Evidence map›Paper›PMID 33058211›Full record

ArticleMedical physics2020

First experimental investigation of simultaneously tracking two independently moving targets on an MRI-linac using real-time MRI and MLC tracking.

Paul Z Y Liu, Bing Dong, Doan Trang Nguyen, Yuanyuan Ge, Emily A Hewson, David E J Waddington, Ricky O'Brien, Gary P Liney, Paul J Keall

Abstract read
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In one paragraph

Article in Medical physics, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers.

0numbers the graph read from it
0cells of the map it votes in
16citing 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

16 citing papers in PubMed.

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4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

9 authors.

Paul Z Y LiuACRF Image X Institute, University of Sydney Central Clinical School, Sydney, NSW, Australia.
Bing DongDepartment of Medical Physics, Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia.
Doan Trang NguyenACRF Image X Institute, University of Sydney Central Clinical School, Sydney, NSW, Australia.
Yuanyuan GeACRF Image X Institute, University of Sydney Central Clinical School, Sydney, NSW, Australia.
Emily A HewsonACRF Image X Institute, University of Sydney Central Clinical School, Sydney, NSW, Australia.
David E J WaddingtonACRF Image X Institute, University of Sydney Central Clinical School, Sydney, NSW, Australia.
Ricky O'BrienACRF Image X Institute, University of Sydney Central Clinical School, Sydney, NSW, Australia.
Gary P LineyDepartment of Medical Physics, Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia.
Paul J KeallACRF Image X Institute, University of Sydney Central Clinical School, Sydney, NSW, Australia.

Funding

Australian Government NHMRC ProgramCancer Council NSWCancer Institute NSW fellowshipsNHMRC Early Career FellowshipNHMRC Senior Principal Research Fellowship
6 · The paper itself

Abstract

purposeHigh quality radiotherapy is challenging in cases where multiple targets with independent motion are simultaneously treated. A real-time tumor tracking system that can simultaneously account for the motion of two targets was developed and characterized.

methodsThe multitarget tracking system was implemented on a magnetic resonance imaging (MRI)-linac and utilized multi-leaf collimator (MLC) tracking to adapt the radiation beam to phantom targets reproducing motion with prostate and lung motion traces. Multitarget tracking consisted of three stages: (a) pretreatment aperture segmentation where the treatment aperture was divided into segments corresponding to each target, (b) MR imaging where the positions of the two targets were localized, and (c) MLC tracking where an updated treatment aperture was calculated. Electronic portal images (EPID) acquired during irradiation were analyzed to characterize geometric uncertainty and tracking latency.

resultsMultitarget MLC tracking effectively accounted for the motion of both targets during treatment. The root-mean-square error between the centers of the targets and the centers of the corresponding MLC leaves were reduced from 5.5 mm without tracking to 2.7 mm with tracking for lung motion traces and reduced from 4.2 to 1.4 mm for prostate motion traces. The end-to-end latency of tracking was measured to be 328 ± 44 ms.

conclusionsWe have demonstrated the first experimental implementation of MLC tracking for multiple targets having independent motion. This technology takes advantage of the imaging capabilities of MRI-linacs and would allow treatment margins to be reduced in cases where multiple targets are simultaneously treated.

Indexed as

Particle AcceleratorsRadiotherapy, Intensity-ModulatedHumansMagnetic Resonance ImagingMotionPhantoms, ImagingRadiotherapy Planning, Computer-AssistedMLC trackingMRI-guided radiotherapyMRI-linac

Identifiers

PMID33058211

What OpenQuestion holds

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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.