Evidence map›Paper›PMID 42819047›Full record

ArticleFrontiers in oncology2026

Case Report: Acute prostatic swelling following hydrogel spacer insertion managed by MR-guided online adaptive radiotherapy.

Yushi Takahashi, Noriyoshi Takahashi, Sakiko Kageyama, Shohei Tanaka, Rei Umezawa, Takaya Yamamoto, Yu Suzuki, Keita Kishida, So Omata, Keiichi Jingu

Abstract readCase Reports
In one paragraph

Article in Frontiers in 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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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

10 authors.

Yushi TakahashiDepartment of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Noriyoshi TakahashiDepartment of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Sakiko KageyamaDepartment of Diagnostic Radiology, Tohoku University Hospital, Sendai, Japan.
Shohei TanakaDepartment of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Rei UmezawaDepartment of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Takaya YamamotoDepartment of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Yu SuzukiDepartment of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Keita KishidaDepartment of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
So OmataDepartment of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Keiichi JinguDepartment of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Hydrogel spacers are widely used in radiotherapy for localized prostate cancer to reduce the rectal dose. While generally safe, acute anatomical changes in the prostate gland itself, specifically significant swelling, are poorly described and can compromise the precision of radiotherapy. Case presentation: We report a case of a 62-year-old man with high-risk prostate cancer (PSA 15.9 ng/mL, Gleason score 4 + 4, cT2cN0M0) who underwent hydrogel spacer placement for stereotactic body radiotherapy (SBRT) (40 Gy in 5 fractions). Although magnetic resonance imaging (MRI) for radiation planning on day 8 postinsertion revealed a normal prostate volume (22.0 cc), pretreatment MRI for MR-guided online adaptive radiotherapy (MRgOART) on day 23 (at the second fraction) revealed a peak volume of 31.4 cc, a 42.7% increase. This swelling compromised the dosimetry of the initial plan, risking insufficient coverage of the clinical target volume (CTV). Using MRgOART, the plan was successfully reoptimized to prevent target underdosing. Conclusions: We report a rare instance of acute prostate swelling following hydrogel spacer insertion. Although the precise etiology remains unconfirmed, such an anatomical change, if unrecognized, could degrade treatment accuracy. This case demonstrates that online adaptive radiotherapy via an MR-Linac is essential for detecting and managing unexpected anatomical variations during prostate SBRT.

Indexed as

case reporthydrogel spacerMR-guided adaptive radiotherapyprostate cancerprostate swellingstereotactic body radiotherapy

Identifiers

PMID42819047
PMCPMC13623546

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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.