Purpose: Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT. Materials and Methods: This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Results: Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised. Conclusion Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.

Background: As one of the most challenging fractures to orthopedic surgeons, acetabular fractures show a wide range of incidence among countries and regions with even more variance in the treatment modalities. In this study, we aimed to investigate the epidemiology of acetabular fractures, and to compare the rate of subsequent total hip arthroplasty (THA) between nonoperative and operative treatments in South Korea using a medical claims database. Methods: This was a retrospective study using the Korean Health Insurance Review and Assessment database. Patients admitted for acetabular fractures from January 2007 to December 2018 were identified using International Classification of Diseases-10 codes.Kaplan-Meier survival analysis was used to compare the cumulative incidence of THA between two groups. We also evaluated the survivorship of operative group according to the type of institutions. Results: The incidence rate of acetabular fractures increased by 28% between 2007 and 2018. Acetabular fractures were more common in men (62%) than women (38%), and most common in the patients older than 80 years. The number of acetabular fractures was estimated to increase 1.7-fold in 2030 compared to 2018. Operative treatment accounted for 16% of cases, and nonoperative treatment for 84%. The incidence of subsequent THA was higher in the operative treatment group than in the nonoperative group (P < 0.001).The higher rate in the operative treatment group is probably related with the severity of the fracture type. The rate of subsequent THA was higher in patients who initially treated in general hospitals compared with those who were initially treated in tertiary hospitals. Conclusion The incidence of acetabular fractures is increasing in South Korea, in line with global trends. Most acetabular fractures are treated conservatively, and those who receive surgery are more likely to require a subsequent THA. Patients who were operated in general hospitals had highest possibility of subsequent THA after acetabular fractures.

Purpose: This study aimed to evaluate the role of postoperative radiotherapy (PORT) in intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC). Materials and Methods: A total of 133 patients with histologically confirmed HPC were included from eight institutions. Gross total resection (GTR) and subtotal resection (STR) were performed in 86 and 47 patients, respectively. PORT was performed in 85 patients (64%). The prognostic effects of sex, age, performance, World Health Organization (WHO) grade, location, size, Ki-67, surgical extent, and PORT on local control (LC), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS) were estimated by univariate and multivariate analyses. Results: The 10-year PFS, and OS rates were 45%, and 71%, respectively. The multivariate analysis suggested that PORT significantly improved LC (p < 0.001) and PFS (p < 0.001). The PFS benefit of PORT was maintained in the subgroup of GTR (p=0.001), WHO grade II (p=0.001), or STR (p < 0.001). In the favorable subgroup of GTR and WHO grade II, PORT was also significantly related to better PFS (p=0.028). WHO grade III was significantly associated with poor DMFS (p=0.029). In the PORT subgroup, the 0-0.5 cm margin of the target volume showed an inferior LC to a large margin with 1.0-2.0 cm (p=0.021). Time-dependent Cox proportion analysis showed that distant failures were significantly associated with poor OS (p=0.003). Conclusion This multicenter study supports the role of PORT in disease control of intracranial SFT/HPC, irrespective of the surgical extent and grade. For LC, PORT should enclose the tumor bed with sufficient margin.

Background: To date, there has been no practical guidelines for the prescription of antiepileptic drugs (AEDs) in brain tumor patients in Korea. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, had begun preparing guidelines for AED usage in brain tumors since 2019. Methods: The Working Group was composed of 27 multidisciplinary medical experts in Korea.References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of the keywords. Results: The core contents are as follows. Prophylactic AED administration is not recommended in newly diagnosed brain tumor patients without previous seizure history. When AEDs are administered during peri/postoperative period, it may be tapered off according to the following recommendations. In seizure-naïve patients with no postoperative seizure, it is recommended to stop or reduce AED 1 week after surgery. In seizure-naïve patients with one early postoperative seizure (<1 week after surgery), it is advisable to maintain AED for at least 3 months before tapering. In seizure-naïve patients with ≥2 postoperative seizures or in patients with preoperative seizure history, it is recommended to maintain AEDs for more than 1 year. The possibility of drug interactions should be considered when selecting AEDs in brain tumor patients. Driving can be allowed in brain tumor patients when proven to be seizure-free for more than 1 year. Conclusion The KSNO suggests prescribing AEDs in patients with brain tumor based on the current guideline. This guideline will contribute to spreading evidence-based prescription of AEDs in brain tumor patients in Korea.

