Intraoperative magnetic resonance imaging and meningioma surgery

ABSTRACT

Objective: To determine if intraoperative magnetic resonance imaging improves surgical resection and postoperative outcome of intracranial meningioma. Study design: Prospective; on-randomized; cohort study Method: Intraoperative Magnetic Resonance Imaging (iMRI) was used to evaluate patients with meningioma undergoing surgery. Images were obtained after induction of anaesthesia and at various stages of tumour resection. Extent of surgical resection was graded using Simpson grading system for meningioma. The images were reviewed together with histopathology and early outcome. Primary outcome measure was determined by finding unexpected tumur in interdissection images. Secondary outcome measures were determined by postoperative complications including infections and mortalities. Results: There were 39 procedures in 38 patients from January 1998 to December 2002. Surgical-planning images helped to optimize craniotomy placement. Interdissection images revealed unexpected residual tumour in only 1 patient. Complete resection (Simpson grades 1-3) was achieved in 33 procedures. The average follow up period was 16.4 months. Tumour recurrence has been observed in three patients. Two of these patients had anaplastic meningioma. There was no mortality in the 30-day postoperative period. Conclusion: Intraoperative MRI was beneficial in siting the craniotomy in addition to providing anatomical relationships between the tumour and adjacent structures in lesions located at the skull base though the full benefit of these is yet to be determined. The low morbidity and zero mortality recorded in the study may be related to all these factors