Evidence map›Paper›PMID 35342953›Full record

ArticleMedical physics2022

A high-resolution dose calculation engine for X-ray microbeams radiation therapy.

Sarvenaz Keshmiri, Sylvan Brocard, Raphaël Serduc, Jean-François Adam

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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 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

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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

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3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

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4 · The record

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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.

Sarvenaz KeshmiriUniversité Grenoble-Alpes, UGA/INSERM UA7 STROBE, 2280 rue de la Piscine, Saint-Martin d'Hères, 38400, France.
Sylvan BrocardUniversité Grenoble-Alpes, UGA/INSERM UA7 STROBE, 2280 rue de la Piscine, Saint-Martin d'Hères, 38400, France.
Raphaël SerducUniversité Grenoble-Alpes, UGA/INSERM UA7 STROBE, 2280 rue de la Piscine, Saint-Martin d'Hères, 38400, France.
Jean-François AdamUniversité Grenoble-Alpes, UGA/INSERM UA7 STROBE, 2280 rue de la Piscine, Saint-Martin d'Hères, 38400, France.

Funding

LabEx PRIMES ANR-11-LABX-0063/ANR-1-IDEX-0007
6 · The paper itself

Abstract

backgroundMicrobeam radiation therapy (MRT) is a treatment modality based on spatial fractionation of synchrotron generated X-rays into parallel, high dose, microbeams of a few microns width. MRT is still an underdevelopment radiosurgery technique for which, promising preclinical results on brain tumors and epilepsy encourages its clinical transfer. PURPOSE: A safe clinical transfer of MRT needs a specific treatment planning system (TPS) that provides accurate dose calculations in human patients, taking into account the MRT beam's properties (high-dose gradients, spatial fractionation, polarization effects). So far, the most advanced MRT TPS, based on a hybrid dose calculation algorithm, is limited to a macroscopic rendering of the dose and does not account for the complex dose distribution inherent to MRT if delivered as conformal irradiations with multiple incidences. For overcoming these limitations, a multi-scale full Monte-Carlo calculation engine called penMRT has been developed and benchmarked against two general-purpose Monte Carlo (MC) codes: penmain based on PENELOPE and Gate based on Geant4.

methodsPenMRT, is based on the PENELOPE (2018) MC code, modified to take into account the voxelized geometry of the patients (computed tomography [CT]-scans) and is offering an adaptive micrometric dose calculation grid independent of the CT size, location, and orientation. The implementation of the dynamic memory allocation in penMRT, makes the simulations feasible within a huge number of dose scoring bins. The possibility of using a source replication approach to simulate arrays of microbeams, and the parallelization using OpenMPI have been added to penMRT in order to increase the calculation speed for clinical usages. This engine can be implemented in a TPS as a dose calculation core.

resultsThe performance tests highlight the reliability of penMRT to be used for complex irradiation conditions in MRT. The benchmarking against a standard PENELOPE code did not show any significant difference for calculations in centimetric beams, for a single microbeam and for a microbeam array. The comparisons between penMRT and Gate as an independent MC code did not show any difference in the beam paths, whereas, in valley regions, relative differences between the two codes rank from 1% to 7.5% which are probably due to the differences in physics lists that are used in these two codes. The reliability of the source replication approach has also been tested and validated with an underestimation of no more than 0.6% in low-dose areas.

conclusionsGood agreements (a relative difference between 0% and 8%) were found when comparing calculated peak to valley dose ratio values using penMRT, for irradiations with a full microbeam array, with calculated values in the literature. The high-resolution calculated dose maps obtained with penMRT are used to extract differential and cumulative dose-volume histograms (DVHs) and analyze treatment plans with much finer metrics regarding the irradiation complexity. To our knowledge, these are the first high-resolution dose maps and associated DVHs ever obtained for cross-fired microbeams irradiation, which is bringing a significant added value to the field of treatment planning in spatially fractionated radiation therapy.

Indexed as

X-Ray TherapyHumansMonte Carlo MethodRadiotherapy DosageRadiotherapy Planning, Computer-AssistedReproducibility of ResultsSynchrotronsX-Raysdose calculation enginemedium energy X-raysmicrobeam radiation therapymicrometric dose calculation gridsMonte Carlo methodsynchrotron radiation

Identifiers

PMID35342953
PMCPMC9322281

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LicenceCC BY-NC-ND
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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.