Impact of upfront adjuvant chemoradiation on survival in patients with molecularly defined oligodendroglioma: the benefits of PCV over TMZ.

PURPOSE: Oligodendroglioma is an adult-type diffuse glioma defined by 1p/19q codeletion and IDH1/2 mutation. Treatment includes surgery followed by observation alone in select low-grade tumors, or combination radiation and chemotherapy with procarbazine, lomustine, and vincristine (PCV) or temozolomide (TMZ). While prospective studies investigating treatments for molecularly defined oligodendrogliomas are ongoing, this retrospective study analyzes the relationship between adjuvant regimens and progression-free survival (PFS). METHODS: Adults with IDH-mutant, 1p/19q codeleted oligodendroglioma (WHO grade 2 or 3) who underwent surgery between 2005 and 2021 were identified. Clinical data, disease characteristics, treatment, and outcomes were collected. RESULTS: A total of 207 patients with grade 2 and 70 with grade 3 oligodendrogliomas were identified. Median (IQR) follow-up was 57 (87) months. Patients with grade 3 tumors who received adjuvant radiation and PCV had longer median PFS (> 110 months) than patients who received radiation and TMZ (52 months, p = 0.008) or no adjuvant chemoradiation (83 months, p = 0.03), which was not seen in grade 2 tumors (p = 0.8). In multivariate analysis, patients who received PCV chemotherapy (Relative Risk [95% CI] = 0.24[0.05-1.08] and radiotherapy (0.46[0.21-1.02]) trended towards longer PFS, independently of grade. CONCLUSION: Adjuvant radiation and PCV are associated with improved PFS over radiation with TMZ in patients with grade 3 molecularly defined oligodendrogliomas, and all-grade patients treated with PCV trended towards decreased risk of recurrence and progression. These results highlight the importance of ongoing clinical trials investigating these treatments.

Radiation immunodynamics in patients with glioblastoma receiving chemoradiation.

Introduction: This is a prospective, rigorous inquiry into the systemic immune effects of standard adjuvant chemoradiotherapy, for WHO grade 4, glioblastoma. The purpose is to identify peripheral immunologic effects never yet reported in key immune populations, including myeloid-derived suppressor cells, which are critical to the immune suppressive environment of glioblastoma. We hypothesize that harmful immune-supportive white blood cells, myeloid derived suppressor cells, expand in response to conventionally fractionated radiotherapy with concurrent temozolomide, essentially promoting systemic immunity similar what is seen in chronic diseases like diabetes and heart disease. Methods: 16 patients were enrolled in a single-institution, observational, immune surveillance study where peripheral blood was collected and interrogated by flow cytometry and RNAseq. Tumor tissue from baseline assessment was analyzed with spatial proteomics to link peripheral blood findings to baseline tissue characteristics. Results: We identified an increase in myeloid-derived suppressor cells during the final week of a six-week treatment of chemoradiotherapy in peripheral blood of patients that were not alive at two years after diagnosis compared to those who were living. This was also associated with a decrease in CD8+ T lymphocytes that produced IFNγ, the potent anti-tumor cytokine. Discussion: These data suggest that, as in chronic inflammatory disease, systemic immunity is impaired following delivery of adjuvant chemoradiotherapy. Finally, baseline investigation of myeloid cells within tumor tissue did not differ between survival groups, indicating immune surveillance of peripheral blood during adjuvant therapy may be a critical missing link to educate our understanding of the immune effects of standard of care therapy for glioblastoma.

Radiosurgery Society Case-Based Guide to Stereotactic Body Radiation Therapy for Challenging Cases of Spinal Metastases.

