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

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
326

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Germany
      • Heidelberg, Germany
        • Recruiting
        • Universitatsklinikum 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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Hospital Heidelberg

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • 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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 19, 2021

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 19, 2030

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 19, 2033

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 9, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 11, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 12, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 21, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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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