Introduction: Image-guided stereotactic brain biopsy is an established method to obtain histopathological diagnosis and guide management for cerebral lesions. Evaluation of biopsy methods and associated risks is essential. This study aimed firstly to establish negative biopsy and symptomatic haemorrhage rates at a single center, and secondly to assess the influence of factors such as lesion location, final pathology and the use of intra-operative smears.
Methods: A retrospective analysis of case notes, theatre records and radiological imaging of all frame-based and frameless biopsies carried out over 57 months from July 2006 to March 2011.
Results: A total of 351 biopsies were undertaken in the time frame, 256 frame-based (73%) and 95 frameless (27%). 57% of subjects were male. Mean age was 57 years (range 18-87). Negative biopsy rate was 5.2%. There was a significantly greater negative biopsy rate in deep brain biopsies (p=0.011) and in the cerebellum (p<0.001). Intra-operative smear significantly reduced negative biopsy rates from 8.3% to 4.4% (p=0.011). If repeat smear was requested yet not provided then the negative biopsy rate was 57.1% (p=0.0045). The overall symptomatic haemorrhage rate was 3.7%. There was no significant increase in haemorrhage rate in brain stem and thalamic or in high grade biopsies. There was a significantly greater haemorrhage rate in lymphoma biopsies (p=0.015). Mortality rates at 7 and 30 days post-operatively were 0.6% and 1.7% respectively, with mortality after 7 days unrelated to biopsy.
Conclusions: The results compare favorably with published morbidity and mortality rates that reinforce the acceptably low complication and negative biopsy rates associated with image guided brain biopsy. We advocate intra-operative histopathological analysis to decrease negative biopsy rates and advise increased caution when undertaking biopsies of suspected lymphoma due to the potentially increased risk of haemorrhage.
Patient Care: Having an accurate assessment of the morbidity and mortality associated with stereotactic brain biopsies and the factors affecting them allows clinicians the ability to change their practice to minimise the risk to patients. This is especially the case for the routine use of intra-operative histological analysis to minimise the risk of a negative biopsy and therefore the need for repeat biopsy. A clear understanding of the risk associated with biopsy also enables the clinician to carry out better informed consent when explaining the risks and benefits. This, in turn, allows patients to be in a better position to make an informed decision about undergoing the procedure.
Learning Objectives: By the conclusion of this session participants should be able to
1) Have an understanding of the yield and complications of frame-based and frameless stereotactic brain biopsy from the results of a large single-centre retrospective study,
2) Evaluate the importance of intra-operative histological analysis in minimising negative biopsy rates,
3) Identify the risk factors for increased negative biopsy and symptomatic haemorrhage rates and reflect on the significance of these factors when planning to undertake a biopsy on a patient.