Fig. 1
Surgical plan, approach design and process of GA. The patient was a 48-year-old woman with no preoperative symptoms and a KPS of 100. A Preoperative multimodal MRI showed a lesion in the left frontotemporal and insula lobes. Upper and lower left: Hyperintensity on T2 and FLAIR. Upper right: No obvious enhancement was found on T1C. Lower right: DTI showed that the lesion was close to the pyramidal tract, language cortices and tracts. B, C Surgical plan of neuronavigation showing the tumor (green), Broca area (red), Wernicke area (blue), PT (pink), AT (yellow) and inferior occipito-frontal tract (light green). Measurements: tumor volume, 36.03 cm3; shortest distance to PT, 3.8 mm; shortest distance to AT, 0 mm. D Registration by scanning the patient’s head and face with a laser indicator Z-touch®. E The surgeon designed the surgical approach and incision according to the guidance of the navigation probe and screen. F Needle electrodes were placed into the patient’s scalp and limbs for IONM. G Craniotomy through the pterion approach exposed the frontotemporal cortex and sylvian fissure. H Removed tumor under a microscope and guided by neuronavigation. Upper left: the avoided Broca area and part of the operculum were removed to expose the tumor of the insular lobe. Upper right: tumor sample was taken for pathology examination. Lower left: Removed tumor in the deep part insular to the surface of the putamen; the MCA and its branches were protected. Lower right: removed tumor of the deep part of the temporal lobe. I IONM system, MEP induced by transcranial stimulation compared with MEP at baseline. Changes in MEP, SEP, and current intensity by DES can locate the PT. J Intracranial MEP (upper left), MEP induced by DES (upper right), SEP (lower left), and EEG (lower right). IONM showed that the amplitude of the terminal MEP in the right limbs decreased and EEG showed no epileptic discharge. K A neuronavigation probe was used to detect the edge of the resection cavity and tracts in real time. L iMRI scanning. M iMRI showed a residual tumor located at the back of the cavity, close to the back of the putamen and the posterior limb of the internal capsule. The surgical plan was updated. N Removed residual tumor. O Pre, intra, and postoperative MRI. The final EOR was 100%. Pathology: anaplastic oligodendroglioma, WHO 3. At one week postoperatively, the muscle strength of the right upper and lower limbs was grade 4 and 3, respectively. At 3 and 6 months postoperatively, the muscle strength of the right limbs was grade 4 and 4.5, respectively. Radiotherapy plus concomitant and adjuvant TMZ chemotherapy were performed. No tumor recurrence or death occurred until the follow-up date, and PFS and OS were both 28.7 months