Evidence map›Paper›PMID 35912253›Full record

ArticleFrontiers in oncology2022

Urethral Interfractional Geometric and Dosimetric Variations of Prostate Cancer Patients: A Study Using an Onboard MRI.

Jonathan Pham, Ricky R Savjani, Stephanie M Yoon, Tiffany Yang, Yu Gao, Minsong Cao, Peng Hu, Ke Sheng, Daniel A Low, Michael Steinberg and 2 more

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Frontiers in oncology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing 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

3 citing papers in PubMed.

  1. Review
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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.

Jonathan PhamDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.
Ricky R SavjaniDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.
Stephanie M YoonDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.
Tiffany YangDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.
Yu GaoDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.
Minsong CaoDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.
Peng HuDepartment of Radiology, University of California, Los Angeles, Los Angeles, CA, United States.
Ke ShengDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.
Daniel A LowDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.
Michael SteinbergDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.
Amar U KishanDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.
Yingli YangDepartment of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Purpose: For a cohort of prostate cancer patients treated on an MR-guided radiotherapy (MRgRT) system, we retrospectively analyzed urethral interfractional geometric and dosimetric variations based on onboard MRIs acquired at different timepoints and evaluated onboard prostatic urethra visualization for urethra-focused online adaptive RT. Methods: Twenty-six prostate cancer patients were prospectively scanned on a 0.35-T MRgRT system using an optimized T2-weighted HASTE sequence at simulation and final fraction. Two radiation oncologists (RO1 and RO2) contoured the urethras on all HASTE images. The simulation and final fraction HASTE images were rigidly registered, and urethral interobserver and interfractional geometric variation was evaluated using the 95th percentile Hausdorff distance (HD95), mean distance to agreement (MDA), center-of-mass shift (COMS), and DICE coefficient. For dosimetric analysis, simulation and final fraction HASTE images were registered to the 3D bSSFP planning MRI and 3D bSSFP final setup MRI, respectively. Both ROs' urethra contours were transferred from HASTE images for initial treatment plan optimization and final fraction dose estimation separately. Stereotactic body radiotherapy (SBRT) plans, 40 Gy in 5 fractions, were optimized to meet clinical constraints, including urethral V42Gy ≤0.03 cc, on the planning MRI. The initial plan was then forward calculated on the final setup MRI to estimate urethral dose on the final fraction and evaluate urethral dosimetric impact due to anatomy change. Results: The average interobserver HD95, MDA, COMS, and DICE were 2.85 ± 1.34 mm, 1.02 ± 0.36 mm, 3.16 ± 1.61 mm, and 0.58 ± 0.15, respectively. The average interfractional HD95, MDA, COMS, and DICE were 3.26 ± 1.54 mm, 1.29 ± 0.54 mm, 3.34 ± 2.01 mm, and 0.49 ± 0.18, respectively. All patient simulation MRgRT plans met all clinical constraints. For RO1 and RO2, 23/26 (88%) and 21/26 (81%) patients' final fraction estimated urethral dose did not meet the planned constraint. The average urethral V42Gy change was 0.48 ± 0.58 cc. Conclusion: Urethral interfractional motion and anatomic change can result in daily treatment violating urethral constraints. Onboard MRI with good visualization of the prostatic urethra can be a valuable tool to help better protect the urethra through patient setup or online adaptive RT.

Indexed as

dosimetryMR-guided radiation therapy (MRgRT)prostate cancertoxicityurethra

Identifiers

PMID35912253
PMCPMC9334678

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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.