PURPOSE: Spinal stereotactic body radiation therapy (SBRT) has become the standard of care in management of patients with limited sites of metastatic disease, radioresistant histologies, painful vertebral metastases with long life expectancy and cases of reirradiation. Our case-based guidelines aim to assist radiation oncologists in the appropriate utilization of SBRT for common, yet challenging, cases of spinal metastases. METHODS AND MATERIALS: Cases were selected to include scenarios of large volume sacral disease with nerve entrapment, medically inoperable disease abutting the thecal sac, and local failure after prior SBRT. Relevant literature was reviewed, and areas requiring further investigation were discussed to offer a framework for evidence-based clinical practice. RESULTS: Spinal SBRT can be effectively delivered in challenging cases following multidisciplinary discussion by using a methodical approach to patient selection, appropriate dose selection, and adherence to evidence-based dose constraints. CONCLUSIONS: The Radiosurgery Society's case-based practice review offers guidance to practicing physicians treating technically challenging SBRT candidate patients with spinal metastases.

Survival Factors in 1580 Adults with Spinal Ependymoma: Insights from a Multicenter Oncology Database.

BACKGROUND: Using a multi-institutional oncology database, we investigate the survival rates and the impacts of demographic, clinical, and management characteristics on overall survival among adult patients diagnosed with spinal ependymoma. METHODS: Utilizing the SEER registry, patients with histologically or radiologically confirmed ependymomas were included. Factors impacting overall survival were analyzed using Kaplan-Meier survival curves and log-rank statistical analyses. RESULTS: A total of 1,580 patients were included. Their mean ± standard deviation age was 46.68 ± 15.96 years, and 51.1% were women. Gross total resection (GTR) was achieved in 66.4% of patients. The 5- and 10-year survival rates were 96.7% and 95.4%, respectively. A multivariable backward Cox regression showed that age ≥65 years was a significant predictor for mortality (hazard ratio [HR]: 3.93; 95% confidence interval [CI]: 2.21-7.00; P < 0.001). Likewise, tumor grade 3 (HR: 6.36; 95% CI: 1.95-20.76; P = 0.002), tumor grade 4 (HR: 7.74; 95% CI: 3.97-15.11; P < 0.001), presence of extra-neural metastasis (HR: 13.81; 95% CI: 3.67-51.96; P < 0.001), and receiving radiotherapy (HR: 2.50; 95% CI: 1.50-4.19; P < 0.001) were significant risk factors for mortality, while GTR was significantly associated with improved overall survival compared with subtotal resection or nonsurgical management (HR: 0.42; 95% CI: 0.25-0.73; P = 0.002). There were no significant effects for gender, race, marital status, income, residential area, chemotherapy, tumor size, and the presence of other benign or malignant tumors on the survival hazards (P > 0.05 for each). CONCLUSION: Early diagnosis and surgical management of spinal ependymomas, such as GTR, were associated with remarkable survival benefits. Old age, high-grade spinal ependymoma, and extra-neural metastasis were associated with worse overall survival, whereas radiotherapy's role remains unclear.

Outcomes After Definitive Surgery for Spinal and Sacral Chordoma in 101 Patients Over 20 Years.

BACKGROUND AND OBJECTIVES: Spinal chordomas are primary bone tumors where surgery remains the primary treatment. However, their low incidence, lack of evidence, and late disease presentation make them challenging to manage. Here, we report the postoperative outcomes of a large cohort of patients after surgical resection, investigate predictors for overall survival (OS) and local recurrence-free survival (LRFS) times, and trend functional outcomes over multiple time periods. METHODS: Retrospective review of all patients followed for spinal chordoma at a quaternary spinal oncology center from 2003 to 2023 was included. Data were collected regarding demographics, preoperative and perioperative management, and follow-up since initial definitive surgery. Primary outcomes were OS and LRFS, whereas secondary outcomes were functional deficits. RESULTS: One hundred one patients had an average follow-up of 6.0 ± 4.2 years. At the time of census, 25/101 (24.8%) had experienced a recurrence and 10/101 (9.9%) had died. After surgery, patients experienced a significant decrease in pain over time, but rates of sensory deficits, weakness, and bowel/bladder dysfunction remained static. Tumors ≥100 cm3 (hazard ratio (HR) = 5.89, 95% CI 1.72-20.18, P = .005) and mobile spine chordomas (HR = 7.73, 95% CI 2.09-28.59, P = .002) are related to worse LRFS, whereas having neoadjuvant radiotherapy is associated with improved LRFS (HR = 0.09, 95% CI 0.01-0.88, P = .038). On the other hand, being age ≥65 years was associated with decreased OS (HR = 16.70, 95% CI 1.54-181.28, P = .021). CONCLUSION: Surgeons must often weigh the pros and cons of en bloc resection and sacrificing important but affected native tissues. Our findings can provide a benchmark for counseling patients with spinal chordoma. Tumors ≥100 cm3 appear to have a 5.89-times higher risk of recurrence, mobile spine chordomas have a 7.73 times higher risk, and neoadjuvant radiotherapy confers an 11.1 times lower risk for local recurrence. Patients age ≥65 years at surgery have a 16.70 times higher risk of mortality than those <65 years.