Background: There have been no guidelines for the management of adult patients with diffuse midline glioma (DMG), H3K27M-mutant in Korea since the 2016 revised WHO classification newly defined this disease entity. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, had begun preparing guidelines for DMG since 2019. Methods: The Working Group was composed of 27 multidisciplinary medical experts in Korea.References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of keywords. As ‘diffuse midline glioma’ was recently defined, and there was no international guideline, trials and guidelines of ‘diffuse intrinsic pontine glioma’ or ‘brain stem glioma’ were thoroughly reviewed first. Results: The core contents are as follows. The DMG can be diagnosed when all of the following three criteria are satisfied: the presence of the H3K27M mutation, midline location, and infiltrating feature. Without identification of H3K27M mutation by diagnostic biopsy, DMG cannot be diagnosed. For the primary treatment, maximal safe resection should be considered for tumors when feasible. Radiotherapy is the primary option for tumors in case the total resection is not possible. A total dose of 54 Gy to 60 Gy with conventional fractionation prescribed at 1-2 cm plus gross tumor volume is recommended. Although no chemotherapy has proven to be effective in DMG, concurrent chemoradiotherapy (± maintenance chemotherapy) with temozolomide following WHO grade IV glioblastoma’s protocol is recommended. Conclusion The detection of H3K27M mutation is the most important diagnostic criteria for DMG. Combination of surgery (if amenable to surgery), radiotherapy, and chemotherapy based on comprehensive multidisciplinary discussion can be considered as the treatment options for DMG.

Background: To date, there has been no practical guidelines for the prescription of antiepileptic drugs (AEDs) in brain tumor patients in Korea. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, had begun preparing guidelines for AED usage in brain tumors since 2019. Methods: The Working Group was composed of 27 multidisciplinary medical experts in Korea.References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of the keywords. Results: The core contents are as follows. Prophylactic AED administration is not recommended in newly diagnosed brain tumor patients without previous seizure history. When AEDs are administered during peri/postoperative period, it may be tapered off according to the following recommendations. In seizure-naïve patients with no postoperative seizure, it is recommended to stop or reduce AED 1 week after surgery. In seizure-naïve patients with one early postoperative seizure (<1 week after surgery), it is advisable to maintain AED for at least 3 months before tapering. In seizure-naïve patients with ≥2 postoperative seizures or in patients with preoperative seizure history, it is recommended to maintain AEDs for more than 1 year. The possibility of drug interactions should be considered when selecting AEDs in brain tumor patients. Driving can be allowed in brain tumor patients when proven to be seizure-free for more than 1 year. Conclusion The KSNO suggests prescribing AEDs in patients with brain tumor based on the current guideline. This guideline will contribute to spreading evidence-based prescription of AEDs in brain tumor patients in Korea.

Background: There have been no guidelines for the management of adult patients with diffuse midline glioma (DMG), H3K27M-mutant in Korea since the 2016 revised WHO classification newly defined this disease entity. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, had begun preparing guidelines for DMG since 2019. Methods: The Working Group was composed of 27 multidisciplinary medical experts in Korea.References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of keywords. As ‘diffuse midline glioma’ was recently defined, and there was no international guideline, trials and guidelines of ‘diffuse intrinsic pontine glioma’ or ‘brain stem glioma’ were thoroughly reviewed first. Results: The core contents are as follows. The DMG can be diagnosed when all of the following three criteria are satisfied: the presence of the H3K27M mutation, midline location, and infiltrating feature. Without identification of H3K27M mutation by diagnostic biopsy, DMG cannot be diagnosed. For the primary treatment, maximal safe resection should be considered for tumors when feasible. Radiotherapy is the primary option for tumors in case the total resection is not possible. A total dose of 54 Gy to 60 Gy with conventional fractionation prescribed at 1-2 cm plus gross tumor volume is recommended. Although no chemotherapy has proven to be effective in DMG, concurrent chemoradiotherapy (± maintenance chemotherapy) with temozolomide following WHO grade IV glioblastoma’s protocol is recommended. Conclusion The detection of H3K27M mutation is the most important diagnostic criteria for DMG. Combination of surgery (if amenable to surgery), radiotherapy, and chemotherapy based on comprehensive multidisciplinary discussion can be considered as the treatment options for DMG.

