Towards improving the safety and diagnostic yield of stereotactic biopsy in a single centre.

Background: Previously, we reported on our single centre results regarding the diagnostic yield of stereotactic needle biopsies of brain lesions. The yield then (1996-2006) was 89.4%. In the present study, we review and evaluate our experience with intraoperative frozen-section histopathologic diagnosis on-demand in order to improve the diagnostic yield.

Methods: One hundred sixty-four consecutive frameless biopsy procedures in 160 patients (group 1, 2006-2010) were compared with the historic control group (group 2, n = 164 frameless biopsy procedures). Diagnostic yield, as well as demographics, morbidity and mortality, was compared. Statistical analysis was performed by Student's t, Mann-Whitney U, Chi-square test and backward logistic regression when appropriate.

Results: Demographics were comparable. In group 1, a non-diagnostic tissue specimen was obtained in 1.8%, compared to 11.0% in group 2 (p = 0.001). Also, both the operating time and the number of biopsies needed were decreased significantly. Procedure-related mortality decreased from 3.7% to 0.6% (p = 0.121). Multivariate analysis only proved operating time (odds ratio (OR), 1.012; 95% confidence interval (CI), 1.000-1.025; p = 0.043), a right-sided lesion (OR, 3.183; 95% CI, 1.217-8.322; p = 0.018) and on-demand intraoperative histology (OR, 0.175; 95% CI, 0.050-0.618; p = 0.007) important factors predicting non-diagnostic biopsies.

Conclusions: The importance of a reliable pathological diagnosis as obtained by biopsy must not be underestimated. We believe that when performing stereotactic biopsy for intracranial lesions, next to minimising morbidity, one should strive for as high a positive yield as possible. In the present single centre retrospective series, we have shown that using a standardised procedure and careful on-demand intraoperative frozen-section analysis can improve the diagnostic yield of stereotactic brain biopsy procedures as compared to a historical series.