Evidence map›Paper›PMID 36222217›Full record

ArticleMedical physics2022

Dose and dose rate objectives in Bragg peak and shoot-through beam orientation optimization for FLASH proton therapy.

Pavitra Ramesh, Wenbo Gu, Dan Ruan, Ke Sheng

Open access · greenAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Medical physics, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
10citing papers in PubMed, 1 pooled it
2.0field-weighted citation impact, top 12% of its field
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

10 citing papers in PubMed, 1 synthesis or guideline pooled it, 14 citations in OpenAlex.

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  10. Emerging technologies for cancer therapy using accelerated particles.Progress in particle and nuclear physics · 2023
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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

4 authors at 2 institutions in 1 country.

Pavitra RameshDepartment of Radiation Oncology, University of California Los Angeles, Los Angeles, California, USA.
Wenbo GuDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Dan RuanDepartment of Radiation Oncology, University of California Los Angeles, Los Angeles, California, USA.
Ke ShengDepartment of Radiation Oncology, University of California Los Angeles, Los Angeles, California, USA.
University of California, Los Angeles · USUniversity of Pennsylvania · US

Funding

Development of an ultra-high dose rate rotational linac for FLASH RadiotherapyR01CA255432 · NCI · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · PI AGUSTSSON, RONALD, SHENG, KE · 2021 to 2025
$3.2M
Robust IMPT with automated beam orientation and scanning spot optimizationR01CA230278 · NCI · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · PI SHENG, KE · 2019 to 2023
$1.9M
NCI NIH HHS R01 CA230278NCI NIH HHS R01 CA255432NIH HHS R01CA230278NIH HHS R01CA255432
6 · The paper itself

Abstract

purposeThe combined use of Bragg peak (BP) and shoot-through (ST) beams has previously been shown to increase the normal tissue volume receiving FLASH dose rates while maintaining dose conformality compared to conventional intensity-modulated proton therapy (IMPT) methods. However, the fixed beam optimization method has not considered the effects of beam orientation on the dose and dose rates. To maximize the proton FLASH effect, here, we incorporate dose rate objectives into our beam orientation optimization framework.

methodsFrom our previously developed group-sparsity dose objectives, we add upper and lower dose rate terms using a surrogate dose-averaged dose rate definition and solve using the fast-iterative shrinking threshold algorithm. We compare the dosimetry for three head-and-neck cases between four techniques: (1) spread-out BP IMPT (BP), (2) dose rate optimization using BP beams only (BP-DR), (3) dose rate optimization using ST beams only (ST-DR), and (4) dose rate optimization using combined BP and ST (BPST-DR), with the goal of sparing organs at risk without loss of tumor coverage and maintaining high dose rate within a 10 mm region of interest (ROI) surrounding the clinical target volume (CTV).

resultsFor BP, BP-DR, ST-DR, and BPST-DR, CTV homogeneity index and Dmax were found to be on average 0.886, 0.867, 0.687, and 0.936 and 107%, 109%, 135%, and 101% of prescription, respectively. Although ST-DR plans were not able to meet dosimetric standards, BPST-DR was able to match or improve either maximum or mean dose in the right submandibular gland, left and right parotids, constrictors, larynx, and spinal cord compared to BP plans. Volume of ROIs receiving greater than 40 Gy/s (

conclusionsThe dose rate techniques, particularly BPST-DR, were able to significantly increase dose rate without compromising physical dose compared with BP. Our algorithm efficiently selects beams that are optimal for both dose and dose rate.

Indexed as

NeoplasmsProton TherapyRadiotherapy, Intensity-ModulatedHumansOrgans at RiskProtonsRadiotherapy DosageRadiotherapy Planning, Computer-AssistedProtonsdose optimizationFLASHproton

Identifiers

PMID36222217
PMCPMC9829523
OpenAlexW4304688600

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Registered trials

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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.