Evidence map›Paper›PMID 40624549›Full record

ArticleBMC urology2025

Evaluation of the changes in hydrogel spacer volume in patients treated with proton therapy for prostate cancer.

Kuniaki Inoue, Masatake Shinohara, Toshihisa Saka, Yoshihiko Hirao, Yasuhiro Shinohara, Tatsuyuki Higashikawa, Michinori Yamamoto

Erratum issuedAbstract read
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In one paragraph

Article in BMC urology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

7 authors.

Kuniaki InoueDepartment of Urology, Osaka Gyoumeikan Hospital, 5-5-8 Nishikujo, Osaka konohana-ku, Osaka, 554-0012, Japan.
Masatake ShinoharaDepartment of Urology, Osaka Gyoumeikan Hospital, 5-5-8 Nishikujo, Osaka konohana-ku, Osaka, 554-0012, Japan. bonyarishinohara@hotmail.co.jp.
Toshihisa SakaDepartment of Urology, Osaka Gyoumeikan Hospital, 5-5-8 Nishikujo, Osaka konohana-ku, Osaka, 554-0012, Japan.
Yoshihiko HiraoDepartment of Urology, Osaka Gyoumeikan Hospital, 5-5-8 Nishikujo, Osaka konohana-ku, Osaka, 554-0012, Japan.
Yasuhiro ShinoharaDepartment of Radiology, Osaka Proton Therapy Clinic, 1-27-9 Kasugade naka, Osaka konohana-ku, Osaka, 554-0022, Japan.
Tatsuyuki HigashikawaDepartment of Radiology, Osaka Proton Therapy Clinic, 1-27-9 Kasugade naka, Osaka konohana-ku, Osaka, 554-0022, Japan.
Michinori YamamotoDepartment of Radiology, Osaka Proton Therapy Clinic, 1-27-9 Kasugade naka, Osaka konohana-ku, Osaka, 554-0022, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundRectal bleeding is a recognized late complication of radiation therapy in the treatment of prostate cancer, and hydrogel spacers have been used to prevent this adverse effect. Previous reports have indicated that the volume of hydrogel spacers remains stable for at least 3 months after implantation [1]; however, no cases of early resolution have been reported. Therefore, this study aimed to investigate the hydrogel spacer volume changes over time.

methodsWe included 103 patients implanted with hydrogel spacers who underwent proton therapy at our hospital between April 2020 and November 2022. Two patients were excluded due to improper hydrogel spacer placement beyond the prostatic side of Denonvilliers' fascia. To examine the volume of Space OAR, we measured the spacer volume using magnetic resonance imaging at the time of dosimetry treatment planning and again at 7 and 21 fractions in the remaining 101 patients.

resultsAmong the 101 patients, four exhibited a significant reduction in spacer volume at 21 fractions, and one of these patients experienced rectal bleeding.

conclusionUnexpected early changes in the hydrogel spacer volume may increase rectal exposure from the time of radiation planning. CLINICAL TRIAL NUMBER: Not applicable.

Indexed as

Gastrointestinal HemorrhageHydrogelsProstatic NeoplasmsProton TherapyRadiation InjuriesAgedAged, 80 and overHumansMaleMiddle AgedRectumRetrospective StudiesHydrogelsHydrogel spacerProstate cancerProton therapyRectal bleedingVolume change

Identifiers

PMID40624549
PMCPMC12232674

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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.