Genomic Alterations in Molecularly Defined Oligodendrogliomas.

BACKGROUND AND OBJECTIVES: Oligodendrogliomas are defined by IDH1/2 mutation and codeletion of chromosome arms 1p/19q. Although previous studies identified CIC, FUBP1, and TERTp as frequently altered in oligodendrogliomas, the clinical relevance of these molecular signatures is unclear. Moreover, previous studies predominantly used research panels that are not readily available to providers and patients. Accordingly, we explore genomic alterations in molecularly defined oligodendrogliomas using clinically standardized next-generation sequencing (NGS) panels. METHODS: A retrospective single-center study evaluated adults with pathologically confirmed IDH-mutant, 1p/19q-codeleted oligodendrogliomas diagnosed between 2005 and 2021. Genetic data from formalin-fixed, paraffin-embedded specimens were analyzed with the NGS Solid Tumor Panel at the Johns Hopkins Medical Laboratories, which tests more than 400 cancer-related genes. Kaplan-Meier plots and log-rank tests compared progression-free survival (PFS) and overall survival by variant status. χ2 tests, t-tests, and Wilcoxon rank-sum tests were used to compare clinical characteristics between genomic variant status in the 10 most frequently altered genes. RESULTS: Two hundred and seventy-seven patients with molecularly defined oligodendrogliomas were identified, of which 95 patients had available NGS reports. Ten genes had 9 or more patients with a genomic alteration, with CIC, FUBP1, and TERTp being the most frequently altered genes (n = 60, 23, and 22, respectively). Kaplan-Meier curves showed that most genes were not associated with differences in PFS or overall survival. At earlier time points (PFS <100 months), CIC alterations conferred a reduction in PFS in patients (P = .038). CONCLUSION: Our study confirms the elevated frequency of CIC, FUBP1, and TERTp alterations in molecularly defined oligodendrogliomas and suggests a potential relationship of CIC alteration to PFS at earlier time points. Understanding these genomic variants may inform prognosis or therapeutic recommendations as NGS becomes routine.

A Case-based Guide for World Health Organization (WHO) Grade 2 Meningioma Radiosurgery and Radiation Therapy from The Radiosurgery Society.

PURPOSE: Meningiomas represent the most common primary tumor of the central nervous system. Current treatment options include surgical resection with or without adjuvant radiation therapy (RT), definitive RT, and observation. However, the radiation dose, fractionation, and margins used to treat patients with WHO grade 2 meningiomas, which account for approximately 20% of all meningiomas, are not clearly defined, and deciding on the optimal treatment modality can be challenging owing to the lack of randomized data. METHODS AND MATERIALS: In this manuscript, 3 cases of patients with WHO grade 2 meningiomas are presented with descriptions of treatment options after gross total resection, subtotal resection, and previous irradiation. Treatment recommendations were compiled from 9 central nervous system radiation oncology and neurosurgery experts from The Radiosurgery Society, and the consensus of treatment recommendations is reported. RESULTS: Both conventional and stereotactic RT are treatment options for WHO grade 2 meningiomas. The majority of prospective data in the setting of WHO grade 2 meningiomas involve larger margins. Stereotactic radiosurgery/hypofractionated stereotactic RT are less appropriate in this setting. Conventionally fractionated RT to at least 59.4 Gy is considered standard of care with utilization of preoperative and postoperative imaging to evaluate the extent of disease and possible osseous involvement. After careful discussion, stereotactic radiosurgery/hypofractionated stereotactic RT may play a role for the subset of patients who are unable to tolerate the standard lengthy conventionally fractionated treatment course, for those with prior RT, or for small residual tumors. However, more studies are needed to determine the optimal approach. CONCLUSIONS: This case-based evaluation of the current literature seeks to provide examples for the management of grade 2 meningiomas and give examples of both conventional and stereotactic RT.

