Brainstem tumors are heterogenous and cancerous glioma tumors arising from the midbrain, pons, and the medulla that are relatively common in children, accounting for 10% to 20% of all pediatric brain tumors. However, the prognosis of aggressive brainstem gliomas remains extremely poor despite aggressive treatment with chemotherapy and radiotherapy. That means there are many life-threatening patients who have exhausted all available treatment options and are beginning to face end-of-life stage. Therefore, the unique properties of highly selective heavy particle irradiation with boron neutron capture therapy (BNCT) may be well suited to prolong the lives of patients with end-stage brainstem gliomas. Herein, we report a case series of life-threatening patients with end-stage brainstem glioma who eligible for Emergency and Compassionate Use, in whom we performed a scheduled two fractions of salvage BNCT strategy with low treatment dosage each time. No patients experienced acute or late adverse events related to BNCT. There were 3 patients who relapsed after two fractionated BNCT treatment, characterized by younger age, lower T/N ratio, and receiving lower treatment dose. Therefore, two fractionated low-dose BNCT may be a promising treatment for end-stage brainstem tumors. For younger patients with low T/N ratios, more fractionated low-dose BNCT should be considered.

Background: The white matter dissection technique owes its modern recognition to Josef Klingler, whose fixation protocol enabled detailed fiber bundle visualization and led to an outstanding and still relevant atlas of white matter anatomy. After a period of decline in the late twentieth century, the technique was reintroduced into neurosurgical training with the aid of the surgical microscope, emphasizing the importance of fiber dissection and its practical applications in clinical neuroanatomy. This article provides a structured, step-by-step demonstration of white matter microdissection, progressing from superficial anatomy to deeper fiber layers. Its main contribution is the supplementary video, which offers a detailed, structured demonstration of the dissection steps and white matter layers, replicating the format and clarity of hands-on dissection courses. Careful editing and post-processing were applied to optimize educational impact. Methods: The dissection was recorded during the 7th Sulci, Gyri, Ventricles and Fiber Dissection Hands-on Course (Taipei, November 2024). Identifiable participants gave informed consent for publication. Results: The video illustrates a systematic lateral-to-medial dissection, beginning with sulcal and gyral identification. Grey matter is removed to expose U-fibers, followed by progressive visualization of the superior longitudinal fasciculus, insular cortex, extreme and external capsules, claustrum, basal ganglia, and anterior commissure. Each step is accompanied by commentary and technical tips to guide the dissection and preserve anatomical integrity. Conclusion: By mastering the topography of white matter, neurosurgeons can enhance their understanding of pathological anatomy, allowing for precise mental rehearsal and strategic planning before surgery. This approach underscores the enduring importance of anatomical studies in improving surgical outcomes and advancing neurosurgical practice.

Purpose This study was to determine whether combining blood-brain-barrier-penetrant tyrosine kinase inhibitor (TKI), osimertinib, with intracranial radiotherapy (TKI + RT) would confer benefits exceeding those of osimertinib alone (TKI-alone) in terms of treatment outcomes among non-small cell lung cancer (NSCLC) patients with brain metastases and epidermal growth factor receptor (EGFR) mutation. Methods This single-center retrospective study focused on gamma-knife radiosurgery (GKRS) and whole brain radiotherapy (WBRT). Treatment outcomes included intracranial local tumor control, intracranial distant tumor control and overall survival (OS) rates. Results This study included 567 brain metastases in 69 patients: TKI-alone (n = 38) and TKI + RT (n = 31) including GKRS (n = 25) and WBRT (n = 6). Intracranial local tumor control at 36 months was significantly higher in the TKI + RT than in the TKI-alone (77% vs. 23%; p < 0.001). Intracranial distant tumor control was significantly higher in the TKI + RT than in the TKI-alone (median survival: 23.2 ± 1.5 vs. 8.7 ± 0.2 months; p < 0.001). We observed no difference between the two cohorts in terms of OS (p = 0.271). T790M point mutation (HR = 0.359, p = 0.008) and TKI + RT (HR = 0.396, p = 0.010) were positively correlated with intracranial local tumor control. The number of brain metastases was negatively correlated with intracranial distant tumor control (HR = 2.253, p = 0.034) and OS (HR = 2.049, p = 0.019). Conclusions The efficacy of osimertinib therapy for NSCLC patients with brain metastases and EGFR mutation was enhanced by combining this treatment with intracranial radiotherapy. Benefits were observed in terms of intracranial local control and distant control rates; however, no benefits were observed in terms of OS. Further prospective studies will be required to confirm these findings.

