Background: This preliminary study evaluates the safety and efficacy of CyberKnife radiosurgery(CKRS) for large-volume meningiomas (≥10 cm3 ), where surgical options may be limited due to tumor location or patient health conditions. Methods: We retrospectively analyzed 18 patients with meningiomas treated with CKRS atGyeongsang National University Hospital between 2010 and 2020. Tumor control and survival rates were evaluated, with follow-up imaging performed regularly. Results: CKRS achieved a 5-year overall survival rate of 92.3% and a 5-year tumor controlrate of 93.8%. Symptomatic peritumoral edema occurred in 61.1% of patients, with 16.7% requiring surgical intervention. Conclusion CKRS appears to be a promising option for patients with large meningiomas, show-ing good tumor control and manageable complications. Further studies with larger cohorts are necessary to confirm these findings.

Background: This preliminary study evaluates the safety and efficacy of CyberKnife radiosurgery(CKRS) for large-volume meningiomas (≥10 cm3 ), where surgical options may be limited due to tumor location or patient health conditions. Methods: We retrospectively analyzed 18 patients with meningiomas treated with CKRS atGyeongsang National University Hospital between 2010 and 2020. Tumor control and survival rates were evaluated, with follow-up imaging performed regularly. Results: CKRS achieved a 5-year overall survival rate of 92.3% and a 5-year tumor controlrate of 93.8%. Symptomatic peritumoral edema occurred in 61.1% of patients, with 16.7% requiring surgical intervention. Conclusion CKRS appears to be a promising option for patients with large meningiomas, show-ing good tumor control and manageable complications. Further studies with larger cohorts are necessary to confirm these findings.

Background: This preliminary study evaluates the safety and efficacy of CyberKnife radiosurgery(CKRS) for large-volume meningiomas (≥10 cm3 ), where surgical options may be limited due to tumor location or patient health conditions. Methods: We retrospectively analyzed 18 patients with meningiomas treated with CKRS atGyeongsang National University Hospital between 2010 and 2020. Tumor control and survival rates were evaluated, with follow-up imaging performed regularly. Results: CKRS achieved a 5-year overall survival rate of 92.3% and a 5-year tumor controlrate of 93.8%. Symptomatic peritumoral edema occurred in 61.1% of patients, with 16.7% requiring surgical intervention. Conclusion CKRS appears to be a promising option for patients with large meningiomas, show-ing good tumor control and manageable complications. Further studies with larger cohorts are necessary to confirm these findings.

Meningiomas are the most common primary brain tumors in adults. The treatment of non-benign meningiomas remains a challenging task, and after the publication of the 2021 World Health Organization classification, the importance of molecular biological classification is emerging. In this article, we introduce the mechanisms of brain invasion in atypical meningioma and review the genetic factors involved along with epigenetic regulation. First, it is important to understand the three major steps for brain invasion of meningeal cells: 1) degradation of extracellular matrix by proteases, 2) promotion of tumor cell migration to resident cells by adhesion molecules, and 3) neovascularization and supporting cells by growth factors. Second, the genomic landscape of meningiomas should be analyzed by major categories, such as germline mutations in NF2 and somatic mutations in non-NF2 genes (TRAF7, KLF4, AKT1, SMO, and POLR2A). Finally, epigenetic alterations in meningiomas are being studied, with a focus on DNA methylation, histone modification, and RNA interference. Increasing knowledge of the molecular landscape of meningiomas has allowed the identification of prognostic and predictive markers that can guide therapeutic decision-making processes and the timing of follow-up.

BACKGROUND: Tumors with cysts often correlate with gliomas, metastatic tumors, or hemangioblastomas, which require differentiation. METHODS: Thirty-eight cases of cyst associated-meningioma based on preoperative radiologic studies and histologic confirmations were reviewed from November 1998 to July 2017. RESULTS: A total of 395 cases of meningioma were observed in the 20 years, and surgical treatment of intracranial meningioma was performed in 120 cases. Thirty-eight (9.6%) cases of cyst associated meningiomas were analyzed. Nauta type I was the most common type of cyst (39.5%) and the most frequent histopathological subtype was meningothelial type (36.8%). CONCLUSION: Statistically there were no significant associations between meningioma histopathological type and associated cysts; however, the rate of World Health Organization grade II was higher in cyst associated meningiomas than in unrelated meningiomas. This correlation was weak, in accordance with the meningioma grade.
Glioma ; Hemangioblastoma ; Meningioma* ; Neuropathology ; World Health Organization

Background: High-grade glioma (HGG) with primary leptomeningeal seeding (PLS) at initial diagnosis is rare. The purpose of this study was to identify its clinical features and to describe the clinical treatment outcomes. Methods: We retrospectively reviewed the medical records of patients with HGG (World Health Organization grade III or IV) at our institution between 2004 and 2019, and patients with PLS at the initial diagnosis were enrolled in the study. Clinical features, such as the location of leptomeningeal seeding, surgical methods, and degree of resection, were sorted based on electronic medical records also containing performance scale, and hematological and serological evaluations. Radiological findings and immunohistochemical categories were confirmed. Furthermore, we sought to determine whether controlling intracranial pressure (ICP) via early cerebrospinal fluid (CSF) diversion increases overall survival (OS) after the initial diagnosis. Results: Of the 469 patients with HGG in our institution, less than 2% had PLS at the initial diagnosis. Most patients suffered from headache, diplopia, and dizziness. Pathological findings included 7 glioblastomas and 2 anaplastic astrocytomas. Seven of the 9 patients underwent CSF diversion. All patients were administered concurrent chemoradiotherapy (CCRT) with temozolomide, 89% of which started adjuvant temozolomide and 33% of which completed the six cycles of adjuvant temozolomide.The OS of patients with HGG and PLS was 8.7 months (range, 4-37), an extremely poor result compared to that of other studies. Also, the 1-year and 2-year OS rates were 44.4% and 16.7%, respectively. Conclusion Diagnosis and treatment of HGG with PLS are challenging. Aggressive control of ICP followed by early initiation of standard CCRT seems to be helpful in improving symptoms. However, despite aggressive treatment, the prognosis is poor. A multicenter trial and research may be necessary to create a standardized protocol for this disease.