Fractionated radiotherapy after gross-total resection of spinal chordoma: a systematic review of survival outcomes using individualized patient data.

OBJECTIVE: Spinal chordoma treatment guidelines recommend resection. However, in patients in whom gross-total resection (GTR) is achieved, the benefits of radiation therapy (RT) are unclear. Therefore, the authors performed a systematic review to determine if RT is associated with postoperative progression-free survival (PFS) or overall survival (OS) after achieving GTR of spinal chordoma. METHODS: The PubMed database was searched for studies including individualized data of patients undergoing GTR with or without RT for spinal chordoma. Patients < 18 years of age or those who underwent stereotactic body RT were excluded. Qualitative assessment was performed using Newcastle-Ottawa Scale guidelines. Log-rank tests for time-to-event data and a Cox proportional-hazards model were generated for a multivariable statistical model. RESULTS: Complete data of 132 patients were retrieved, with 37 (28%) patients receiving adjuvant RT and 95 (72%) not receiving adjuvant RT. The mean follow-up was not statistically significantly different between those undergoing RT and not undergoing RT (54.02 months and 65.43 months, respectively). Patients were more likely not to undergo RT if their disease was located in the sacrum versus the mobile spine (p < 0.001). When controlling for age ≥ 65 years, male sex, disease location, and treatment year ≥ 2010, patients undergoing RT had similar PFS and OS when compared with those not undergoing RT on multivariable survival analysis (HR 0.935 [95% CI 0.703-2.340], p = 0.844 and HR 2.078 [95% CI 0.848-5.090], p = 0.110, respectively). However, age ≥ 65 years was associated with poorer OS in adjusted analyses (HR 2.761 [95% CI 1.185-6.432], p = 0.018) relative to patients < 65 years of age. CONCLUSIONS: After achieving GTR of spinal chordoma, the utility of RT on PFS and OS remains unclear. Age ≥ 65 years appears to be associated with OS in spinal chordoma patients. Additional multicenter prospective studies are needed to determine the utility of RT in this patient population.

Characterizing the presentation, management, and clinical outcomes of patients with intradural spinal chordomas: a systematic review.

OBJECTIVE: Chordomas are locally aggressive neoplasms of the spine or skull base that arise from embryonic remnants of the notochord. Intradural chordomas represent a rare subset of these neoplasms, and few studies have described intradural chordomas in the spine. This review evaluates the presentation, management, and outcomes of intradural spinal chordomas. METHODS: A systematic review of PubMed/MEDLINE, EMBASE, Cochrane Library, Scopus, and Web of Science was performed. Studies describing at least 1 case of intradural chordomas anywhere in the spine were included. Extracted details included presenting symptoms, radiological findings, treatment course, follow-up, and disease progression. RESULTS: Thirty-one studies, with a total of 41 patients, were included in this review. Seventy-six percent (31/41) of patients had primary intradural tumors, whereas 24% (10/41) presented with metastasis. The most common signs and symptoms were pain (n = 27, 66%); motor deficits (n = 20, 49%); sensory deficits (n = 17, 42%); and gait disturbance (n = 10, 24%). The most common treatment for intradural chordoma was resection and postoperative radiotherapy. Sixty-six percent (19/29) of patients reported improvement or complete resolution of symptoms after surgery. The recurrence rate was 37% (10/27), and the complication rate was 25% (6/24). The median progression-free survival was 24 months (range 4-72 months). Four patient deaths were reported. The median follow-up time was 12 months (range 13 days-84 months). CONCLUSIONS: Treatment of intradural spinal chordomas primarily involves resection and radiotherapy. A significant challenge and complication in management is spinal tumor seeding after resection, with 9 studies proposing seeding as a mechanism of tumor metastasis in 11 cases. Factors such as tumor size, Ki-67 positivity, and distant metastasis may correlate with worse outcomes and demonstrate potential as prognostic indicators for intradural spinal chordomas. Further research is needed to improve understanding of this tumor and develop optimal treatment paradigms for these patients.

