STMO-12 Efforts for safe malignant brain tumor surgery at our hospital

Although maximal safe resection is the current standard for glioblastoma surgery, its safety and removal rate conflict with each other. Electrophysiological monitoring, such as motor evoked potential monitoring and awake craniotomy, can be utilized as safety measures; not all facilities can perform them. Herein, we present a representative case report on our efforts for a safe malignant brain tumor surgery. Case: A 77-year-old woman with glioblastoma in the premotor cortex presented with seizure of the upper left lower limb. Her pyramidal tract ran from the medial bottom to the posterior of the tumor. We performed excision from the site using the lowest gamma entropy. We then removed all parts of the tumor, with the exception of the pyramidal tract infiltration, and no paralysis was observed. She was definitively diagnosed with glioblastoma and is currently on maintenance chemotherapy. As a preoperative examination, we performed cerebrovascular angiography. We then performed various other tests to ascertain the patient’s condition. Considering lesions that affect language, Wada tests were performed regardless of laterality. For all patients with epilepsy onset, preoperative 256-channel electroencephalogram measurement and intraoperative the gamma entropy analysis were performed to confirm epileptogenicity. Considering lesions that affect eloquence, subdural electrodes were placed and brain function mapping was performed the next day. Based on the results, the safest cortical incision site and excision range were determined, and excision was performed on the following day. Of the 14 operated glioblastoma cases after November 2018, more than 85% of the contrast-enhanced lesions were completely removed in 7 cases, partially removed in 5 cases, and underwent biopsy in 2 cases. Postoperative Karnofsky performance status scores remained unchanged in 11 cases, improved in 1 case, and deteriorated in 2 cases. Our efforts have resulted in safe and sufficient removal of malignant brain tumors during surgery.