Evidence map›Paper›PMID 41799308›Full record

ArticleAdvances in radiation oncology2026

Optical Flow-Guided Analysis of Intrafractional Anatomical Variations in Pancreatic Tumors and Organs at Risk During Magnetic Resonance-Guided Adaptive Radiation Therapy Under Abdominal Compression.

Takanori Adachi, Nobutaka Mukumoto, Haruo Inokuchi, Naoki Mukumoto, Nobunari Hamaura, Hiroshige Itoyama, Yuki Hata, Mutsumi Yamagishi, Mai Sakagami, Kenji Hayashi and 3 more

Abstract read
In one paragraph

Article in Advances in radiation oncology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0cells of the map it votes in
0citing papers in PubMed
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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

0 citing papers in PubMed.

No citing paper in PubMed yet.

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

13 authors.

Takanori AdachiDepartment of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Nobutaka MukumotoDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Haruo InokuchiDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Naoki MukumotoDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Nobunari HamauraDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Hiroshige ItoyamaDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Yuki HataDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Mutsumi YamagishiDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Mai SakagamiDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Kenji HayashiDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Ryo OginoDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Mitsuhiro NakamuraDepartment of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Keiko ShibuyaDepartment of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Purpose: This study aimed to investigate intrafractional anatomic variations in pancreatic tumors and organs at risk (OARs) during magnetic resonance-guided adaptive radiation therapy (MRgART) using optical flow calculations. Methods and Materials: This study included 732,612 magnetic resonance (MR) slices from 345 fractions obtained from 25 consecutive patients with pancreatic cancer. All patients underwent MRgART using the Elekta Unity MR-Linac under abdominal compression. For each fraction, single-slice 2-dimensional cine MR images were acquired every 600 ms at the tumor center. On the first frames in the coronal and sagittal planes, the OARs (duodenum, stomach, small bowel, and colon) were delineated. Displacements were measured at 30-second intervals using the Farnebäck optical flow in the superior-inferior (SI) direction in the coronal and sagittal planes within the overlapping regions between each delineated structure and the rectangular region, with a side length of 10 cm centered on the tumor. To exclude outliers, range of motion in each direction was defined as the 2.5th-97.5th percentile of displacement, and statistical differences were assessed using the Wilcoxon signed-rank test with Holm-Bonferroni correction ( Results: The median SI range of motion of the tumor was 5.8 mm in both the coronal and sagittal planes, which was significantly smaller than that of all OARs ( Conclusions: Optical flow-guided analysis of intrafractional variations revealed that pancreatic tumors exhibited smaller ranges of motion than the adjacent OARs. These findings warrant direction-specific margins that account for intrafractional anatomic variations in both the tumors and surrounding OARs during pancreatic MRgART under abdominal compression.

Identifiers

PMID41799308
PMCPMC12962147

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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.