Stereotactic body radiation therapy for spinal metastases: A new standard of care.

Advancements in systemic therapies for patients with metastatic cancer have improved overall survival and, hence, the number of patients living with spinal metastases. As a result, the need for more versatile and personalized treatments for spinal metastases to optimize long-term pain and local control has become increasingly important. Stereotactic body radiation therapy (SBRT) has been developed to meet this need by providing precise and conformal delivery of ablative high-dose-per-fraction radiation in few fractions while minimizing risk of toxicity. Additionally, advances in minimally invasive surgical techniques have also greatly improved care for patients with epidural disease and/or unstable spines, which may then be combined with SBRT for durable local control. In this review, we highlight the indications and controversies of SBRT along with new surgical techniques for the treatment of spinal metastases.

Clinical Outcomes After Stereotactic Body Radiation Therapy for Nonspinal Bone Metastases: A Systematic Review and Meta-analysis.

There are limited data available on clinical outcomes after stereotactic body radiation therapy (SBRT) for nonspinal bone metastases. We performed a systematic review and meta-analysis to characterize local control (LC), overall survival (OS), pain response rates, and toxicity after SBRT. The primary outcomes were 1-year LC, incidence of acute and late grade 3 to 5 toxicities, and overall pain response rate at 3 months. The secondary outcome was 1-year OS. The Newcastle-Ottawa scale was used for assessment of study bias, with a median score of 5 for included studies (range, 4-8). Weighted random-effects meta-analyses were conducted to estimate effect sizes. We identified 528 patients with 597 nonspinal bone lesions in 9 studies (1 prospective study and 8 retrospective observational studies) treated with SBRT. The estimated 1-year LC rate was 94.6% (95% CI, 87.0%-99.0%). The estimated 3-month combined partial and complete pain response rate after SBRT was 87.7% (95% CI, 55.1%-100.0%). The estimated combined acute and late grade 3 to 5 toxicity rate was 0.5% (95% CI, 0%-5.0%), with an estimated pathologic fracture rate of 3.1% (95% CI, 0.2%-9.1%). The estimated 1-year OS rate was 71.0% (95% CI, 51.7%-87.0%). SBRT results in excellent LC and palliation of symptoms with minimal related toxicity. Prospective investigations are warranted to further characterize long-term outcomes of SBRT for patients with nonspinal bone metastases.

Stereotactic Radiosurgery in the Management of Brain Metastases: A Case-Based Radiosurgery Society Practice Guideline.

Purpose: Brain metastases are common among adult patients with solid malignancies and are increasingly being treated with stereotactic radiosurgery (SRS). As more patients with brain metastases are becoming eligible for SRS, there is a need for practical review of patient selection and treatment considerations. Methods and Materials: Two patient cases were identified to use as the foundation for a discussion of a wide and representative range of management principles: (A) SRS alone for 5 to 15 lesions and (B) a large single metastasis to be treated with pre- or postoperative SRS. Patient selection, fractionation, prescription dose, treatment technique, and dose constraints are discussed. Literature relevant to these cases is summarized to provide a framework for treatment of similar patients. Results: Treatment of brain metastases with SRS requires many considerations including optimal patient selection, fractionation selection, and plan optimization. Conclusions: Case-based practice guidelines developed by the Radiosurgery Society provide a practical guide to the common scenarios noted above affecting patients with metastatic brain tumors.

Oncologic and Functional Outcomes After Stereotactic Body Radiation Therapy for High-Grade Malignant Spinal Cord Compression.

