# Neurosurgical and neuro-oncological outcomes of confirmatory brain biopsies in patients with glioblastoma: a real-life monocentric experience

## TL;DR

This study examines the outcomes of brain biopsies in patients with unresectable glioblastoma, finding high complication rates and limited access to further treatment.

## Contribution

The paper provides real-life data on the risks and outcomes of confirmatory brain biopsies for glioblastoma patients.

## Key findings

- Biopsied GB patients had an 11% complication rate and a median survival of 4.7 months.
- About 40% of patients did not access subsequent oncological treatments after biopsy.
- Unmethylated MGMT status and tumor proximity to the internal capsule were identified as risk factors.

## Abstract

Glioblastoma (GB) is an uncurable tumor with poor prognosis despite resection plus adjuvant cares. When unresectable, even in case of a clear radiological imaging, guidelines require a formal histological diagnosis to confirm the diagnosis of GB.

This study aims to assess the post-surgical complications and neuro-oncological outcomes of patients undergoing a confirmatory brain biopsy for diagnosing GB.

We considered 125 adult patients who underwent stereotactic biopsy between January 2018 and December 2023 at the Neurosurgery Department of IRCCS San Gerardo dei Tintori. Among them, 74 patients with radiological diagnosis of GB underwent a purely confirmatory biopsy. The clinical history of each patient was evaluated from the onset of symptoms through subsequent neuro-oncological treatments. We evaluated the patients' clinical conditions at the time of biopsy and upon discharge, the radiological characteristics of the tumor, the histopathological diagnosis, biopsy-related complications, access to oncological treatments along with associated complications and neurological-functional outcomes.

Unmethylated MGMT status, KPS≤70, tumor proximity to the internal capsule and absence of motor hemisyndrome at symptoms onset emerged as possible risk factors. Biopsied GB patients had an 11% complication rate and exhibited a dismal short-term prognosis, with a median survival of 4.7 months. Furthermore, about 40% of patients did not access subsequent treatment.

Brain biopsy is still a minor procedure with not a negligible rate of complications. When performed as a purely confirmatory procedure, a great deal of patients does not access oncological treatments.

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•Unresectable glioblastoma has very poor prognosis.•Few reports about neurooncological outcome in this subgroup of patients.•Brain biopsy is performed in order to access adjuvant treatments.•Brain biopsy is performed also as confirmation of clear MRI findings.•Few reports about benefits and risks of confirmatory brain biopsy.

Unresectable glioblastoma has very poor prognosis.

Few reports about neurooncological outcome in this subgroup of patients.

Brain biopsy is performed in order to access adjuvant treatments.

Brain biopsy is performed also as confirmation of clear MRI findings.

Few reports about benefits and risks of confirmatory brain biopsy.