Impact of a low-field intraoperative MRI on the surgical results for high-grade gliomas.

In this study the authors retrospectively evaluated the results of the operated intracranial high grade gliomas using low field intraoperative MRI system Polestar N 20+Stealth Station (Medtronic, Co, USA) at German Hospital, Istanbul. Between November 2006 and October 2008, 11 patients underwent microsurgical tumor resection with the use of intraoperative MRI for WHO Grade III and IV gliomas. There were six males and five females, mean age was 53 (range 30-73), and mean follow-up duration was 19 months (range 4-31). Ten total, one subtotal resection was achieved, whereas intraoperative MRI assessment demonstrated five residual tumors. Histopathological examination revealed that eight tumors were glioblastomas and three were anaplastic oligodendroglioma, anaplastic oligoastrocytoma and anaplastic ependymoma respectively. No complications directly related to the intraoperative scanning were observed and there was no mortality, but one patient with an insular tumor developed hemiparesis after the operation. Mean hospital stay was 4.8 day. Ten patients received additional radiotherapy and chemotherapy, one patient refused further therapy. Mean survival was 18.8 months for the entire group and 15.6 months for glioblastoma patients. In this small series of patients with high grade gliomas we found that the use of intraoperative MRI helps complete tumor removal and hence improves survival.