P28 * BRAINSTEM BIOPSY: A SAFE AND ACCURATE DIAGNOSTIC TOOL

Abstract

INTRODUCTION: Brainstem tumours account for 10-25% of tumours in children and 2% in adults. Accurate diagnosis is crucial for treatment planning and prognosis and despite advances in the development of medical imaging, tissue diagnosis remains the diagnostic gold standard. METHOD: Retrospective study of patients who underwent stereotactic brainstem biopsy between 2001 and 2010. Radiological and tissue diagnosis, surgical morbidity and mortality, and survival time for low and high grade gliomas after biopsy and treatment were recorded. RESULTS: 42 patients were analysed, 28 adults, 14 paediatrics. Main presenting symptoms were diplopia (52.4%) and gait disturbance (38.1%). Procedure-related mortality was 0%, and minor morbidity was 11.9%. Histological diagnosis was obtained in 95.2% of cases as follows: low grade glioma (45.2%), high grade glioma (31.0%), primary CNS lymphoma (7.1%), brainstem infarction (7.1%), metastasis (4.8%) and inconclusive (4.8%). Pre-operative radiological diagnosis was unclear in 25 cases (59.5%), and failed to identify 12 out of 13 (92.3%) high grade gliomas, and 10 out of 19 (52.4%) low grade gliomas. The 2 metastasis in our study were diagnosed pre-operatively whilst lymphomas and infarcts were unclear. The median overall survival for low grade gliomas was 13 and 7 months in adults and children respectively, whilst for high grade gliomas 12 and 6 months for adults and children respectively. CONCLUSION: Brainstem biopsy remains an important diagnostic tool despite the advances in neuro-imaging. It is an accurate and safe procedure that provides tissue diagnosis to guide tumour management as well as tumour biobanking for future research.