# Voxel-based evaluation of hemorrhage risk in brain biopsies

## TL;DR

This study identifies risk factors for brain biopsy-related hemorrhage and uses voxel-based mapping to show that targeting certain brain regions increases the risk of complications.

## Contribution

The study introduces voxel-based lesion symptom mapping to analyze spatial risk factors for brain biopsy-related hemorrhage.

## Key findings

- High-grade glioma, patient age, and target location are significant predictors of brain biopsy-related hemorrhage.
- Frontal trajectories targeting basal ganglia are associated with higher hemorrhage risk.
- Hemorrhages in the posterior basal ganglia, insula, and capsula interna predict neurological deterioration.

## Abstract

While technological progress increases precision and reduces invasiveness of stereotactic brain biopsies (BB), biopsy related hemorrhage (BBH) is still a key risk. This study identifies risk factors and uses voxel-based lesion symptom mapping (VLSM) to analyse the spatial distribution of BBH. We analyzed 450 frame-based and robotic-assisted BB. Patients’ preoperative MR and postoperative CT imaging were registered and normalized to the standard MNI space enabling volumetry and inter-subject comparison of BBH location. Binary logistic regression analysis was performed to determine significant BBH predictors. Additionally, we performed VLSM to evaluate the exact spatial profile of BBH in relation to the functional outcome. BBH was noted radiographically in 80 cases (18%) with a mean volume of 1.9 ± 19.0 ml. 19/450 (4%) of all BB presented symptomatic BBH characterized mainly by sensorimotor deficits (13/450,3%) and/or reduced vigilance (5/450,1%). 7/450 (2%) cases required surgical evacuation of BBH and 10/450% (2%) patients suffered from persistent neurological deficits. High-grade glioma, patient age and target location were main BBH predictors. VLSM determined frontal trajectories targeting deep-seated lesions in the basal ganglia to be significantly associated with a higher BBH risk. BBH within the posterior aspect of the basal ganglia, insula and capsula interna emerged as significant predictors for neurological deterioration after surgery. While asymptomatic hemorrhages are quite common after brain biopsies, neurological deterioration is rare. BBH risk is influenced by both spatial factors and non-spatial factors. BB targeting basal ganglia were linked to a higher risk of hemorrhage, particularly symptomatic BBH with somatosensory deficit.