Purpose: Although surgical decompression is the gold standard for metastatic epidural spinal cord compression (MESCC) from solid tumors, not all patients are candidates or undergo successful surgical Bilsky downgrading. We report oncologic and functional outcomes for patients treated with stereotactic body radiation therapy (SBRT) to high-grade MESCC. Methods and Materials: Patients with Bilsky grade 2 to 3 MESCC from solid tumor metastases treated with SBRT at a single institution from 2009 to 2020 were retrospectively reviewed. Patients who received upfront surgery before SBRT were included only if postsurgical Bilsky grade remained ≥2. Neurologic examinations, magnetic resonance imaging, pain assessments, and analgesic usage were assessed every 3 to 4 months post-SBRT. Cumulative incidence of local recurrence was calculated with death as a competing risk, and overall survival was estimated by Kaplan-Meier. Results: One hundred forty-three patients were included. The cumulative incidence of local recurrence was 5.1%, 7.5%, and 14.1% at 6, 12, and 24 months, respectively. At first post-SBRT imaging, 16.2% of patients with initial Bilsky grade 2 improved to grade 1, and 53.8% of patients were stable. Five of 13 patients (38.4%) with initial Bilsky grade 3 improved to grade 1 to 2. Pain response at 3 and 6 months post-SBRT was complete in 45.4% and 55.7%, partial in 26.9% and 13.1%, stable in 24.1% and 27.9%, and worse in 3.7% and 3.3% of patients, respectively. At 3 and 6 months after SBRT, 17.8% and 25.0% of patients had improved ambulatory status and 79.7% and 72.4% had stable status. Conclusions: We report the largest series to date of patients with high-grade MESCC treated with SBRT. The excellent local control and functional outcomes suggest SBRT is a reasonable approach in inoperable patients or cases unable to be successfully surgically downgraded.

The Radiosurgery Society Case-Based Discussion of the Management of Head and Neck or Skull Base Paragangliomas with Stereotactic Radiosurgery and Radiotherapy.

Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) have been used for the treatment of head and neck or skull base paraganglioma for a considerable time, demonstrating promising local control rates and a favorable safety profile compared with surgical approaches. Nevertheless, the choice of treatment must be carefully tailored to each patient's preferences, tumor location, and size, as well as anticipated treatment-related morbidity. This case-based review serves as a practical and concise guide for the use of SRS and FSRT in the management of head and neck or skull base paragangliomas, providing information on the diagnosis, treatment, follow-up considerations, and potential pitfalls.

Radiotherapy concepts for spinal metastases-results from an online survey among radiation oncologists of the German Society for Radiation Oncology.

PURPOSE: Spinal metastases (SM) are a common radiotherapy (RT) indication. There is limited level I data to drive decision making regarding dose regimen (DR) and target volume definition (TVD). We aim to depict the patterns of care for RT of SM among German Society for Radiation Oncology (DEGRO) members. METHODS: An online survey on conventional RT and Stereotactic Body Radiation Therapy (SBRT) for SM, distributed via e­mail to all DEGRO members, was completed by 80 radiation oncologists between February 24 and April 29, 2022. Participation was voluntary and anonymous. RESULTS: A variety of DR was frequently used for conventional RT (primary: n = 15, adjuvant: n = 14). 30 Gy/10 fractions was reported most frequently. TVD in adjuvant RT was heterogenous, with a trend towards larger volumes. SBRT was offered in 65% (primary) and 21% (adjuvant) of participants' institutions. A variety of DR was reported (primary: n = 40, adjuvant: n = 27), most commonly 27 Gy/3 fractions and 30 Gy/5 fractions. 59% followed International Consensus Guidelines (ICG) for TVD. CONCLUSION: We provide a representative depiction of RT practice for SM among DEGRO members. DR and TVD are heterogeneous. SBRT is not comprehensively practiced, especially in the adjuvant setting. Further research is needed to provide a solid data basis for detailed recommendations.

Emergent radiotherapy for spinal cord compression/impingement-a narrative review.