Rosette-forming glioneuronal tumors (RGNT) are rare and novel World Health Organization grade I neoplasms that typically arise in the fourth ventricle and progress slowly. Surgical resection is the standard treatment. However, owing to their adherence to critical structures, complete resection is often not possible. The role of stereotactic radiosurgery (SRS) in the management of RGNT remains inconclusive. We present a case of tissue-confirmed RGNT successfully treated with SRS. A 24-year-old woman presented with diplopia and dysequilibrium and was subsequently diagnosed with a fourth ventricular tumor. Subtotal resection was performed at another hospital, and a tissue-based diagnosis of RGNT was made. After a multidisciplinary discussion and following the patient’s willingness, single-session SRS was prescribed at a marginal dose of 12 Gy. During the subsequent 66-month follow-up period, radiologic regression of the tumor with corresponding resolution of symptoms was noted. She remained neurologically intact at her last official visit. The treatment paradigm for residual RGNT remains elusive due to its scarcity and varied presentation. We have presented our preliminary experience with a residual RGNT that was managed with SRS, attaining long-term freedom from tumor progression. SRS may be a safe, effective, and durable treatment modality for patients with RGNT.

Background: White matter microdissection represents a valuable method for studying the three-dimensional organization of the human brain. Building on Klingler’s classical technique, this approach has regained importance as both a research and educational tool in microneurosurgery. While the white matter dissection of the lateral aspect of the brain has been extensively described, the medial surface has received comparatively less attention. This article represents the second part of a three-paper series on white matter microdissection. It provides a structured, step-by-step demonstration of the dissection of the medial aspect of the brain, with a specific focus on the limbic lobe. As in the first paper, the core content is the supplementary video, which, through editing and annotation, has an enhanced didactic value. Methods: The dissection was performed according to the Klingler technique and recorded during the 8th Sulci, Gyri, Ventricles and Fiber Dissection Hands-on Course (Taipei, 2025). The procedure was conducted under microscopic magnification and edited into a didactic video presentation. All identifiable participants provided informed consent for publication. Results: The dissection proceeds through nine main stages, beginning with the identification of the medial sulci and gyri and continuing with the sequential removal of cortical layers and white matter bundles. This systematic approach exposes the cingulum, inferior longitudinal fasciculus, callosal fibers, hippocampal formation, tapetum, thalamic peduncles, and mammillothalamic tract, illustrating the organization of the limbic lobe and the relationships between major white matter tracts and the ventricular walls. Conclusion: This work presents a comprehensive and didactic video demonstration of the medial hemispheric white matter dissection, highlighting the continuity and spatial relationships of limbic and periventricular structures. It contributes to a systematic and anatomically grounded understanding of cerebral white matter organization and supports the educational role of white matter microdissection in neurosurgical anatomy.

BACKGROUND AND OBJECTIVES: Cerebrospinal fluid (CSF) leakage remains a common and clinically significant complication following skull base surgery, particularly with the translabyrinthine approach for cerebellopontine (CP) angle tumor resection. We aimed to evaluate the safety and efficacy of Foamagen in CP angle tumor resection performed through the translabyrinthine approach. METHODS: Patients undergoing CP angle tumor resection using the translabyrinthine approach were categorized into 2 groups based on the dural closure material: the intervention group received Foamagen, whereas the control group received the standard sealant DuraSeal (Integra LifeSciences). Outcomes included CSF leakage (wound leak or rhinorrhea), surgical site infection, need for lumbar drainage, and reoperation at discharge and at 3-month follow-up. RESULTS: Among 40 patients, 18 were assigned to the Foamagen group and 22 to the DuraSeal group. Baseline characteristics were comparable between the groups. At discharge, the incidence of CSF leakage was low and similar in both groups [5.6% (95% CI: 0.1%-27.3%) vs 4.5% (95% CI: 0.1%-22.8%); risk difference +1.0% (95% CI: −12.7% to +14.7%), P = 1.000]. No significant differences were observed in postoperative infection (5.6% vs 4.5%, P = 1.000), lumbar drain placement (11.1% vs 4.5%, P = .579), or reoperation rates (0% vs 4.5%, P = .369). At the 3-month follow-up, no CSF leakage or abnormal dural thickening was identified in either group. CONCLUSION: In this small exploratory cohort, Foamagen demonstrated outcomes comparable with those of the standard sealant DuraSeal. Foamagen may therefore serve as a safe and effective alternative for preventing CSF leakage following CP angle tumor resection. However, the study was substantially underpowered to establish noninferiority, and larger prospective studies are warranted to confirm this observation.