Magnetic Resonance-guided Adaptive Stereotactic Body Radiotherapy for Hepatic Metastases (MAESTRO)

March 6, 2026 updated by: Juergen Debus, University Hospital Heidelberg

Magnetic Resonance-guided Adaptive Stereotactic Body Radiotherapy for Hepatic Metastases - MAESTRO -

Stereotactic body radiotherapy (SBRT) is an established local treatment method for patients with hepatic oligometastases. Liver metastases often occur in close proximity to radiosensitive organs at risk (OARs). This limits the possibility to apply sufficiently high doses needed for optimal local control. MR-guided radiotherapy (MRgRT) is expected to hold potential to improve hepatic SBRT by offering superior soft-tissue contrast for enhanced target identification as well as the benefit of daily real-time adaptive treatment. The MAESTRO trial therefore aims to assess the potential advantages of adaptive, gated MR-guided SBRT (MRgSBRT) compared to conventional SBRT at a standard linac using an ITV (internal target volume) approach (ITV-SBRT).

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.

Detailed Description

Hepatic SBRT is a well-established local treatment method for technically or medically inoperable hepatic metastases. However, clinicians are often restricted in the utilization of hepatic SBRT due to dose limitations of the uninvolved liver and nearby OARs (e.g. small bowel, stomach, kidney). MR-guided radiotherapy with its superior soft-tissue contrast is believed to facilitate the precise detection of tumor position and interfractional changes in patient anatomy. Respiratory gating at the MR-Linac enables real-time visualization of the tumor as well as synchronization of beam delivery to the patient's breathing . Therefore, safety margins and thus the irradiated volume can possibly be decreased with MRgSBRT in comparison to ITV-based SBRT, reducing the risk of treatment-associated toxicity. Hepatic MRgSBRT of smaller target volumes might further offer the possibility of dose escalation for increasing local control. To our knowledge, only two retrospective analyses including 26 and 29 patients as well as one case report about hepatic MR-guided SBRT using a MR-Linac can be found in literature. As MR-guided adaptive SBRT is very staff intense and time consuming compared to standard ITV-based SBRT, prospective studies are needed to demonstrate the expected benefits of MR-guided adaptive SBRT. This trial will be conducted as a prospective, randomized, three-armed phase II study in 82 patients with hepatic metastases (solid malignant tumor, 1-3 hepatic metastases confirmed by magnetic resonance imaging (MRI), maximum diameter of each metastasis ≤ 5 cm (in case of 3 metastases: sum of diameters ≤ 12cm), age ≥ 18 years, Karnofsky Performance Score ≥ 60%). If a biologically effective dose (BED) ≥ 100 Gy is feasible based on ITV-based planning, patients will be randomized to either MRgSBRT (Arm A) or ITV-based SBRT (Arm B). If a lesion cannot be treated with a BED ≥ 100 Gy, the patient will be treated in Arm C with MRgSBRT at the highest possible dose.

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.
90

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.
  • Phase 2

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 Locations

  • Germany
      • Heidelberg, Germany, 69120
        • Recruiting
        • University Hospital of Heidelberg, Radiation Oncology
        • Principal Investigator:
          • Jürrgen Debus, MD PHD

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:

  • confirmed underlying solid malignant tumor (no germ cell tumor, leukemia, lymphoma)
  • 1-3 hepatic metastases confirmed by pre-therapeutic MRI
  • indication for SBRT of 1-3 hepatic metastases
  • maximum diameter each hepatic metastasis ≤ 5 cm (in case of 3 metastases: sum of diameters ≤ 12 cm)
  • age ≥ 18 years of age
  • Karnofsky Performance Score ≥ 60%
  • ability to lie still on the radiotherapy treatment couch for at least one hour
  • ability to hold one's breath for more than 25 seconds
  • for women with childbearing potential, adequate contraception
  • ability of subject to understand character and individual consequences of the clinical trial
  • written informed consent (must be available before enrolment in the trial)

Exclusion Criteria:

