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

Introduction 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. Research question This study aims to assess the post-surgical complications and neuro-oncological outcomes of patients undergoing a confirmatory brain biopsy for diagnosing GB. Materials and methods 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. Results 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. Discussion and conclusions 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.