Glioblastoma Radiotherapy Using IMRT or Proton Beams (GRIPS)

May 21, 2026 updated by: Juergen Debus, University Hospital Heidelberg
Radiation therapy is an integral part of the multimodal primary therapy of glioblastomas. As the overall prognosis in this tumor entity remains unfavorable, current research is focused on additional drug therapies, which are often accompanied by increases in toxicity. By using proton beams instead of photon beams, it is possible to protect large parts of the brain which are not affected by the tumor more effectively. An initial retrospective matched-pair analysis showed that this theoretical physical benefit is also clinically associated with a reduction in toxicity during therapy and in the first few months thereafter. The aim of the GRIPS study is to prospectively test this clinical benefit in a randomized, open-label Phase III study. Patients are treated in the study using either modern photon radiation techniques (standard arm) or proton beams (experimental arm). The primary endpoint is the cumulative toxicity CTC grade 2 and higher in the first 4 months. Secondary endpoints include overall survival, progression-free survival, quality of life, and neurocognition.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

326

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Germany
      • Heidelberg, Germany
        • Recruiting
        • Universitätsklinikum Heidelberg
        • Contact:
          • Klaus Herfarth, Prof. Dr.
      • Marburg, Germany
        • Not yet recruiting
        • Universitätsklinikum Gießen und Marburg
        • Contact:
          • Rita Engenhart-Cabillic, Prof. Dr.
      • Stuttgart, Germany
        • Not yet recruiting
        • Klinikum Stuttgart
        • Contact:
          • Marc Münter, Prof. Dr.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • histologically confirmed gliomblastoma WHO IV (operated or after biopsy)
  • Indication for radiotherapy / radiochemotherapy
  • Informed consent
  • KI ≥ 60% or ECOG 0/1
  • Age ≥ 18 years
  • Sufficient effective contraception

Exclusion Criteria:

  • Patient is not able to consent
  • Previous radiotherapy in the brain or skull base
  • Active medical implants for which there is no ion radiation authorization at the time of treatment (e.g., cardiac pacemaker, defibrillator, ...)
  • Contraindication to MRI imaging
  • Simultaneous participation in another clinical trial that could influence the outcome of this study or other study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Arm A: Proton irradiation
Irradiation applied with protons
Radiation: Proton irradiation
proton irradiation applied as follows: 30 x 2 Gy(RBE) 33 x 1,8 Gy (RBE), or 15 x 2,67 Gy (RBE)
Active Comparator: Arm B: Photon IMRT
Photon irradiation applied as intensity-modulated radiotherapy
Radiation: Photon irradiation
proton irradiation applied as follows: 30 x 2 Gy 33 x 1,8 Gy, or 15 x 2,67 Gy

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cumulative rate of toxicity
Time Frame: from start of radiotherapy until progress (max. month 4)
Cumulative rate of toxicity ≥ grade 2 (until progress (max. month 4))
from start of radiotherapy until progress (max. month 4)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Progression free survival
Time Frame: 1 year and 2 years
Progression free survival
1 year and 2 years
Overall survival
Time Frame: 1 year and 2 years
Overall survival
1 year and 2 years
Acute Toxicity
Time Frame: start of therapy until 6 weeks after end of therapy (end of therapy up to month 4)
according to CTC AE V5.0
start of therapy until 6 weeks after end of therapy (end of therapy up to month 4)
Late Toxicity
Time Frame: 6 weeks after end of therapy (end of therapy up to month 4)
according to CTC AE V5.0
6 weeks after end of therapy (end of therapy up to month 4)
Quality of life according to EORTC QLQ-C30
Time Frame: 1 year and 2 years
according to EORTC QLQ-C30
1 year and 2 years
Quality of life according to EORTC QLQ-BN20
Time Frame: 1 year and 2 years
according to EORTC QLQ-BN20
1 year and 2 years
Neurocognition
Time Frame: 1 year and 2 years
according to Hopkins Verbal Learning Test-Revised
1 year and 2 years
Measuring number of Lymphocytes count
Time Frame: end of therapy up to month 4
end of therapy up to month 4

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital Heidelberg

Investigators

  • Principal Investigator: Laila König, Prof. Dr., University Hospital of Heidelberg, Radiation Oncology

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 19, 2021

Primary Completion (Estimated)

September 19, 2030

Study Completion (Estimated)

January 19, 2033

Study Registration Dates

First Submitted

February 9, 2021

First Submitted That Met QC Criteria

February 11, 2021

First Posted (Actual)

February 12, 2021

Study Record Updates

Last Update Posted (Actual)

May 27, 2026

Last Update Submitted That Met QC Criteria

May 21, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • GRIPS

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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