Evidence map›Paper›PMID 34199881›Full record

ArticleCancers2021

Interfractional Geometric Variations and Dosimetric Benefits of Stereotactic MRI Guided Online Adaptive Radiotherapy (SMART) of Prostate Bed after Radical Prostatectomy: Post-Hoc Analysis of a Phase II Trial.

Minsong Cao, Yu Gao, Stephanie M Yoon, Yingli Yang, Ke Sheng, Leslie K Ballas, Vincent Basehart, Ankush Sachdeva, Carol Felix, Daniel A Low and 2 more

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

Article in Cancers, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers.

0numbers the graph read from it
0cells of the map it votes in
14citing papers in PubMed
4.4field-weighted citation impact, top 5% 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

14 citing papers in PubMed, 18 citations in OpenAlex.

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  7. Surrogate gating strategies for the Elekta Unity MR-Linac gating system.Journal of applied clinical medical physics · 2025
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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

12 authors at 2 institutions in 1 country.

Minsong CaoDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Yu GaoDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Stephanie M YoonDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Yingli YangDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Ke ShengDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Leslie K BallasDepartment of Radiation Oncology, University of Southern California, Los Angeles, CA 90089, USA.
Vincent BasehartDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Ankush SachdevaDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Carol FelixDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Daniel A LowDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Michael L SteinbergDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Amar U KishanDepartment of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
University of California, Los Angeles · USUniversity of Southern California · US

Funding

ViewRay Inc. Industrial Grant
6 · The paper itself

Abstract

purposeTo evaluate geometric variations of patients receiving stereotactic body radiotherapy (SBRT) after radical prostatectomy and the dosimetric benefits of stereotactic MRI guided adaptive radiotherapy (SMART) to compensate for these variations. MATERIALS/

methodsThe CTV and OAR were contoured on 55 MRI setup scans of 11 patients treated with an MR-LINAC and enrolled in a phase II trial of post-prostatectomy SBRT. All patients followed institutional bladder and rectum preparation protocols and received five fractions of 6-6.8 Gy to the prostate bed. Interfractional changes in volume were calculated and shape deformation was quantified by the Dice similar coefficient (DSC). Changes in CTV-V95%, bladder and rectum maximum dose, V32.5Gy and V27.5Gy were predicted by recalculating the initial plan on daily MRI. SMART was retrospectively simulated if the predicted dose exceeded pre-set criteria.

resultsThe CTV volume and shape remained stable with a median volumetric change of 3.0% (IQR -3.0% to 11.5%) and DSC of 0.83 (IQR 0.79 to 0.88). Relatively large volumetric changes in bladder (median -24.5%, IQR -34.6% to 14.5%) and rectum (median 5.4%, IQR - 9.7% to 20.7%) were observed while shape changes were moderate (median DSC of 0.79 and 0.73, respectively). The median CTV-V95% was 98.4% (IQR 94.9% to 99.6%) for the predicted doses. However, SMART would have been deemed beneficial for 78.2% of the 55 fractions based on target undercoverage (16.4%), exceeding OAR constraints (50.9%), or both (10.9%). Simulated SMART improved the dosimetry and met dosimetric criteria in all fractions. Moderate correlations were observed between the CTV-V95% and target DSC (R2 = 0.73) and bladder mean dose versus volumetric changes (R2 = 0.61).

conclusionsInterfractional dosimetric variations resulting from anatomic deformation are commonly encountered with post-prostatectomy RT and can be mitigated with SMART.

Indexed as

MRgRTMR guided adaptive radiotherapypost-prostatectomyprostate cancerstereotactic body radiotherapy SBRT

Identifiers

PMID34199881
PMCPMC8200117
OpenAlexW3169064172

What OpenQuestion 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 OpenQuestion graph.