Leica Microsystems Sponsored PMCF Study to Collect and Confirm Clinical Data on the Performance of the GLOW400 Device When Used in Accordance With Its Intended Use (IMED-GLOW400)

Fluorescence Visualization and Image Quality Evaluation of Digital Visualization of Suspected Grade III and/or IV Gliomas During Neurosurgery (Leica GLOW400)

This post-market clinical follow-up (PMCF) study aims to confirm the safety and performance of the GLOW400 surgical microscope accessory when used in conjunction with the ARveo8x surgical microscope. The study evaluates fluorescence visualization and image quality during standard surgical procedures in neurosurgery. It is a non-interventional, observational study conducted in routine care settings across multiple European sites.

Study Overview

• Status: Not yet recruiting
• Conditions: Glioma; Glioblastoma (GBM); Suspected Grade III and IV Gliomas Requiring Surgical Intervention; Neurosurgical Procedure
• Intervention / Treatment: Device: GLOW400 is a digital surgical microscope accessory used in fluorescent visualization of suspected grade III or IV gliomas during neurosurgery.

Detailed Description

The IMED-GLOW400 study is a prospective, observational, non-interventional clinical investigation conducted in the European Economic Area and Switzerland. It involves the use of the GLOW400 accessory, which digitally enhances fluorescence signals during neurosurgery, providing improved anatomical visualization and contrast. The study compares GLOW400 with the benchmark FL400 optical filter system.

The primary objective is to confirm the image quality and fluorescence visualization performance of GLOW400. Secondary objectives include validating product claims and assessing user experience and safety. An exploratory objective evaluates the extent of tumor resection using volumetric analysis of pre- and post-operative MRI scans.

Data will be collected through structured questionnaires, histopathology confirmation, optional resection forms, and intraoperative video recordings. The study will enroll 37 patients, with at least 29 complete datasets required for analysis. The duration of the study is estimated at 5 to 6 months, with each patient participating only during the surgical procedure.

The study complies with ISO 14155:2020, GDPR, and the Declaration of Helsinki. Ethics Committee approval and informed consent are mandatory prior to enrollment. No additional procedures beyond standard of care are introduced, and risks are limited to those associated with routine surgical practice.

• Study Type: Observational
• Enrollment (Estimated): 37

Contacts and Locations

• Study Contact: Name: Daniela Leal; Phone Number: +41793741989; Email: daniela.leal@leica-microsystems.com

Study Locations

• Portugal
  • Porto, Portugal
    • Unidade Local de Saúde de São João
    • Contact: Pedro Alberto Guzman, MD PhD FEBNS; Phone Number: +351 933 205 202; Email: pa.silva@ulssjoao.min-saude.pt
• Switzerland
  • Basel, Switzerland
    • University Hospital Basel
    • Contact: Raphael Guzman, Prof. med.; Phone Number: +41 61 265 33 68; Email: raphael.guzman@usb.ch

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Patient population will include patients with suspected grade III or IV gliomas requiring surgical intervention, and who meet the Inclusion/Exclusion Criteria for the IMED-GLOW400 Study.

Description

Candidates for the for the IMED-GLOW400 Study must be appropriate patients for surgical interventions with suspected intracranial high-grade glioma evidenced by preoperative imaging modalities and have to fulfil all of the following inclusion criteria to be eligible for the recruitment of the study.

Inclusion Criteria

1. Participants must be 18 years of age or older at the time of signing the informed consent.
2. Participants must have suspected high-grade glioma (WHO grade III-IV) as evidenced by preoperative imaging modalities, which require surgical intervention.
3. The active substance 5-aminolevulinic acid (5-ALA) fluorescence dye is administered according to the 5-ALA instructions for use.
4. The participant or their legal representative must understand the study and have voluntarily signed and dated the Informed Consent Form, which has been approved by the Sponsor and the Ethics Committee for this study.

Note for Switzerland only:

Enrollment via legal representative is not permitted. Therefore, only patients who are capable of providing informed consent themselves will be eligible for inclusion in Switzerland.

Exclusion Criteria

1. Known allergy to 5-ALA hydrochloride or protoporphyrin.
2. Patients with porphyria (a condition characterized by the inability to break down protoporphyrin).
3. Any uncontrolled systemic condition that may adversely affect the surgical outcome.
4. Patients holding United States citizenship.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

