Multiparametric MRI to stratify risk factors for hemorrhagic complications in inoperable glioblastomas following stereotactic needle biopsy

Purpose: Histological confirmation of glioblastoma (GB) is essential for therapeutic planning, even in inoperable cases where stereotactic needle biopsy (STNB) is the only option. However, post-procedural bleeding remains a known risk. This study aimed to evaluate the association between MRI features of GB and hemorrhagic complications following STNB. Methods: This retrospective, single-center study included 78 patients with IDH-wildtype GB (mean age: 61 years; 33 females) who underwent pre-biopsy MRI (including SWI and DSC-perfusion) and post-biopsy CT within 72 h. Lesions were anatomically classified into four groups based on their location: cortical/superficial grey matter (sGM n = 12), subependymal white matter (sWM; n = 36), deep nuclei/thalamus (n = 26), or brainstem (n = 4). Hemorrhage incidence and area were correlated with lesion location, intratumoral susceptibility signal (ITSS) grade, rCBVmax values, and peritumoral edema. Clinical outcomes were also recorded. Results: Hemorrhage incidence significantly differed by lesion location (p = 0.009), with the highest frequency in deep lesions (85%). Most non-hemorrhagic cases (53%) occurred in sWM. While rCBVmax did not correlate with hemorrhage incidence, a significant linear association with hemorrhage area was noted (p = 0.016, r = 0.331). Grade 3 ITSS lesions showed more extensive bleeding. No correlation was found between peritumoral edema and bleeding. Most hemorrhages were asymptomatic; only two patients experienced transient neurological symptoms. Conclusions: Lesion location was the strongest predictor of post-biopsy hemorrhage. The absence of correlation between rCBVmax and bleeding risk suggests biopsies can be safely performed even in hyperperfused (and potentially more aggressive) tumor areas. STNB remains a safe and valuable diagnostic tool when appropriate preoperative evaluation and postoperative monitoring are ensured.