Background: : The Guideline Working Group of the Korean Society for Neuro-Oncology (KSNO)conducted the nationwide questionnaire survey for diverse queries facing to treat patients with braintumor. As part III of the survey, the aim of this study is to evaluate the national patterns of clinical practicefor patients with brain metastasis and primary central nervous system lymphoma (PCNSL). Methods: : A web-based survey was sent to all members of the KSNO by email. The survey included7 questions of brain metastasis and 5 questions of PCNSL, focused on the management strategiesin specific situations. All questions were developed by consensus of the Guideline WorkingGroup. Results: " In the survey about brain metastasis, respondents preferred surgical resection withadjuvant treatment for patients with a surgically accessible single brain metastatic lesion less than 3cm in size without extracranial systemic lesions. However, most respondents considered radiosurgeryfor surgically inaccessible lesions. As the preferred treatment of multiple brain metastases according tothe number of brain lesions, respondents tended to choose radiotherapy with increasing number of lesions.Radiosurgery was mostly chosen for the brain metastases of less than or equal to 4. In the surveyabout PCNSL, a half of respondents choose high-dose methotrexate-based polychemotherapy asthe first-line induction therapy for PCNSL. The consolidation and salvage therapy showed a little variationamong respondents. For PCNSL patients with cerebrospinal fluid dissemination, intrathecal chemotherapywas most preferred. Conclusion : The survey demonstrates the prevailing clinical practice patterns for patients withbrain metastasis and PCNSL among members of the KSNO. This information provides a point of referencefor establishing a practical guideline in the management of brain metastasis and PCNSL.

Background: : The Guideline Working Group of the Korean Society for Neuro-Oncology (KSNO)conducted a nationwide questionnaire survey for diverse queries faced in the treatment of brain tumors.As part I of the survey, the aim of this study is to evaluate national patterns of clinical practiceabout antiepileptic drug (AED) and steroid usage for management of brain tumors. Methods: : A web-based survey was sent to all members of the KSNO by email. The survey included9 questions of AED usage and 5 questions of steroid usage for brain tumor patients. All questionswere developed by consensus of the Guideline Working Group. Results: : The overall response rate was 12.8% (54/423). Regarding AED usage, the majority ofrespondents (95.2%) routinely prescribed prophylactic AEDs for patients with seizure at the peri/postoperativeperiod. However, as many as 72.8% of respondents prescribed AED routinely for seizure-naïvepatients, and others prescribed AED as the case may be. The duration of AED prophylaxis showedwide variance according to the epilepsy status and the location of tumor. Levetiracetam (82.9%) wasthe most preferred AED for epilepsy prophylaxis. Regarding steroid usage, 90.5% of respondents usesteroids in perioperative period, including 34.2% of them as a routine manner. Presence of peritumoraledema (90.9%) was considered as the most important factor determining steroid usage followed bydegree of clinical symptoms (60.6%). More than half of respondents (51.2%) replied to discontinue thesteroids within a week after surgery if there are no specific medical conditions, while 7.3% preferredslow tapering up to a month after surgery. Conclusion : The survey demonstrated the prevailing practice patterns on AED and steroid usagein neuro-oncologic field among members of the KSNO. This information provides a point of referencefor establishing a practical guideline in the management of brain tumor patients.

Background: : The Guideline Working Group of the Korean Society for Neuro-Oncology (KSNO)conducted a nationwide questionnaire survey for diverse queries faced in the treatment of brain tumors.As part II of the survey, the aim of this study is to evaluate the national patterns of clinical practicefor patients with diffuse midline glioma and meningioma. Methods: : A web-based survey was sent to all members of the KSNO by email. The survey included4 questions of diffuse midline glioma and 6 questions of meningioma (including 2 case scenarios).All questions were developed by consensus of the Guideline Working Group. Results: : In the survey about diffuse midline glioma, 76% respondents performed histologicconfirmation to identify H3K27M mutation on immunohistochemical staining or sequencing methods.For treatment of diffuse midline glioma, respondents preferred concurrent chemoradiotherapy withtemozolomide (TMZ) and adjuvant TMZ (63.8%) than radiotherapy alone (34.0%). In the surveyabout meningioma, respondents prefer wait-and-see policy for the asymptomatic small meningiomawithout peritumoral edema. However, a greater number of respondents had chosen surgical resectionas the first choice for all large size meningiomas without exception, and small size meningiomaswith either peritumoral edema or eloquent location. There was no single opinion with major consensuson long-term follow-up plans for asymptomatic meningioma with observation policy. As many as68.1% of respondents answered that they would not add any adjuvant therapies for World Health Organizationgrade II meningiomas if the tumor was totally resected including dura. Conclusion : The survey demonstrates the prevailing clinical practice patterns for patients with diffusemidline glioma and meningioma among members of the KSNO. This information provides a pointof reference for establishing a practical guideline in the management of diffuse midline glioma andmeningioma.