SURG-18IMPACT OF INTRAOPERATIVE MRI ON SURGICAL OUTCOME IN PATIENTS WITH GLIOMAS

Abstract

INTRODUCTION: The management of gliomas is based on a first-line surgical resection when significant tumor reduction can be achieved. Since our institution is equipped with a 1.5T Intraoperative MRI (IoMRI), we evaluated its impact on the extent of resection of gliomas, clinical outcomes and survival. METHODS: All patients operated on for gliomas using the IoMRI since its installation were systematically included. Functional MRI determined the cerebral dominance. Intraoperative evaluation of resection used a 3D FLAIR /T2 or T13D with gadolinium based on preoperative tumor aspect, enhancing or not, automatically updating the neuronavigation. We studied clinical data, the course of the surgical procedure (number of MRI control, sequences used, operative time). Postoperative residual tumor volume after early postoperative MRI control (<72 h) was compared with the preoperative volume. RESULTS: 55 glial tumors were operated on using IoMRI. 60% of gliomas were "de novo", 40% were recurrences. Histological analyses reported a majority of grade II and III. Their main location was the frontal lobe (38%), with a consistent group of fronto-temporo-insular tumors. Most patients only had one peroperative MRI control, lasting 39 min in average. If needed the second IoMRI was shorter, 23 min. The average preoperative tumor volume was 32.66 cm2, and postoperative volume of 1.11 cm2. Complete resection was reached in 70%. Low-grade gliomas required more IoMRI controls than high grade. The use of IoMRI has not been associated with an increased rate of complications (infectious, hemorrhagic). We noticed a temporary increase of neurological deficits during the post-operative week, not found 3 months later. CONCLUSION: IoMRI optimized the removal rate without additional complication despite an extension of the operating time of 1:30 on average. During dissection of critical areas, such as fronto-insular region, IoMRI allowed to readjust neuronavigation, offsetting brain shift and ensuring greater accuracy for surgical resection