GLOW400

Device: GLOW400 is a digital surgical microscope accessory used in fluorescent visualization of suspected grade III or IV gliomas during neurosurgery.; The digital surgical microscope accessory GLOW400 is using the optical excitation and emission filtering of the FL400. The FL400 provides an illumination filter (380nm - 430nm) which when engaged into the light source path of the surgical operating microscope provides, via a light guide, a fluorescence excitation light system used in conjunction with an approved tumor-selective substance (fluorophore) (e.g. Protoporphyrin IX (PpIX) which is resulting of the metabolization of 5-ALA (5 - aminolaevulinic acid)) for tissue characterization in the open neurosurgery field. PpIX is strongly fluorescent with a peak at λ=635 nm as red-violet after excitation with blue light (λ=380-410 nm). The digital surgical microscope accessory GLOW400 is using the optical excitation and emission filtering of the FL400. The fluorescence signal visualized depicts the distribution of the dye in the patient's tissues during the surgical procedure.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Flourescence visibility	Performance will be evaluated using Questionnaire, a structured Likert-scale survey completed by the operating surgeon during and after surgery. The questionnaire assesses: perceived intensity of fluorescence; perceived volume/ shape and relative location; perceived distribution of fluorescence; anatomical and fluorescence observation (GLOW400 Anatomy only) Each item is rated on a 5-point Likert scale: = Not available; = Insufficient; = Sufficient; = Very good; = Excellent Higher scores indicate better performance. The outcome is considered acceptable if all ratings are ≥3 (Sufficient or better).	Periprocedural
Image quality	Performance will be evaluated using Questionnaire, a structured Likert-scale survey completed by the operating surgeon during and after surgery. The questionnaire assesses:: Stereoscopic Perception (3D Depth perception); Resolution; Noise; Latency Each item is rated on a 5-point Likert scale: = Not available; = Insufficient; = Sufficient; = Very good; = Excellent Higher scores indicate better performance. The outcome is considered acceptable if all ratings are ≥3 (Sufficient or better).	Periprocedural
Anatomy of the brain, including Vessels (GLOW400 Anatomy only)	Performance will be evaluated using Questionnaire, a structured Likert-scale survey completed by the operating surgeon during and after surgery. The questionnaire assesses: Neuroanatomy structures; Vascular structures 4. Perceived contrast (GLOW400 HiFluo only) 5. Bleeding visibility (GLOW400 Anatomy only) 6. Traces of remaining fluorescence (GLOW400 HiFluo only) Each item is rated on a 5-point Likert scale: = Not available; = Insufficient; = Sufficient; = Very good; = Excellent Higher scores indicate better performance. The outcome is considered acceptable if all ratings are ≥3 (Sufficient or better).	Periprocedural

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The secondary objectives of this Post-Market Clinical Follow-up (PMCF) study are to assess the continued safety of the device.	Safety will be evaluated using Questionnaire B, completed postoperatively by the surgical team. It captures: Dizziness through using digital 3D visualization; Delayed, interrupted or hindered surgery due to different causes; Occurred injuries to the patient; Breach of sterility; Any patient or user tissue burn event reported.; Confirm user experience with the use of the device in real clinical practice, supporting the marketing claims:Confidence in decisionFocus during procedureSurgical course of actionUser experienceMental fatigue Responses are binary: = Yes (event occurred); = No (event did not occur) Lower scores (2 = No) indicate better safety outcomes. The outcome is acceptable if no safety events are reported.	Postoperatively

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of the extent of tumor resection	The extent of tumor resection will be evaluated using volumetric analysis. The volumetric measurement will be carried out by a neuroradiologist. Precise three-dimensional (3D) rendering and analysis of pre-operative and post-operative MRI images, facilitating accurate assessment of residual tumor volume. Radiology reports include: • Residual tumor percentage %. Based on the residual tumor percentage, the appropriate category will be selected (4): Complete tumor resection: (100% + 0 cm3 CE); Near total resection: (≥ 95% + ≤ 1 cm3 CE); Subtotal resection: (≥ 80% + ≤ 5 cm3 CE); Partial resection: (< 80% ± >5 cm3 CE)	Postoperatively

Collaborators and Investigators

• Sponsor: Leica Microsystems (Schweiz) AG

Study record dates

Study Major Dates

• Study Start (Estimated): February 1, 2026
• Primary Completion (Estimated): December 20, 2026
• Study Completion (Estimated): May 31, 2027

Study Registration Dates

• First Submitted: January 7, 2026
• First Submitted That Met QC Criteria: January 16, 2026
• First Posted (Actual): January 26, 2026

Study Record Updates

• Last Update Posted (Actual): January 26, 2026
• Last Update Submitted That Met QC Criteria: January 16, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: High-grade glioma; fluorescence-guided surgery; GLOW400; Image quality assessment; ARveo8x; Digital surgical microscope; 5-ALA fluorescence; Grade III gliomas; Grade IV gliomas
• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Astrocytoma; Neoplasms, Neuroepithelial; Neuroectodermal Tumors; Neoplasms, Germ Cell and Embryonal; Neoplasms, Nerve Tissue; Glioblastoma; Glioma
• Other Study ID Numbers: GLOW400-PMCFSTUDYPLAN-202501

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: IPD used in the results publication.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; CSR

Drug and device information, study documents

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