gms | German Medical Science

Objective: Describe the method, the procedure and results of the combination of intraoperative MRI and awake craniotomy.

Methods: From 09/2005 to 09/2009 322 gliomas were operated within an integrated iMRI-OR. For 60 patients with tumors adjacent to or within eloquent areas awake craniotomy with direct cortical stimulation (DCS) and neuropsychological monitoring was indicated. We evaluated patient perception of the procedure prospectively. Growth pattern and potential resectability was assessed based on preoperative structural and functional MRI as well as neuropsychological evaluation. Resection rate was calculated comparing pre-, intra- and postoperative images. Neurological follow-up was gathered every 3 month, neuropsychological FU immediately post-operatively and on request during the outpatient controls.

Results: After thorough clinical and neuropsychological evaluation 60 patients were deemed eligible for awake craniotomy and were operated in the integrated iMRI suite. Gender distribution was 34 male with 35, and 23 female with 25 awake surgeries. Mean age was 45±14 (15–78). Histopathology was 18 grade IV, 15 III, 7 grade I–II and 20 recurrent gliomas. 48 lesions were on the left, 12 on the right (11 motor, 1 speech) side. Overall 35 patients underwent motor and 25 speech monitoring. Surgery was performed with Neuronavigation until intraoperative updates were deemed necessary. Imaging sessions consisted of T2-WI and enhanced and non-enhanced T1-WI depending on the presurgical MRI-appearance of the lesion. Five patients did not obtain intraoperative scans. In 40 patients one intraoperative imaging session was performed, in 10 patients two and in five patients three or more. These data sets were used for updated navigation. Of the prospectively evaluated patients (n=24) 21 patients stated that they would undergo the same procedure again, while three were undecided. Despite the location prompting awake craniotomy gross total resection could be achieved in up to 60%. Around 10% had permanent neurological deficits.

Conclusions: Awake craniotomy and iMRI is a technically feasible approach to tumors in or adjacent to eloquent areas. Patient perception is hardly influenced by the elaborate procedure which considerably challenges patient cooperation. Intraoperative structural MRI as well as online motor and speech testing form an ample basis for surgical decision making.