Clinical Significance of Liquid Biopsy in Brain Tumor Patients: a 5-ALA Guided Approach (FLUO-LB)

Glioblastoma (GBM) is the most common and lethal primary brain tumor. Identifying blood biomarkers that reflect the tumor's status is a major unmet need for optimal clinical management. 5-ALA (5-Aminolevulinic Acid) administration leads to the accumulation of fluorescent Protoporphyrin IX (PpIX) in GBM cells, allowing identification during surgery. This project aims to leverage 5-ALA induced fluorescence to maximize the informational power of plasma liquid biopsy as a tool for diagnosis, post-treatment follow-up, and as a prognostic tool in patients with GBM.

Study Overview

• Status: Recruiting
• Conditions: Glioblastoma; Glioblastoma - Category; Glioblastoma (GBM); Brain Tumors and/or Solid Tumors Including

Detailed Description

This is a prospective observational study. Patients with suspected brain tumors requiring 5-ALA fluorescence-guided surgery will be enrolled. Samples of plasma, serum, and urine will be collected at a minimum of two timepoints: once before 5-ALA administration (baseline, T1) and again 12 hours after administration (T2), when PpIX levels are expected to be highest. All sample collection and processing will occur in low-light conditions to prevent PpIX degradation. Samples will be stored at -80°C. Fluorometric analysis (Perkin Elmer Wallac 1420 Victor2 Microplate Reader) will be performed to measure PpIX fluorescence. Additionally, each patient will undergo a pre-operative MRI as per routine care to measure tumor volume, which will be correlated with fluorescence data.

• Study Type: Observational
• Enrollment (Estimated): 30

Contacts and Locations

• Study Contact: Name: Francesco Di Meco, MD; Phone Number: + 39 02.2394; Email: francesco.dimeco@istituto-besta.it

Study Locations

• Italy
  • Milan, Italy
    • Recruiting
    • Fondazione IRCCS Istituto Neurologico Carlo Besta
    • Contact: Francesco Di Meco, MD; Phone Number: +39 02 2394; Email: francesco.dimeco@istituto-besta.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

30 Patients with brain tumors whose treatment course involves fluorescence-guided surgery 5-ALA.

Description

Inclusion Criteria:

• Inclusion Criteria (Glioblastoma Patients):
• Patient aged 18 years or older
• Diagnosis of supratentorial glioblastoma at its first occurrence (Grade 4, WHO 2021), confirmed through histological analysis, in a brain area that is accessible for surgical removal.
• Ability of the patient to give informed consent.
• Suitability for surgery with fluorescence guidance using 5-ALA.

Inclusion Criteria (Other Brain Tumors):

• Patient aged 18 years or older
• Ability of the patient to give informed consent.
• Suitability for surgery with fluorescence guidance using 5-ALA.

Exclusion Criteria:

Exclusion Criteria (Glioblastoma Patients):

• Presence of other systemic tumors.
• Known allergic sensitivity or contraindications to gadolinium.
• Contraindications to MRI, such as the presence of non-compatible implanted devices.
• Significantly compromised renal function (eGFR <30 ml/min/1.73 m²), and/or patients undergoing dialysis.
• Conditions that contraindicate surgery with fluorescence guidance using 5-ALA.

Exclusion Criteria (Other Brain Tumors):

• Patients suffering from systemic tumors (besides the primary of the brain metastasis).
• Individuals with known allergies or adverse reactions to gadolinium.
• Individuals with contraindications for MRI, including those with implants not compatible with the procedure.
• Individuals with significantly reduced kidney function (eGFR < 30 ml/min/1.73 m²), or those undergoing dialysis.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Glioblastoma Patients; Patients aged 18 or older with a first diagnosis of supratentorial glioblastoma (WHO Grade 4), confirmed by histology, who are candidates for 5-ALA fluorescence-guided surgery.
Other Brain Tumor Patients; Patients aged 18 or older with other brain tumors (in differential diagnosis with glioblastoma) who are candidates for 5-ALA fluorescence-guided surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Protoporphyrin IX (PpIX) Fluorescence Level in Glioblastoma Patients	PpIX fluorescence level in blood (serum and plasma) and urine at different time-points (pre-administration, 12h post-administration, and potentially other timepoints depending on preliminary observations) in patients with glioblastoma.	2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PpIX Fluorescence Level in Control/Other Brain Tumor Patients	PpIX fluorescence level in blood (serum and plasma) and urine at different time-points in controls/patients with other brain tumor pathologies.	2 years
Correlation of Fluorescence with Histopathological Characteristics	Correlation of PpIX fluorescence levels with histopathological characteristics of the tumor tissue.	2 years
Correlation of Fluorescence with Tumor Tissue Fluorescence	Correlation of PpIX fluorescence levels in liquid biopsy (blood/urine) with the observed fluorescence of the tumor tissue during surgery	2 years
Correlation of Fluorescence with MRI Lesion Volumes	Correlation of PpIX fluorescence levels with lesion volumes measured on pre-operative Magnetic Resonance Imaging (MRI).	2 years
Kinetics of 5-ALA-induced Fluorescence	Describe the kinetics (changes over time) of 5-ALA-induced fluorescence in plasma and urine levels.	2 years

Collaborators and Investigators

• Sponsor: Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta
• Collaborators: University of Milan; Università degli Studi del Piemonte Orientale Amedeo Avogadro

Study record dates

Study Major Dates

• Study Start (Actual): January 18, 2017
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: December 2, 2025
• First Submitted That Met QC Criteria: February 11, 2026
• First Posted (Actual): February 19, 2026

Study Record Updates

• Last Update Posted (Actual): February 19, 2026
• Last Update Submitted That Met QC Criteria: February 11, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: GBM; 5-ALA; Glioblastoma; Liquid Biopsy; Fluorescence; Glioblastoma (GBM); Protoporphyrin IX (PpIX)
• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Astrocytoma; Glioma; Neoplasms, Neuroepithelial; Neuroectodermal Tumors; Neoplasms, Germ Cell and Embryonal; Neoplasms, Nerve Tissue; Glioblastoma
• Other Study ID Numbers: FLUO-LB

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The Sponsor (Fondazione IRCCS Istituto Neurologico Carlo Besta) is the owner of the data resulting from the study. All Investigators participating in the study should be made aware of such circumstance and not to disseminate information or data without the prior written consent by the Sponsor

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No