Background: This study analyzed the epidemiology and treatment outcomes of germ cell tumorpatients at a single institution. Methods: A retrospective analysis was conducted on intracranial germ cell tumor (iGCT) pa-tients treated at a single tertiary hospital from 2004 to 2019. Patients were categorized based on treatment modality: Korean Society for Pediatric Neuro-Oncology (KSPNO) protocol or bleomycin, etoposide, and cisplatin with radiation therapy. Results: Forty-nine iGCT patients treated with combined chemotherapy and radiotherapywere analyzed. The median age was 19 years (range: 6–40), with a median follow-up duration of 148.0 months (range: 10.5–265.5). Tumors were most common in the pineal gland (51.0%). Although no significant differences in outcomes were observed between treatment modalities, outcomes varied significantly by pathological type. The 10-year progression-free survival rates for germinoma and non-germinomatous germ cell tumors (NGGCTs) were 88.1% and 32.7%, respectively (p=0.003), while the 10-year overall survival rates were 92.9% and 67.5%, respectively (p<0.001). Fourteen patients experienced CTCAE (Common Terminology Criteria for Adverse Events) grade ≥3 adverse events, with one eventrelated death. Conclusion Pure germinoma demonstrated higher survival and lower recurrence rates comparedto NGGCT. The KSPNO protocol appears to be an acceptable and safe treatment option for iGCT patients. Further multi-institutional studies with larger cohorts are warranted.

Objective: : Although Republic of Korea is an advanced country in medical technology with a successful treatment rate for serious diseases, such as cancer, and has improved technology for highly difficult surgery, many excellent medical doctors and physicians are struggling due to the recent unreasonable medical environment. Specialization in brain tumor surgery also faces challenges in Republic of Korea, including low financial incentives, legal threats, and limited career prospects. In response, the Korean Brain Tumor Society (KBTS) formed the Future Strategy Committee to assess these obstacles and propose solutions. Methods: : A survey was conducted among the KBTS members to understand their perceptions and concerns across different career stages. Results: : The findings revealed a decline in interest among chief residents in brain tumor surgery, owing to limited job opportunities and income prospects. Neurosurgical fellows expressed neutral satisfaction but highlighted challenges, such as low patient numbers and income. Faculty members with varying levels of experience echoed similar concerns, emphasizing the need for improved financial incentives and job stability. Despite these challenges, the respondents expressed dedication to the field and suggested strategies for improvement. Conclusion : The KBTS outlines a vision that focuses on practical excellence, comprehensive research, professional education, responsibilities, and member satisfaction. Addressing these challenges requires collaborative efforts among healthcare institutions, professional societies, and policymakers to support brain tumor specialists and enhance patient care.

Objective: : Although Republic of Korea is an advanced country in medical technology with a successful treatment rate for serious diseases, such as cancer, and has improved technology for highly difficult surgery, many excellent medical doctors and physicians are struggling due to the recent unreasonable medical environment. Specialization in brain tumor surgery also faces challenges in Republic of Korea, including low financial incentives, legal threats, and limited career prospects. In response, the Korean Brain Tumor Society (KBTS) formed the Future Strategy Committee to assess these obstacles and propose solutions. Methods: : A survey was conducted among the KBTS members to understand their perceptions and concerns across different career stages. Results: : The findings revealed a decline in interest among chief residents in brain tumor surgery, owing to limited job opportunities and income prospects. Neurosurgical fellows expressed neutral satisfaction but highlighted challenges, such as low patient numbers and income. Faculty members with varying levels of experience echoed similar concerns, emphasizing the need for improved financial incentives and job stability. Despite these challenges, the respondents expressed dedication to the field and suggested strategies for improvement. Conclusion : The KBTS outlines a vision that focuses on practical excellence, comprehensive research, professional education, responsibilities, and member satisfaction. Addressing these challenges requires collaborative efforts among healthcare institutions, professional societies, and policymakers to support brain tumor specialists and enhance patient care.

Background: This study analyzed the epidemiology and treatment outcomes of germ cell tumorpatients at a single institution. Methods: A retrospective analysis was conducted on intracranial germ cell tumor (iGCT) pa-tients treated at a single tertiary hospital from 2004 to 2019. Patients were categorized based on treatment modality: Korean Society for Pediatric Neuro-Oncology (KSPNO) protocol or bleomycin, etoposide, and cisplatin with radiation therapy. Results: Forty-nine iGCT patients treated with combined chemotherapy and radiotherapywere analyzed. The median age was 19 years (range: 6–40), with a median follow-up duration of 148.0 months (range: 10.5–265.5). Tumors were most common in the pineal gland (51.0%). Although no significant differences in outcomes were observed between treatment modalities, outcomes varied significantly by pathological type. The 10-year progression-free survival rates for germinoma and non-germinomatous germ cell tumors (NGGCTs) were 88.1% and 32.7%, respectively (p=0.003), while the 10-year overall survival rates were 92.9% and 67.5%, respectively (p<0.001). Fourteen patients experienced CTCAE (Common Terminology Criteria for Adverse Events) grade ≥3 adverse events, with one eventrelated death. Conclusion Pure germinoma demonstrated higher survival and lower recurrence rates comparedto NGGCT. The KSPNO protocol appears to be an acceptable and safe treatment option for iGCT patients. Further multi-institutional studies with larger cohorts are warranted.