BACKGROUND AND OBJECTIVE: Malignant epidural spinal cord compression (MESCC), often presenting with back pain and motor/sensory deficits, is associated with poor survival, particularly when there is loss of ambulation. The purpose of this review is to evaluate the literature and discuss appropriate workup and management of MESCC, specifically in the emergent setting. METHODS: A PubMed search was conducted on "spinal cord compression" and "radiation therapy." Articles were analyzed for the purpose of this narrative review. KEY CONTENT AND FINDINGS: If MESCC is suspected, neurologic examination and complete spine imaging are recommended. Emergent treatment is indicated if there is radiographic evidence of high-grade compression and/or clinically significant motor deficits. Treatment involves a combination of medical management, surgical decompression, radiation therapy (RT), and rehabilitation. For motor deficits, emergent initiation of high dose steroids is recommended. Circumferential surgical decompression ± stabilization followed by RT provides superior clinical outcomes than RT alone. For patients whom surgery is not reasonable, RT alone may provide significant treatment response which depends on radioresponsiveness of the pathology. Systemic therapy, if indicated, is typically reserved till after primary treatment of MESCC, but patients with chemoresponsive tumors may receive primary chemotherapy. The selected RT schedule should be personalized to each patient and commonly is 30 Gy in 10 fractions (fx), 20 Gy in 5 fx, or 8 Gy in 1 fx. MESCC recurrence may be treated with additional RT, if within the spinal cord tolerance, or surgery. Stereotactic body radiation therapy (SBRT) has been used for high grade MESCC in patients with relatively intact neurologic function at a few centers with a very robust infrastructure to support rapid initiation of treatment within a short period of time, but is generally not feasible for most clinical practices. SBRT may be advantageous for low grade MESCC, recurrence, or in the post-operative setting. Detection of MESCC prior to development of high-grade compression or deterioration of neurologic function may allow patients to benefit more from advanced therapies and improve prognosis. CONCLUSIONS: MESCC is a devastating condition; optimal treatment should be personalized to each patient and approached collaboratively by a multidisciplinary team.

Management and Molecular Characterization of Intraventricular Glioblastoma: A Single-Institution Case Series.

While the central nervous system (CNS) tumor classification has increasingly incorporated molecular parameters, there is a paucity of literature reporting molecular alterations found in intraventricular glioblastoma (IVGBM), which are rare. We present a case series of nine IVGBMs, including molecular alterations found in standardized next-generation sequencing (NGS). We queried the clinical charts, operative notes, pathology reports, and radiographic images of nine patients with histologically confirmed IVGBM treated at our institution (1995-2021). Routine NGS was performed on resected tumor tissue of two patients. In this retrospective case series of nine patients (22% female, median (range) age: 64.3 (36-85) years), the most common tumor locations were the atrium of the right lateral ventricle (33%) and the septum pellucidum (33%). Five patients had preoperative hydrocephalus, which was managed with intraoperative external ventricular drains in three patients and ventriculoperitoneal shunts in one patient. Hydrocephalus was managed with subtotal resection of a fourth ventricular IVGBM in one patient. The most common surgical approach was transcortical intraventricular (56%). Gross total resection was achieved in two patients, subtotal resection was achieved in six patients, and one patient received a biopsy only. Immunohistochemistry for IDH1 R132H mutant protein was performed in four cases and was negative in all four. Genetic alterations common in glioblastoma, IDH-wildtype, were seen in two cases with available NGS data, including EGFR gene amplification, TERT promoter mutation, PTEN mutation, trisomy of chromosome 7, and monosomy of chromosome 10. Following surgical resection, four patients received adjuvant chemoradiation. Median survival among our cohort was 4.7 months (IQR: 0.9-5.8 months). Management of IVGBM is particularly challenging due to their anatomical location, presentation with obstructive hydrocephalus, and fast growth, necessitating prompt intervention. Additional studies are needed to better understand the genetic landscape of IVGBM compared to parenchymal glioblastoma and may further elucidate the unique pathophysiology of these rare tumors.