Gamma knife radiosurgery for clival metastasis: case series and systematic review

PURPOSE

Clival metastatic cancer is rare and has limited literature to guide management. We describe management of clival metastasis with Gamma Knife radiosurgery (GKRS). We augment our findings with a systematic review of all forms of radiation therapy for clival metastasis.

METHODS

Records of 14 patients with clival metastasis who underwent GKRS at the University of Pittsburgh Medical Center from 2002 to 2023 were reviewed. Treatment parameters and clinical outcomes were assessed. A systematic review was conducted using evidence-based guidelines.

RESULTS

The average age was 61 years with male predominance (n = 10) and average follow-up of 12.4 months. The most common primary cancers were prostate (n = 3) and lung (n = 3). The average time from cancer diagnosis to clival metastasis was 34 months. The most common presenting symptoms were headache (n = 9) and diplopia (n = 7). Five patients presented with abducens nerve palsies, and two presented with oculomotor nerve palsies. The median tumor volume was 9.3 cc, and the median margin dose was 15 Gy. Eleven patients achieved tumor control after one procedure, and three with progression obtained tumor control after repeat GKRS. One patient recovered abducens nerve function. The median survival from cancer diagnosis and GKRS were 49.7 and 15.3 months, respectively. The cause of death was progression of systemic cancer in six patients, clival metastasis in one, and unknown in four. The systematic review included 31 studies with heterogeneous descriptions of treatment and outcomes.

CONCLUSION

Clival metastasis is rare and associated with poor prognosis. GKRS is a safe, effective treatment for clival metastasis.

The neurosurgery research & education foundation-young neurosurgeons committee webinar series: Providing education and inspiration during the COVID-19 pandemic

OBJECTIVE

During the COVID-19 pandemic, the American Association of Neurological Surgeons (AANS) Young Neurosurgeons Committee (YNC) and Neurosurgery Research & Education Foundation (NREF) launched the YNC-NREF Webinar Series to provide young and aspiring neurosurgeons with timely information, education, and inspiration in the absence of in-person programming.

DESIGN

Five 90-minute Zoom webinars were evaluated, each including 1-2 keynote speakers, a panel discussion, and an audience question-and-answer section. Topics included overviews of neurosurgery, the match, subspecialties, and inspirational career stories. Optional pre- and post-webinar surveys with 11-point Likert-type scores were distributed to attendees. We compared groups using chi-squared and Kruskal-Willis tests, and perceptions pre- and post-webinar using Mann-Whitney tests.

SETTING

The webinars were live using Zoom, and the recordings were published on NREF's YouTube channel.

PARTICIPANTS

The webinar series targeted young neurosurgeons. The first five episodes had a particular focus on medical students and undergraduates.

RESULTS

A total of 673 unique participants attended the webinar series; 257 (38%) and 78 (11%) attendees completed the pre- and post-webinar survey, respectively. Respondents had high baseline interest in neurosurgery and were motivated to learn about the match and training in the US, understand neurosurgeons' day-to-day lives, and ask questions. There were significant differences in perceptions between USMSs, IMSs, and undergraduate students. The webinar improved attendees' knowledge about neurosurgical specialties, the match, and US neurosurgery training.

CONCLUSIONS

The YNC and NREF effectively engaged a large, diverse audience through an online webinar series, building a foundation for future virtual programming by organized neurosurgery. ACGME competencies.

Intraoperative Imaging and Optical Visualization Techniques for Brain Tumor Resection: A Narrative Review

Advancements in intraoperative visualization and imaging techniques are increasingly central to the success and safety of brain tumor surgery, leading to transformative improvements in patient outcomes. This comprehensive review intricately describes the evolution of conventional and emerging technologies for intraoperative imaging, encompassing the surgical microscope, exoscope, Raman spectroscopy, confocal microscopy, fluorescence-guided surgery, intraoperative ultrasound, magnetic resonance imaging, and computed tomography. We detail how each of these imaging modalities contributes uniquely to the precision, safety, and efficacy of neurosurgical procedures. Despite their substantial benefits, these technologies share common challenges, including difficulties in image interpretation and steep learning curves. Looking forward, innovations in this field are poised to incorporate artificial intelligence, integrated multimodal imaging approaches, and augmented and virtual reality technologies. This rapidly evolving landscape represents fertile ground for future research and technological development, aiming to further elevate surgical precision, safety, and, most critically, patient outcomes in the management of brain tumors.

