Comparing the risks of frameless stereotactic biopsy in eloquent and noneloquent regions of the brain: a retrospective review of 284 cases Clinical article

Object. Frameless stereotactic biopsy has been shown in multiple studies to be a safe and effective tool for the diagnosis of brain lesions. However, no study has directly evaluated its safety in lesions located in eloquent regions in comparison with noneloquent locations. In this study, the authors determine whether an increased risk of neurological decline is associated with biopsy of lesions in eloquent regions of the brain. Methods. Medical records, including imaging studies, were reviewed for 284 cases in which frameless stereotactic biopsy procedures were performed by 19 neurosurgeons at 7 institutions between January 2000 and December 2006. Lesion location was classified as eloquent or noneloquent in each patient. The incidence of neurological decline was calculated for each group. Results. During the study period, 160 of the 284 biopsies predominately involved eloquent regions of the brain. In evaluation of the complication rate with respect to biopsy site, neurological decline occurred in 9 (5.6%) of 160 biopsies in eloquent brain areas and 10 (8.1%) of 124 biopsies in noneloquent regions; this difference was not statistically significant (p = 0.416). A higher number of needle passes was associated with the presence of a postoperative hemorrhage at the biopsy site, although not with a change in the result of neurological examination. Conclusions. Frameless stereotactic biopsy of lesions located in eloquent brain regions is as safe and effective as biopsy of lesions in noneloquent regions. Therefore, with careful planning, frameless stereotactic biopsy remains a valuable and safe tool for diagnosis of brain lesions, independent of lesion location. (DOI: 10.3171/2009.3.JNS081695)