Evidence map›Paper›PMID 37370239›Full record

ArticleMedical physics2023

PETRA: A pencil beam trimming algorithm for analytical proton therapy dose calculations with the dynamic collimation system.

Laura C Bennett, Daniel E Hyer, Kevin Erhart, Nicholas P Nelson, Wesley S Culberson, Blake R Smith, Patrick M Hill, Ryan T Flynn

Open access · hybridAbstract read
In one paragraph

Article in Medical physics, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed
1.0field-weighted citation impact, top 21% 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

5 citing papers in PubMed, 4 citations in OpenAlex.

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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

8 authors at 4 institutions in 1 country.

Laura C BennettRoy J. Carver Department of Biomedical Engineering, University of Iowa, 5601 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa, USA.
Daniel E HyerDepartment of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA.
Kevin Erhart.decimal LLC, Sanford, Florida, USA.
Nicholas P NelsonDepartment of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA.
Wesley S CulbersonDepartment of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA.
Blake R SmithDepartment of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA.
Patrick M HillDepartment of Human Oncology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA.
Ryan T FlynnDepartment of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA.
University of Iowa Hospitals and Clinics · USUniversity of Wisconsin–Madison · USSanford Health · USUniversity of Iowa · US

Funding

Sharpening the edge in pencil-beam proton therapy: an aftermarket collimation system to better spare normal tissue during radiation treatmentR37CA226518 · NCI · UNIVERSITY OF IOWA · PI HYER, DANIEL ELLIS · 2018 to 2024
$3.1M
NCI NIH HHS R37 CA226518
6 · The paper itself

Abstract

backgroundThe Dynamic Collimation System (DCS) has been shown to produce superior treatment plans to uncollimated pencil beam scanning (PBS) proton therapy using an in-house treatment planning system (TPS) designed for research. Clinical implementation of the DCS requires the development and benchmarking of a rigorous dose calculation algorithm that accounts for pencil beam trimming, performs monitor unit calculations to produce deliverable plans at all beam energies, and is ideally implemented with a commercially available TPS. PURPOSE: To present an analytical Pencil bEam TRimming Algorithm (PETRA) for the DCS, with and without its range shifter, implemented in the Astroid TPS (.decimal, Sanford, Florida, USA). MATERIALS: PETRA was derived by generalizing an existing pencil beam dose calculation model to account for the DCS-specific effects of lateral penumbra blurring due to the nickel trimmers in two different planes, integral depth dose variation due to the trimming process, and the presence and absence of the range shifter. Tuning parameters were introduced to enable agreement between PETRA and a measurement-validated Dynamic Collimation Monte Carlo (DCMC) model of the Miami Cancer Institute's IBA Proteus Plus system equipped with the DCS. Trimmer position, spot position, beam energy, and the presence or absence of a range shifter were all used as variables for the characterization of the model. The model was calibrated for pencil beam monitor unit calculations using procedures specified by International Atomic Energy Agency Technical Report Series 398 (IAEA TRS-398).

resultsThe integral depth dose curves (IDDs) for energies between 70 MeV and 160 MeV among all simulated trimmer combinations, with and without the ranger shifter, agreed between PETRA and DCMC at the 1%/1 mm 1-D gamma criteria for 99.99% of points. For lateral dose profiles, the median 2-D gamma pass rate for all profiles at 1.5%/1.5 mm was 99.99% at the water phantom surface, plateau, and Bragg peak depths without the range shifter and at the surface and Bragg peak depths with the range shifter. The minimum 1.5%/1.5 mm gamma pass rates for the 2-D profiles at the water phantom surface without and with the range shifter were 98.02% and 97.91%, respectively, and, at the Bragg peak, the minimum pass rates were 97.80% and 97.5%, respectively.

conclusionThe PETRA model for DCS dose calculations was successfully defined and benchmarked for use in a commercially available TPS.

Indexed as

Proton TherapyAlgorithmsMonte Carlo MethodPhantoms, ImagingRadiotherapy DosageRadiotherapy Planning, Computer-AssistedWaterWatercollimationdose calculationdynamic collimationdynamic collimation system (DCS)pencil beam scanning (PBS)proton therapyspot scanning

Identifiers

PMID37370239
PMCPMC10751389
OpenAlexW4382343983

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.