Can Advanced Radiotherapy Clinical Trials be Conducted in Resources Limited Countries?

PURPOSE/OBJECTIVE(S)

The Lancet Oncology Commission on Cancer in Sub-Saharan Africa (SSA) highlighted the region's increasing cancer incidence and mortality, and recommended a series of actions to address this growing crisis. One such approach recommended by the Commission to increase access to curative treatment is the use of hypofractionated radiotherapy (HFRT). Here we highlight the barriers and facilitators to launching HFRT in SSA, as identified through the HypoAfrica clinical trial.

MATERIALS/METHODS

HypoAfrica is a longitudinal multi-center clinical trial that was launched in late 2021 at three centers in Nigeria, Tanzania, and South Africa. The goal of HypoAfrica was to assess the feasibility of implementing HFRT for localized prostate cancer in SSA. To date, 155 of 182 subjects have been enrolled in this study. During the last year, a team of radiation oncology professionals from Africa, Europe, Australia, and USA met once every Saturday and reviewed the sites' data to identify the barriers to the implementation of HFRT and find solutions to overcome these challenges. With the intent to expand HFRT trials and practice to new SSA countries and radiotherapy centers, we also conducted an online survey to elucidate the readiness of radiotherapy centers across SSA to perform HFRT.

RESULTS

The major challenge identified by this team was securing high-quality data that will yield statistically significant results. Factors that contribute to quality data are: harmonization of machine and patient-specific quality assurance (QA) procedures across the centers, data quality harmonization, and challenges associated with machine maintenance. Immediate solutions implemented included introduction of low-cost QA tools for patient-specific QA measurements, ongoing training of the site's healthcare professionals, implementation of preventative maintenance for Linacs, and data centralization infrastructure. These actions have resulted in the production of a high-quality, standardized dataset. Planned longer-term solutions to HFRT challenges include implementation of ongoing training, telehealth for remote support and QA, and the creation of an Imaging and Radiation Oncology Core for Africa. The online survey indicated that 61% of respondents' institutions perform HFRT for palliative purposes, emphasizing the readiness of sites in SSA to utilize HFRT for curative purposes.

CONCLUSION

The study serves as a useful guide for increasing access to HFRT treatment in resource-limited settings and for conducting multicenter radiotherapy clinical trials.

Knowledge Based Planning for Lung SBRT: Model Transferability between Treatment Systems and Calculation Algorithms

PURPOSE/OBJECTIVE(S)

Knowledge based planning (KBP) is known to be effective and clinically feasible in achieving high quality treatment plans with less variability between planners and reduced planning time. A KBP model is highly dependent on characteristics of the training data. Our institution developed and validated a lung SBRT KBP model from plans treated with a C-arm linear accelerator (Linac). This study aims to evaluate the quality of lung SBRT plans with a KBP model when this model is used for an O-ring Linac with different MLC design, beam quality, and calculation algorithm.

MATERIALS/METHODS

Two academic hospitals in the same healthcare network were included in this study. One hospital trained a KBP model for five-fraction lung SBRT using 43 plans calculated using the Eclipse AcurosXB v15.6 algorithm for a C-arm Linac. The model was developed to prioritize dose gradient outside the PTV while satisfying institutional critical organ limits and validated using an additional set of 12 plans. A cohort of 10 patients (11 plans) previously treated with lung SBRT using the O-ring Linac at the second hospital was selected. These plans were calculated using the Eclipse AAA v15.6 algorithm with prescription doses of 30-50 Gy in five fractions. Each plan was re-optimized using the KBP model, without manual adjustment of the optimization objectives, using the same beam geometry as in the clinical plans. KBP plans were normalized to achieve the same PTV coverage as the clinical plans. Clinical and KBP plans were evaluated for ITV D98%, PTV conformity index (CI), R50 and maximum dose at 2 cm from the PTV (D2cm).