  • refusal of the patients to take part in the study
  • patients with primary liver cancer (eg. HCC, CCC)
  • patients after liver transplantation
  • impairment of liver function to an extent contraindicating radiotherapy (to the discretion of the treating radiation oncologist)
  • active acute hepatic/biliary infection (e.g. hepatitis, cholangitis, cholecystitis)
  • previous radiotherapy of the hepatobiliary system, if previous and current target volumes overlap MAESTRO Study Studienprotokoll Seite 25 von 54 Version 1.0 vom 17.12.2020
  • patients who have not yet recovered from acute toxicities of prior therapies
  • claustrophobia
  • pregnant or lactating women
  • contraindications against performing contrast-enhanced MRI scans (pacemakers, other implants making MRI impossible, allergy to gadolinium (GD)-based contrast agent)
  • participation in another competing clinical study or observation period of competing trials

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: A
Magnetic Resonance-guided Stereotactic Body Radiotherapy (MRgSBRT), if a biologically effective dose (BED) of ≥ 100 Gy is achievable using an ITV
Radiation: MRgSBRT (Magnetic Resonance-guided Stereotactic Body Radiotherapy)
MRgSBRT (Magnetic Resonance-guided Stereotactic Body Radiotherapy)
Experimental: B
ITV (Internal target volume)-based Stereotactic Body Radiotherapy (ITV-SBRT), if a biologically effective dose (BED) of ≥ 100 Gy is achievable using an ITV
Radiation: ITV (Internal target volume)-based Stereotactic Body Radiotherapy (ITV-SBRT)
ITV (Internal target volume)-based Stereotactic Body Radiotherapy (ITV-SBRT)
Experimental: C
Magnetic Resonance-guided Stereotactic Body Radiotherapy (MRgSBRT). If a BED of ≥ 100 Gy cannot be achieved using an ITV concept (e.g. due to OAR constraints), patients will be treated in arm C using MRgSBRT with the highest achievable dose as deemed appropriate by the treating radiation oncologist
Radiation: MRgSBRT (Magnetic Resonance-guided Stereotactic Body Radiotherapy)
MRgSBRT (Magnetic Resonance-guided Stereotactic Body Radiotherapy)

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
Treatment related Toxicity
Time Frame: within the first year after radiation treatment
occurrence of treatment-related gastrointestinal or hepatobiliary CTCAE V5.0 toxicity of grade III or higher
within the first year after radiation treatment

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
Treatment related Toxicity
Time Frame: within 24 months after radiation treatment
assesment of toxicity according to CTCAE V5.0 in all three treatment groups
within 24 months after radiation treatment
Treatment related Quality of life
Time Frame: within 24 months after radiation treatment
Changes in quality of life according to EORTC QLQ C-30
within 24 months after radiation treatment
Treatment related Quality of life
Time Frame: within 24 months after radiation treatment
Changes in quality of life according to EORTC QLQ LMC-21
within 24 months after radiation treatment
local Tumor Control
Time Frame: within 24 months after radiation treatment
Change of local Tumor size at one specific site
within 24 months after radiation treatment
locoregional control
Time Frame: within 24 months after radiation treatment
Change of local Tumor size within a defined local region
within 24 months after radiation treatment
distant tumor control
Time Frame: within 24 months after radiation treatment
apparence of distant Tumor leasions
within 24 months after radiation treatment
progression-free survival (PFS)
Time Frame: 24 months after radiation treatment
time of suvival without Tumor progression
24 months after radiation treatment
overall survival (OS)
Time Frame: 24 months after radiation treatment
time of Survival of studypopulation
24 months after radiation treatment
Changes in applied biological effective doses (BED) to the target Volumen (Tumor)
Time Frame: through study completion, an average of 1 year
BED increase and OAR doses with MRgSBRT compared to initial ITV-based planning in arms A and C
through study completion, an average of 1 year
Evaluation of potential prognostic biomarkers
Time Frame: within 24 months after radiation treatment
Changes in blood Levels of blood Parameters compared to reference samples
within 24 months after radiation treatment

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

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.
August 12, 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.
January 31, 2029

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 31, 2030

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).
August 3, 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.
August 25, 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.
August 30, 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.
March 10, 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.
March 6, 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.
March 1, 2026

More Information

Terms related to this study

Keywords

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.
  • RADONK-MAESTRO-2020

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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