Please cite this article in press as: Yordanova YN, Duffau H. Supratotal resection of diffuse gliomas – an overview of its multifaceted implications. Neurochirurgie (2017), http://dx.doi.org/10.1016/j.neuchi.2016.09.006 ARTICLE IN PRESS G Model NEUCHI-825; No. of Pages 7 Neurochirurgie xxx (2017) xxx–xxx Disponible en ligne sur ScienceDirect www.sciencedirect.com Update Supratotal resection of diffuse gliomas – an overview of its multifaceted implications Y.N. Yordanova a,c,* , H. Duffau b,c,d a Department of neurosurgery, “Percy” Military Hospital, 101, avenue Henri-Barbusse, 92140 Clamart, France b Department of neurosurgery, hôpital Gui-de-Chauliac, Montpellier University Medical Center, 80, avenue Augustin-Fliche, 34295 Montpellier, France c National Institute for Health and Medical Research (Inserm), U1051, Team “Plasticity of the central nervous system, human stem cells and glial tumors“, Institute for Neurosciences of Montpellier, Montpellier University Medical Center, 80, avenue Augustin-Fliche, 34091 Montpellier, France d University of Montpellier, 163, rue Auguste-Broussonet, 34090 Montpellier, France a r t i c l e i n f o Article history: Received 26 April 2016 Received in revised form 20 September 2016 Accepted 27 September 2016 Available online xxx Keywords: Diffuse glioma Overall survival Quality of life Supratotal resection a b s t r a c t Successful management of diffuse low-grade and high-grade gliomas in adults is a challenge for neuro- oncologists. Indeed, due to their highly infiltrative feature, these diseases remain incurable despite therapeutic advances. Nevertheless, the elaboration of individualized therapeutic strategies has led to an improvement of both overall survival and quality of life. In particular, the impact of surgical resection on diffuse glioma survival has been extensively demonstrated. However, this impact is significant only when the resection is total (i.e., complete removal of the T2-hyperintensity in diffuse low-grade gliomas, or complete removal of the enhancement in high-grade gliomas), or at least subtotal. Interestingly, biopsy samples within and beyond the abnormalities, defined by magnetic resonance imaging, have shown that the actual spatial extent of gliomas was underestimated by this conventional imaging modality, since glioma cells were present outside the signal abnormalities. Thus, it was suggested that the removal of a margin around the tumor visible on magnetic resonance imaging, i.e. “supratotal resection”, might improve the outcomes in diffuse gliomas. To achieve this type of supramaximal resection, while preser- ving the quality of life, a new concept is to switch from an image-guided surgery to a functional-guided surgery, i.e. to pursue the resection up to the eloquent neural networks using intraoperative direct elec- trical stimulation mapping in awake patients. The aim of this article was to review the recent data about supratotal resection, including both oncological and functional results. Favorable outcomes have recently opened the door to the principle of “preventive surgery” in incidentally discovered gliomas, and to the proposal of a medical screening. © 2016 Elsevier Masson SAS. All rights reserved. 1. Diffuse gliomas – current understanding Diffuse gliomas – the most common primary central nervous system tumors, are a heterogeneous group of neoplasms composed of both high-grade gliomas (HGG), according to the World Health Organization (WHO) classification grade III and IV, and diffuse low- grade gliomas (DLGG), WHO classification grade II. In spite of their widely variable behavior and survival rate, diffuse gliomas share many common features. Probably the most important of them is their ability to diffusely invade the surrounding brain tissue. It is now acknowledged that isolated glioma cells, permeating the brain around the bulk of the tumor mass, are responsible for the con- * Corresponding author. Department of neurosurgery, “Percy” Military Hospital, 101, avenue Henri-Barbusse, 92140 Clamart, France. E-mail address: yn.yordanova@gmail.com (Y.N. Yordanova). stant glioma recurrence, even after “complete” surgical resection. In reality, current imaging modalities, including high-field magnetic resonance imaging (MRI), are unable to detect gliomas before they reach a given cell density threshold [1]. This unavoidable underes- timation of the actual spatial extension of diffuse gliomas is critical for their poor assessment and unsatisfactory treatment. HGG are highly proliferative and infiltrative tumors whose sur- vival rates have barely changed over the past decades, despite advances in oncological treatment. Their prognosis remains poor even after a standardized multimodal therapeutic approach, including surgery and adjuvant chemoradiation. Tumor recurrence is unavoidable, and the median overall survival (OS) of the highest histological grade – the glioblastoma (GBM), still ranges from 9 to 22 months [2]. Indeed, multiple stereotactic biopsies have clearly demonstrated the presence of glioma cells far beyond the imaging abnormalities [3]. Thus, after treatment, the rapid growth of resid- ual cancer stem cells and their incessant genetic modifications are http://dx.doi.org/10.1016/j.neuchi.2016.09.006 0028-3770/© 2016 Elsevier Masson SAS. All rights reserved.