepartment of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
Lele LiuDepartment of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
Xueqing YanSchool of Physics, Peking University, Beijing, China.
Benjamin DurkeeDepartment of Radiation Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
Charles B SimoneNew York Proton Center, New York, New York, USA.
Haibo LinNew York Proton Center, New York, New York, USA.
Xuanqin MouSchool of Information and Communications Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Minglei KangDepartment of Radiation Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundProton single-energy Bragg peak (SEBP) FLASH delivery can achieve dosimetric distributions equivalent to conventional intensity-modulated proton therapy (IMPT). However, range-pulling and field compensator devices enlarge the proton pencil beam spot size, increasing lateral penumbra and compromising dose conformality and high-dose-rate distribution. Apertures are employed to mitigate these effects, enhancing dose metrics while preserving ultra-high dose rate performance. PURPOSE: To investigate the efficacy of apertures in sharpening lateral dose falloff and enhancing dose conformity in proton pencil beam scanning (PBS) Bragg peak (BP) FLASH radiotherapy (RT), addressing increased lateral dose spillage caused by universal range shifter (URS) and range compensator (RC) usage.

methodsPBS Single-energy BP (SEBP) FLASH treatment plans with and without brass apertures were optimized using an in-house planning system. Dose and dose rate characteristics were simulated using MCSquare. Penumbra reduction was assessed in a water phantom for 3 and 5 cm square fields under varying pullback (10 cm, 20 cm. 30 cm) and air gap (5 cm, 10 cm, 15 cm) conditions. Aperture effects were evaluated at the entrance, midpoint, and BP positions. The rGBM cancer plan was optimized using SEBP with various dose thresholds (0, 2, and 5 Gy) applied to analyze dose and ultra-high dose rate (V

resultsUse of aperture significantly reduced lateral penumbra across all spatial positions. The degree of penumbra reduction increased significantly with the increased pullback, and the reduction effect at the BP was generally comparable to that at the entrance. The 5 cm field generally showed greater penumbra reduction than the 3 cm field. In the rGBM case, apertures improved gross tumor volume (GTV) dose conformity and reduced organ-at-risk (OAR) exposure but decreased ultra-high dose rate coverage for both GTV and OARs. The ultra-high dose rate coverage of GTV was not affected by the dose threshold, while the ultra-high dose rate coverage of the brain increased with the increasing dose threshold.

conclusionApertures effectively reduce lateral penumbra and dose spalliage to OARs, improving target dose conformity in range shifter-based SEBP FLASH-RT. They also can reduce ultra-high dose-rate exposure to critical OARs in the low-dose region while maintaining the FLASH ratio in the high-dose region.

Indexed as

NeoplasmsOrgans at RiskPhantoms, ImagingProton TherapyRadiotherapy Planning, Computer-AssistedHumansRadiotherapy DosageRadiotherapy, Intensity-ModulatedapertureBragg peak FLASH radiotherapypenumbra reductionproton pencil beam scanning

Identifiers

PMID42050792
PMCPMC13125415

What Socratic holds

Textmetadata
LicenceCC BY
Read underepoch 390

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 Socratic graph.