Evidence map›Paper›PMID 42290893›Full record

ArticleClinical and translational radiation oncology2026

Safety and early organ preservation outcomes after dose escalation with MR-guided radiotherapy for rectal cancer (preRADAR): A phase I trial.

H Eijkelenkamp, M E Verweij, G Grimbergen, M Tanaka, C M Kensen, T Janssen, T Vijlbrief, W M U van Grevenstein, L M G Moons, M Koopman and 12 more

Abstract read
In one paragraph

Article in Clinical and translational radiation oncology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing 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

2 citing papers in PubMed.

  1. Article
  2. Article
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

22 authors.

H EijkelenkampDepartment of Radiation-Oncology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.
M E VerweijDepartment of Radiation-Oncology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.
G GrimbergenDepartment of Radiation-Oncology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.
M TanakaDepartment of Radiation-Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands.
C M KensenDepartment of Radiation-Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands.
T JanssenDepartment of Radiation-Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands.
T VijlbriefDepartment of Radiation-Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands.
W M U van GrevensteinDepartment of Surgery, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.
L M G MoonsDepartment of Gastroenterology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.
M KoopmanDepartment of Medical Oncology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.
M M LacleDepartment of Pathology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.
M N G J A BraatDepartment of Radiology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.
M MaasDepartment of Radiology, Netherlands Cancer Institute, Amsterdam, the Netherlands.
E C J ConstenDepartment of Surgery, Meander Medical Centre, Amersfoort, the Netherlands.
A PronkDepartment of Surgery, Diakonessenhuis Utrecht Zeist Doorn, Utrecht, the Netherlands.
A B SmitsDepartment of Surgery, Sint Antonius Hospital, Nieuwegein, the Netherlands.
J T HeikensDepartment of Surgery, Hospital Rivierenland, Tiel, the Netherlands.
S G EliasDepartment of Epidemiology & Health Economics, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
H M VerkooijenDivision of Imaging and Oncology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
G J MeijerDepartment of Radiation-Oncology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.
A CouwenbergDepartment of Radiation-Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands.
M P W IntvenDepartment of Radiation-Oncology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background and purpose: Organ preservation is a desirable goal for patients with rectal cancer. Magnetic resonance-guided radiotherapy (MRgRT) enables precise dose delivery and online adaptation. This phase I study (preRADAR) evaluated maximum tolerated dose (MTD) of short course radiotherapy (SCRT; 5x5 Gy) with a subsequent boost using MRgRT in intermediate-risk rectal cancer. Materials and methods: the trial had a 6 + 3 dose-escalation design. Patients staged T3c-d(MRF-)N0M0 or T1-3(MRF-)N1M0 were treated on a 1.5 Tesla MR-linac with short-course radiotherapy (SCRT; 5 × 5 Gy) followed by 2-4 daily 5 Gy GTV boosts according to the dose level. Safety was assessed by incidence of acute and perioperative dose-limiting toxicities (DLTs) within prespecified time windows and stopping boundaries. Secondary endpoints included technical feasibility (boost PTV V95% > 90%) and organ preservation at six months. Results: Out of 31 patients screened, sixteen were treated across three dose levels. All fractions were delivered as planned and all adaptive boost fractions achieved the predefined feasibility criterion (PTV V95% >90%). No acute DLTs occurred. Three perioperative DLTs were observed, including two anastomotic leaks requiring reoperation. The MTD was not identified; dose level 2 (SCRT + 4 × 5 Gy boosts) was the highest dose level completed within the DLT stopping boundaries, achieving a 26-week organ preservation rate of 56% (5/9). Conclusion: MRgRT-based enables dose escalation following SCRT in intermediate-risk rectal cancer. The highest evaluated dose level, 4 × 5 Gy GTV boosts after SCRT, was considered safe within the predefined DLT boundaries and feasible for further evaluation.

Indexed as

Dose escalation after short-course radiotherapyMR-guided radiotherapyOrgan preservationPhase I on safety and feasibilityRectal cancer

Identifiers

PMID42290893
PMCPMC13263622

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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.