[Frameless stereotactic biopsy: diagnostic yield and complications]. / Biopsia cerebral estereotáctica sin marco: capacidad diagnóstica y complicaciones.

ABSTRACT

OBJECTIVE: The aim of this study was to evaluate the variables that could modify the diagnostic yield of frameless stereotactic biopsy, as well as its complications. MATERIALS AND METHOD: This was a retrospective study of frameless stereotactic biopsies carried out between July 2008 and December 2011 at Donostia University Hospital. The variables studied were size, distance to the cortex, contrast uptake and location. RESULTS: A total of 70 patients were included (75 biopsies); 39 males and 31 females with an age range between 39 and 83 years. The total diagnostic yield in our series was 97.1%. For lesions >19mm, the technique offered a sensitivity of 95.2% (95% CI 86.9-98.4) and specificity of 57.1% (95% CI 25.0-84.2). The yield was lower for lesions within 17mm of the cortex sensitivity of 74.6% (95% CI 62.1-84.7) and specificity of 71.4% (95% CI 29.0-96.3). Seven (10%) patients developed complications after the first biopsy and none after the second. CONCLUSIONS: The diagnostic yield was lower for lesions less than 2cm in size and located superficially. In this series we did not observe an increased rate of complications after a second biopsy.