The role of early intra-operative MRI in partial resection of optic pathway/ XXXX in @entity1 .

@entity11 @entity1 @entity5
INTRODUCTION: Optic pathway/ @entity11 (OPHGs) are generally benign but situated in an exquisitely sensitive brain region. They follow an unpredictable course and are usually impossible to resect completely. We present a case series of 10 @entity1 who underwent surgery for OPHGs with the aid of intra-operative MRI (ioMRI). The impact of ioMRI on OPHG resection is presented, and a role for ioMRI in partial resection is discussed. METHODS: Ten @entity1 with OPHGs managed surgically utilising ioMRI at Alder Hey @entity1 's Hospital between 2010 and 2013 were retrospectively identified. Demographic and relevant clinical data were obtained. MRI was used to estimate @entity5 volume pre-operatively and post-resection. If ioMRI demonstrated that further resection was possible, second-look surgery, at the discretion of the operating surgeon, was performed, followed by post-operative imaging to establish the final status of resection. @entity5 volume was estimated for each MR image using the MRIcron software package. RESULTS: Control of @entity5 progression was achieved in all @entity1 . Seven @entity1 had, on table, second-look surgery with significant further @entity5 resection following ioMRI without any surgically related mortality or morbidity. The median additional quantity of @entity5 removed following second-look surgery, as a percentage of the initial total volume, was 27.79  % (range 11.2-59.2  %). The final @entity5 volume remaining with second-look surgery was 23.96 vs. 33.21  % without (p  =  0.1). CONCLUSIONS: OPHGs are technically difficult to resect due to their eloquent location, making them suitable for debulking resection only. IoMRI allows surgical goals to be reassessed intra-operatively following primary resection. Second-look surgery can be performed if possible and necessary and allows significant quantities of extra @entity5 to be resected safely. Although the clinical significance of additional @entity5 resection is not yet clear, we suggest that ioMRI is a safe and useful additional tool, to be combined with advanced neuronavigation techniques for partial @entity5 resection.
