Pushing the boundaries of neurosurgical oncology: evaluating the superiority of supratotal resection over gross total resection in intraoperative MRI-guided glioma surgery

Using intraoperative MRI (iMRI) in glioma surgery can enhance the extent of resection (EOR) and improve survival rates for patients diagnosed with low grade gliomas (LGG) or high grade gliomas (HGG). This study focused on patients who underwent iMRI-guided surgery for LGG and HGG at our center. Our objective was to compare the patient survival time and recurrence rate between supratotal resection (SpTR) and gross total resection(GTR). To the best of our knowledge, this is the first study comparing SpTR with GTR using iMRI in glioma surgery. This study included 71 patients who had undergone iMRI-guided GTR and SpTR. The volume of the tumors was measured using postcontrast 3D T1W series and 3D FLAIR series taken the day before surgery, and the volume of the operation cavity was calculated from iMRI images. The effects of SpTR and GTR on overall and progression-free survival (OS and PFS) were analyzed by the log-rank test using Kaplan‒Meier curves. The associations between the extent of resection and tumor grade, and between recurrence and tumor grade were examined using the chi-square test. The rate of recurrence in patients diagnosed with HGG was greater than that in patients diagnosed with LGG (p = 0.022). While patients who received SpTR had a greater OS time (105.9 months) than did those who underwent GTR (92.8 months), the difference was not statistically significant. The patients with LGG had a significantly longer PFS time than did the patients with HGG (86.5 ± 5.9 months, 95% CI = 74.9-98.2, p < 0.0001). Of 23 patients diagnosed with HGG, SpTR was achieved in 9 and GTR was achieved in 14. The median OS time was longer in patients who underwent SpTR than in those who underwent GTR, but there was no statistically significant difference [101.2 ± 20.5 months (95% CI: 80.7-121.7) vs. 70.6 ± 9.9 (95% CI: 60.7-80.5) p = 0.9]. Neurosurgeons are increasingly choosing SpTR, especially in LGGs. Despite their slow growth, LGGs retain the potential for malignant transformation. This situation underscores the importance of maximum safe resection in the surgery of LGGs. iMRI-guided resection makes it easier for surgeons to show the EOR concurrent with the operation.