TTFields Plus FET-PET-Guided Stereotactic Radiosurgery Versus TTFields Alone for Recurrent Glioblastoma (Tarrget 2.0)

June 19, 2026 updated by: Maciej Harat, Prof. Franciszek Lukaszczyk Memorial Oncology Center

Tumor Treating Fields (TTFields) Concomitant With Stereotactic Radiosurgery Based on FET-PET vs TTFields Alone for the Treatment of Recurrent, Glioblastoma (Tarrget 2.0)

This study evaluates whether the addition of FET-PET-guided stereotactic radiosurgery (SRS) to Tumor Treating Fields (TTFields) improves survival outcomes in patients with recurrent IDH-wildtype glioblastoma.

Patients with recurrent glioblastoma have limited treatment options and poor prognosis. TTFields is a non-invasive antimitotic therapy that has demonstrated efficacy in recurrent glioblastoma. Stereotactic radiosurgery is commonly used in selected patients with recurrent disease; however, treatment efficacy may be limited by the infiltrative nature of glioblastoma and challenges in accurate target delineation.

The study hypothesizes that combining TTFields with FET-PET-guided stereotactic radiosurgery will improve one-year overall survival compared with TTFields alone. Participants will be randomized in a 1:1 ratio to receive either TTFields plus stereotactic radiosurgery or TTFields alone.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Glioblastoma is the most common malignant primary brain tumor in adults and remains associated with poor prognosis despite multimodal treatment. There is currently no established standard therapy for recurrent glioblastoma, and outcomes remain unsatisfactory.

Tumor Treating Fields (TTFields) are low-intensity, intermediate-frequency alternating electric fields that disrupt mitosis and inhibit tumor growth. TTFields have demonstrated efficacy in recurrent and newly diagnosed glioblastoma with minimal systemic toxicity.

Stereotactic radiosurgery (SRS) is an established local treatment option for selected patients with recurrent glioblastoma. However, MRI-based target delineation may underestimate the true extent of infiltrative tumor growth. FET-PET imaging provides improved visualization of metabolically active tumor tissue and may improve treatment precision.

Preclinical studies suggest synergistic effects between TTFields and radiation therapy through increased radiosensitivity and modulation of DNA repair mechanisms. Additional immunomodulatory effects may further enhance treatment efficacy.

This prospective randomized single-center study will compare TTFields combined with FET-PET-guided stereotactic radiosurgery versus TTFields alone in patients with recurrent IDH-wildtype glioblastoma. The primary objective is to determine whether combined treatment improves the one-year overall survival rate.

Study Type

Interventional

Enrollment (Estimated)

92

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 Locations

  • Poland
      • Bydgoszcz, Poland, 85-796
        • Recruiting
        • Department of Neurooncology and Radiosurgery, Franciszek Lukaszczyk Oncology Center

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age ≥18 years
  • Karnofsky Performance Status ≥70
  • Histologically confirmed IDH-wildtype glioblastoma
  • First, second, or third recurrence
  • Radiological recurrence according to RANO 2.0 criteria
  • Prior radiotherapy and temozolomide treatment
  • At least 6 months since completion of previous radiotherapy
  • Contrast-enhancing recurrent lesion visible on MRI
  • Maximum recurrent lesion diameter ≤5 cm
  • Available molecular profile including IDH and MGMT status
  • Adequate hematologic, renal, and hepatic function
  • Written informed consent

Exclusion Criteria:

  • Previous bevacizumab treatment
  • Planned chemotherapy or targeted therapy after study intervention
  • Previous stereotactic re-irradiation within the planned treatment field
  • More than three recurrences
  • Significant psychiatric disorders
  • Significant unrelated neurological disease
  • Implanted pacemaker, defibrillator, deep brain stimulator, or other incompatible electronic device
  • Pregnancy or breastfeeding
  • Active intracranial hemorrhage
  • Uncontrolled hypertension
  • Severe renal dysfunction
  • Participation in another interventional study likely to interfere with this 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: TTFields Plus FET-PET-Guided Stereotactic Radiosurgery
Participants receive Tumor Treating Fields (TTFields) therapy combined with FET-PET-guided stereotactic radiosurgery (SRS) for recurrent IDH-wildtype glioblastoma. TTFields treatment is administered for four months. Stereotactic radiosurgery is delivered within 14 days after initiation of TTFields according to protocol-defined target volumes based on MRI and FET-PET imaging.
Device: Tumor Treating Fields (TTFields)
Tumor Treating Fields (TTFields) therapy delivered using alternating electric fields through transducer arrays placed on the scalp. Treatment is administered continuously according to the study protocol for patients with recurrent IDH-wildtype glioblastoma.
Radiation: FET-PET-Guided Stereotactic Radiosurgery
Stereotactic radiosurgery planned using MRI and FET-PET imaging for treatment of recurrent IDH-wildtype glioblastoma. Radiosurgery is delivered within 14 days after initiation of TTFields according to protocol-defined target volumes.
Active Comparator: TTFields Alone
Participants receive Tumor Treating Fields (TTFields) therapy alone for recurrent IDH-wildtype glioblastoma according to standard clinical practice. TTFields treatment is administered for four months.
Device: Tumor Treating Fields (TTFields)
Tumor Treating Fields (TTFields) therapy delivered using alternating electric fields through transducer arrays placed on the scalp. Treatment is administered continuously according to the study protocol for patients with recurrent IDH-wildtype glioblastoma.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
One-Year Overall Survival Rate
Time Frame: 12 months after randomization
Proportion of participants alive 12 months after randomization
12 months after randomization

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Overall Survival (OS)
Time Frame: From randomization until death from any cause, up to 81 months
Overall survival is defined as the time from randomization to death from any cause. Participants who are alive at the time of analysis will be censored at the date of last contact. Median overall survival will be estimated using the Kaplan-Meier method.
From randomization until death from any cause, up to 81 months
Progression-Free Survival (PFS)
Time Frame: Up to 12 months after randomization
Progression-free survival is defined as the time from randomization to radiographic disease progression according to RANO 2.0 criteria or death from any cause, whichever occurs first. Participants without an event will be censored at the date of last disease assessment. Median, 6-month, and 12-month progression-free survival rates will be estimated.
Up to 12 months after randomization
Objective Response Rate (ORR)
Time Frame: Up to 12 months after randomization
Objective response rate is defined as the proportion of participants achieving a complete response (CR) or partial response (PR) according to RANO 2.0 criteria within 12 months after randomization. Best overall response will be determined using serial MRI assessments.
Up to 12 months after randomization
Radiation-Induced Contrast Enhancement (RICE)
Time Frame: Up to 12 months after randomization
Radiation-induced contrast enhancement is defined as new or increasing contrast enhancement observed on follow-up MRI that subsequently remains stable or resolves without evidence of tumor progression. The incidence of radiation-induced contrast enhancement (RICE) will be assessed and compared between study groups.
Up to 12 months after randomization
Treatment-Related Adverse Events
Time Frame: From randomization through 12 months after randomization
Treatment-related adverse events will be assessed and graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE), version 5.0. The proportion of participants experiencing grade 3 or higher treatment-related adverse events will be compared between treatment groups.
From randomization through 12 months after randomization
Patterns of Failure
Time Frame: Up to 12 months after randomization
Patterns of failure will be evaluated based on the location of disease progression relative to the baseline recurrent tumor volume identified on screening MRI and treatment planning imaging. Disease progression will be classified as local, marginal, or distant.
Up to 12 months after randomization
Molecular Predictors of overall survival
Time Frame: Up to 81 months after randomization
Associations between molecular tumor characteristics, including MGMT promoter methylation status and other available molecular markers, and treatment outcomes will be evaluated to identify potential predictors of overall survival
Up to 81 months after randomization
Corticosteroid Requirements
Time Frame: From randomization until disease progression, up to 12 months after randomization
Corticosteroid requirements will be assessed as the cumulative and daily corticosteroid dose administered from randomization until disease progression. Changes in corticosteroid use over time will be compared between treatment groups.
From randomization until disease progression, up to 12 months after randomization

Collaborators and Investigators

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

Sponsor

Prof. Franciszek Lukaszczyk Memorial Oncology Center

Collaborators

Medical Research Agency, Poland

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)

December 30, 2025

Primary Completion (Estimated)

June 1, 2030

Study Completion (Estimated)

June 1, 2032

Study Registration Dates

First Submitted

June 10, 2026

First Submitted That Met QC Criteria

June 19, 2026

First Posted (Actual)

June 25, 2026

Study Record Updates

Last Update Posted (Actual)

June 25, 2026

Last Update Submitted That Met QC Criteria

June 19, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Tarrget 2.0

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

Individual participant data that underlie the results reported in publications may be made available upon reasonable request to the Principal Investigator, following approval of a research proposal and execution of a data sharing agreement

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

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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