Wax pile method for glioma surgery utilizing intraoperative magnetic resonance imaging: a technical note

Over the past decade, intraoperative magnetic resonance imaging (iMRI) to facilitate precise resection of brain tumors has been introduced to the field of brain tumor surgery. We have started using a technique for brain tumor resection involving precise placement of silicone tubes filled with bone wax under iMRI, which we call the “wax pile” method. From July 2008 to August 2012, a total of 31 patients with glioma were surgically treated by craniotomy utilizing iMRI. The wax pile method was used to treat 16 patients with glioma, including 9 cases of glioblastoma, 2 cases of anaplastic astrocytoma, 4 cases of oligodendroglioma, and 1 case of low-grade astrocytoma. To determine the resection margins, 4-6 tubes were inserted around the tumor and tube positions were confirmed on iMRI. Extent of tumor removal was total in 10 cases (62.5%) and partial (<95% removal) in 6 cases (37.5%). “Wax piles” with clear contours and sharp neuroimages were quite useful as intraoperative markers for determining the depth and range of the lesions under iMRI. Tumors were removed safely and accurately. Karnofsky performance status (KPS) score ranged from 40 to 100 preoperatively, and was not deteriorated postoperatively in any case. No complications due to tube insertion were encountered. The present study demonstrated that the wax pile method offers a safe, accurate technique for glioma surgery without concern for brain shift during tumor resection under iMRI.