[New development of surgical treatment for malignant brain tumors]

The most important prognosticator for malignant brain tumor patients is the degree of tumor removal. On the other hand, surgical removal should not induce aggravation of the patient performance status. In accordance with the result, surgical planning for glioma should be carefully considered. However, there is no standard guide for preoperative planning to date. However, there is no standard guide for preoperative planning to the present. We attempted to divide gliomas into 5 stages according to the difficulty of the surgery and analyzed the relation between the removal rate and each stage. The results demonstrated that the stage is correlated with the removal rate. This staging might contribute to standardization of glioma surgery. For surgical planning of tumors around the motor area, fiber tractography and magnetoencephalography should be very useful. As an intraoperative examination, monitoring of motor evoked potential is necessary to resect tumors around the motor area. For resection of tumors around the speech area, functional brain mapping under awake surgery is the most reliable method. In addition to these techniques for safe surgery, neuro-navigation and chemical navigation using 5-aminolevulinic acid are used to achieve of the maximum removal rate. Finally, development of preoperative examinations, microsurgical technique, and intraoperative monitoring enabled us to do safer and move sure surgery.