RESULTS

All clinical and KBP plans met critical organ dose constraints. The range of CI was 1-1.13 vs. 0.96-1.05 for clinical plans and KBP plans, respectively. R50 and D2cm were lower with KBP plans (p = 0.007 and p = 0.05, respectively). ITV D98% range was 105-120% vs. 117-122% of the PTV prescription dose for clinical plans and KBP plans, respectively, and higher with KBP plans (p<0.001). For plans where the PTV overlaps the chest wall (n = 7), the maximum chest wall doses (D0.03cc) from KBP plans were higher than the clinical plans (p = 0.16), with an absolute chest wall D0.03cc difference of 9 Gy (54 Gy vs 63 Gy). The KBP model includes an ITV SIB of 120% of the PTV prescription, whereas the clinical plans reduced the ITV SIB when the PTV overlapped the chest wall, highlighting a difference in clinical practice between the two hospitals in this study.

CONCLUSION

This study supports that a lung SBRT KBP model trained using plans for one Linac system and the AcurosXB algorithm can be used to generate clinically acceptable plans without manual planner intervention for a different Linac system and the AAA calculation algorithm, indicating the potential of a KBP model use for centralized planning process across different Linac systems and calculation algorithms.

Infant Rudimentary Meningocele with Tethering of the Cervical Cord: A Case Report

Rudimentary meningoceles of the spine with dural extension are very rare and warrant surgical excision to prevent infection and long-term neurological deficits in pediatric patients. We present the case of a 5-month-old infant with a tethered spinal cord secondary to a rudimentary meningocele. The patient presented shortly after birth with a midline cervical dimple that was evaluated for a suspected dermal sinus tract. Magnetic resonance imaging scan of the spine showed a sinus tract with intradural extension to C2-3 and external opening at the level of spinous process C5. En bloc surgical excision and spinal cord release were successfully performed. Histological analysis of the specimen confirmed the presence of two blunt sinus tracts and staining was consistent with a rudimentary meningocele. Intradural rudimentary meningoceles in infants can successfully be managed with surgical intervention. Surgery is indicated to prevent future motor complications from spinal cord tethering and neoplastic growth from the rudimentary meningocele.

Challenges and Opportunities for Increasing Adoption of Hypofractionated Radiotherapy in Low- and Middle-Income Countries

Purpose/Objective(s)

In the advent of the COVID-19 pandemic, professional societies including the American Society for Radiation Oncology and the National Comprehensive Cancer Network recommended increased adoption of evidence-based hypofractionated radiotherapy (HFRT), with benefits including significantly reducing the number of clinical visits for each patient to minimize potential exposure to infection, and reducing treatment costs and stress on limited workforce, particularly beneficial in Low-and-Middle-Income Countries (LMICs). Despite these benefits, HFRT adoption remains low, especially in LMICs. The purpose of this study is to investigate the challenges and opportunities for increased adoption of evidence-based HFRT in LMICs.

Materials/Methods

An IRB-approved survey was implemented in 18 sample radiotherapy centers in African LMIC to assess the challenges and utilization of HFRT. The experiences of three cancer centers were documented as part of an ongoing multi-center HFRT clinical trial designed to compare results with those reported for clinical trials involving North American and European Populations. Based on the findings assessed, challenges from the survey, and recorded experiences from the three centers, an online education and training program was developed in collaboration with the Global Health Catalyst, Radiation Knowledge and computer-based training tools for treatment planning, contouring, and online learning, with remote support provided by members from the international councils of ASTRO and AAPM.

Results

Only 8 of 18 surveyed clinics reported adopting HFRT as a common practice. Analysis of survey data demonstrated a significant need for training on contouring for radiation oncologists, and treatment planning and quality assurance. An education and training program was developed for implementation in the LMICs via a collaborative education model involving ASTRO and AAPM members who are faculty in USA institutions in collaboration with LMIC radiation oncology professionals.

