Study Of The Reliability Of The Application Of High-field Intraoperative Magnetic Resonance Imaging In Glioma Resections And Its Impact On The Extension Of Resection

Objective:To evaluate the reliability of high-field intraoperative magnetic resonance imaging(iMRI) in detecting residual tumors during glioma resections and the impact of high-field iMRI on extension of resection and surgical strategy modification for glioma surgery. Methods:Applying of iMRI in 131 patients after satisfactory tumor resection by conventional navigative microscope. Residual tumors which were difficult to detect under the microscope were detected by iMRI and resected for pathological examination. In 106 glioma of whom, questionnaire form were filled and collected prospectively to record the surgeons'intention(total, subtotal, or partial) of the extent of resection (EoR) and the intra-operative estimation of EoR before every iMRI scan. After each scan, the percentage of tumor removal was calculated according to the imaging data. The impact of iMRI on the tumor EoR and modification of surgical strategy was then evaluated. Results:High quality intraoperative images were obtained by using of high-field iMRI. Twenty-eight patients was excluded because their residual tumors were not resected for close to functional area. As determined by pathological results and postoperative MRI at the early recovery stage, the sensitivity rate of iMRI in residual tumor detection was 98.0% (49/50), specificity rate was 94.3% (50/53), and accuracy rate was 96.1% (99/103).In 106 glioma of whom, pre-operatively,48 cases were planned to totally resected. The first intraoperative MRI scan revealed 42(39.6%) cases were completely resected, while in 64(60.4%) cases, residual tumors were detected. Further tumor resections were performed in 39 cases. Of which,25 cases obtained complete resection. Finally, in the whole cohort,67 cases got complete removal, significantly increasing the total removal rate from 45.3% (48/106 cases) to 63.2% (67/106 cases). Even for those cases with which total resection couldn't be achieved, residual tumor volume was significantly decreased. The percentage of average volume of tumor resected also rises obviously from (86.3±20.2)% at the first scan to (93.6±12.4)% at the final scan. The difference is of statistical significance (U=4, P=0.0003). Conclusion:High-field iMRI can povide high-quality intraoperative imaging and therefore is a safe and reliable method in detecting residual tumors during glioma resections. It can also increase the extent of glioma resection, and has significant impact on the intra-operative modification of the surgical strategy.