Evidence map›Paper›PMID 42732307›Full record

ArticleBrain & spine2026

Short communication: Fluorescence preservation of protoporphyrin IX in fresh frozen glioma tissue.

Matthias Demetz, Kevin Buckley, Alexander Miller-Michlits, Yelyzaveta Miller-Michlits, Aleksandrs Krigers, Johannes Kerschbaumer, Claudius Thomé, Adelheid Wöhrer, Christian F Freyschlag

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Article in Brain & spine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Matthias DemetzDepartment of Neurosurgery, Medical University of Innsbruck, Innsbruck, Austria.
Kevin BuckleyStryker Innovation Centre, Co. Cork, Carrigtwohill, Ireland.
Alexander Miller-MichlitsInstitute of Neuropathology & Neuromolecular Pathology, Medical University of Innsbruck, Innsbruck, Austria.
Yelyzaveta Miller-MichlitsInstitute of Neuropathology & Neuromolecular Pathology, Medical University of Innsbruck, Innsbruck, Austria.
Aleksandrs KrigersDepartment of Neurosurgery, Medical University of Innsbruck, Innsbruck, Austria.
Johannes KerschbaumerDepartment of Neurosurgery, Medical University of Innsbruck, Innsbruck, Austria.
Claudius ThoméDepartment of Neurosurgery, Medical University of Innsbruck, Innsbruck, Austria.
Adelheid WöhrerInstitute of Neuropathology & Neuromolecular Pathology, Medical University of Innsbruck, Innsbruck, Austria.
Christian F FreyschlagDepartment of Neurosurgery, Medical University of Innsbruck, Innsbruck, Austria.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Introduction: 5-ALA-guided fluorescence surgery is widely used in glioma surgery to improve tumor visualization and extent of resection. However, it remains unknown whether Protoporphyrin IX (PpIX) fluorescence persists in fresh frozen tumor tissue and can be reliably detected after thawing. Research question: This study investigates whether PpIX fluorescence remains detectable in fresh frozen glioma tissue and compares the sensitivity of conventional surgical microscopy with a spectroscopic detection method. Material and methods: In this prospective study, 5-ALA-positive and -negative glioma tissue samples were collected intraoperatively, snap-frozen, and stored in a biobank. After thawing, samples were analyzed using both a conventional surgical microscope and a novel spectroscopic prototype. Histopathological confirmation was performed using H&E staining. Fluorescence detection rates were compared between methods. Results: A total of 46 samples were analyzed. Conventional microscopy failed to detect fluorescence in all thawed samples. In contrast, spectroscopic analysis identified PpIX fluorescence in all previously 5-ALA-positive samples, while negative controls showed no signal. Fluorescence detectability was independent of storage duration (5-14 months). These findings indicate that PpIX remains stable in frozen tissue. Discussion and conclusion: PpIX fluorescence persists in fresh frozen glioma tissue and can be reliably detected using sensitive spectroscopic techniques, whereas conventional microscopy is insufficient post-thaw. These results validate the use of biobanked 5-ALA-positive samples for downstream molecular analyses and highlight the importance of advanced detection methods for studying subvisual fluorescence.

Indexed as

5-ALA fluorescenceGlioblastomaProtoporphyrin IXSpectroscopic detection

Identifiers

PMID42732307
PMCPMC13570307

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.