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BACKGROUND:The current transsylvian or transopercular approaches make access difficult because of the limited exposure of insular tumors. Hence, maximal and safe removal of insular gliomas is challenging. In this article, a new approach to resect insular gliomas is presented. OBJECTIVE: To determine whether the new transfrontal limiting sulcus approach is helpful for maximal and safe removal of insular gliomas. METHODS: The authors reported surgical techniques for insular gliomas resected through the transfrontal limiting sulcus approach. The authors evaluated the surgical resections of 69 insular gliomas performed through the new approach in their department. The extents of resection and postoperative neurological outcomes were analyzed to determine the value of this new approach. RESULTS: Based on the Berger-Sanai classification, most insular gliomas were giant tumors (59.42%), followed by zone I + IV tumors (24.64%). The median (interquartile range) extent of resection of all patients was 100% (91%, 100%). The total resection rate for all gliomas was (55 of 69, 79.7%), and the total resection rate for low-grade gliomas was (28 of 40, 70%), which was significantly lower than that for high-grade gliomas (27 of 29, 93.1%) (P = .019). All patients had muscle strength greater than grade 4 3 months after surgery. Only 1 patient had a speech disorder 3 months after surgery. The median Karnofsky Performance Status score at the time of the 3-month follow-up was 90. CONCLUSION: The transfrontal limiting sulcus approach can help to achieve maximal and safe removal of insular gliomas.

This study developed and evaluated nnU-Net models for three-dimensional semantic segmentation of pituitary adenomas (PAs) from contrast-enhanced T1 (T1ce) images, with aims to train a deep learning-based model cost-effectively and apply it to clinical practice. Methods: This study was conducted in two phases. In phase one, two models were trained with nnUNet using distinct PA datasets. Model 1 was trained with 208 PAs in total, and model 2 was trained with 109 primary nonfunctional pituitary adenomas (NFPA). In phase two, the performances of the two models were investigated according to the Dice similarity coefficient (DSC) in the leave-out test dataset. Results: Both models performed well (DSC > 0.8) for PAs with volumes > 1000 mm3, but unsatisfactorily (DSC < 0.5) for PAs < 1000 mm3. Conclusions: Both nnU-Net models showed good segmentation performance for PAs > 1000 mm3 (75% of the dataset) and limited performance for PAs < 1000 mm3 (25% of the dataset). Model 2 trained with fewer samples was more cost-effective. We propose to combine the use of model-based segmentation for PA > 1000 mm3 and manual segmentation for PA < 1000 mm3 in clinical practice at the current stage.

OBJECTIVE The classic transopercular or transsylvian approach to insular gliomas removes the tumor laterally through the insular cortex. This study describes a new anteroposterior approach through the frontal isthmus for insular glioma surgery. METHODS The authors detailed the surgical techniques for resection of insular gliomas through the transfrontal isthmus approach. Fifty-nine insular gliomas with at least Berger-Sanai zone I involvement were removed with the new approach, and extent of resection and postoperative neurological outcomes were assessed. RESULTS Fifty-nine patients were enrolled in the study, including 35 men and 24 women, with a mean (range) age 44.3 (19–75) years. According to the Berger-Sanai classification system, the most common tumor was a giant glioma (67.8%), followed by involvement of zones I and IV (18.6%). Twenty-two cases were Yaşargil type 3A/B, and 37 cases were Yaşargil type 5A/B. The average angle between the lateral plane of the putamen and sagittal line was 33.53°, and the average width of the isthmus near the anterior insular point was 33.33 mm. The average angle between the lateral plane of the putamen and the sagittal line was positively correlated with the width of the isthmus near the anterior insular point (r = 0.935, p < 0.0001). The median (interquartile range [IQR]) preoperative tumor volume was 67.82 (57.64–92.19) cm3. Of 39 low-grade gliomas, 26 (66.67%) were totally resected; of 20 high-grade gliomas, 19 (95%) were totally resected. The median (IQR) extent of resection of the whole group was 100% (73.7%–100%). Intraoperative diffusion-weighted imaging showed no cases of middle cerebral artery– or lenticulostriate artery–related stroke. Extent of insular tumor resection was positively correlated with the angle of the lateral plane of the putamen and sagittal line (r = −0.329, p = 0.011) and the width of the isthmus near the anterior insular point (r = −0.267, p = 0.041). At 3 months postoperatively, muscle strength grade exceeded 4 in all cases, and all patients exhibited essentially normal speech. The median (IQR) Karnofsky performance score at 3 months after surgery was 90 (80–90). CONCLUSIONS The transfrontal isthmus approach changes the working angle from lateral-medial to anterior-posterior, allowing for maximal safe removal of insular gliomas.