gms | German Medical Science

Objective: Intraoperative magnetic resonance imaging (iMRI) is a method to substantiate quality control in glioma surgery by evaluation of the extent of resection and because of the possibility of achieving complete tumor resection. The aim of this study was to investigate the results of 131 patients with low grade glioma, who underwent surgery with intraoperative magnetic resonance imaging.

Methods: All patients suffered from gliomas WHO grade I and II and were operated in a iMRI-suite equipped with a 1.5 T standard MR scanner and active shielding. Neuronavigation and presurgical functional brain imaging were used in the majority of the patients. In all patients intraoperative MR imaging was employed to determinel the extent of resection and if appropriate update the navigation for further tumor removal. Complete resection was defined as total resection of the hypointense signal changes of the tumor in T1 weighted imaging.

Results: Out of 131 patients with low grade glioma, 95 underwent craniotomy for tumor resection and 37 patients were treated with stereotactic biopsy. In 66 patients complete resection was achieved (69%). Of these, 9 patients were operated with an update of navigation after initial incomplete resection (14%). Incomplete resection resulted in 29 patients (31%), of these in 11 patients an intended incomplete resection was planned beforehand. However, further tumor resection was performed in 9 cases which led to a mean tumor removal of 87% of the initial mass. Postoperative neurological deficits were encountered in 8% of the operated patients.

Conclusions: Surgery of low grade gliomas with iMRI can significantly increase the completeness of resection or additional tumor debulking. In respect to oncological criteria, the patients may benefit from the increased cytoreduction with a low postoperative morbidity.