Conclusion

The findings demonstrate a need for additional investment in infrastructure and training, as well as better ongoing education of oncology leaders on the benefits of increased adoption of evidence-based HFRT. The project also highlights opportunities and approaches for leveraging information and communication technology for collaborative high-impact global radiation oncology education, with the participation of members across both LMIC and USA institutions and professional societies. The HFRT training program provides a template for continuous education and training to increase the adoption of evidence-based approaches to HFRT that can significantly increase improved access to radiotherapy and reduce disparities in advancing globally the practice of radiation oncology. The impact of such a program and approach will be presented and discussed.

Circulating tumor DNA – A potential aid in the management of chordomas

Chordomas are a locally invasive, low-grade, CNS malignancy that are primarily found in the skull base, spine, and sacrum. They are thought to be derived from notochordal remnants and remain a significant clinical challenge due to their local invasiveness, resistance to chemoradiation, and difficulty in achieving a complete resection. Adjuvant therapy such as proton beam therapy is critical in preventing recurrence in patients who are at high risk, however this treatment is associated with increased risk of complication. Currently, intraoperative observation and imaging findings are used to determine recurrence and success of gross total resection. These methods can be unreliable due to limited operative view, bony and soft tissue involvement, and complex post-operative changes on MRI. Earlier detection of incomplete resection or recurrence will allow for earlier ability to intervene and potentially improve patient outcomes. Circulating-tumor DNA (ctDNA) is cell-free DNA that is released by tumor cells as they undergo cellular turn-over. Monitoring ctDNA has been shown to be more sensitive at predicting residual tumor than imaging in numerous solid malignancies. Furthermore, ctDNA could be detected earlier in peripheral blood as opposed to imaging changes, allowing for earlier intervention. In this review, we intend to give a brief overview of the current state of molecular diagnosis for skull base chordomas. We will then discuss current advances in the utilization of ctDNA for the management of CNS pathologies such as glioblastoma (GBM) and brain metastases. We will also discuss the role ctDNA has in the management of non-CNS pathologies such as osteosarcoma and Ewing sarcoma (EWS). Finally, we will discuss potential implications of ctDNA monitoring for chordoma management.

Predictors and Impact of Postoperative 30-Day Readmission in Glioblastoma

BACKGROUND

Postoperative 30-day readmissions have been shown to negatively affect survival and other important outcomes in patients with glioblastoma (GBM).

OBJECTIVE

To further investigate patient readmission risk factors of primary and recurrent patients with GBM.

METHODS

The authors retrospectively reviewed records of 418 adult patients undergoing 575 craniotomies for histologically confirmed GBM at an academic medical center. Patient demographics, comorbidities, and clinical characteristics were collected and compared by patient readmission status using chi-square and Mann-Whitney U testing. Multivariable logistic regression was performed to identify risk factors that predicted 30-day readmissions.

RESULTS

The cohort included 69 (12%) 30-day readmissions after 575 operations. Readmitted patients experienced significantly lower median overall survival (11.3 vs 16.4 months, P = .014), had a lower mean Karnofsky Performance Scale score (66.9 vs 74.2, P = .005), and had a longer initial length of stay (6.1 vs 5.3 days, P = .007) relative to their nonreadmitted counterparts. Readmitted patients experienced more postoperative deep vein thromboses or pulmonary embolisms (12% vs 4%, P = .006), new motor deficits (29% vs 14%, P = .002), and nonhome discharges (39% vs 22%, P = .005) relative to their nonreadmitted counterparts. Multivariable analysis demonstrated increased odds of 30-day readmission with each 10-point decrease in Karnofsky Performance Scale score (odds ratio [OR] 1.32, P = .002), each single-point increase in 5-factor modified frailty index (OR 1.51, P = .016), and initial presentation with cognitive deficits (OR 2.11, P = .013).

CONCLUSION

Preoperatively available clinical characteristics strongly predicted 30-day readmissions in patients undergoing surgery for GBM. Opportunities may exist to optimize preoperative and postoperative management of at-risk patients with GBM, with downstream improvements in clinical outcomes.

248 Urethral Self-Insertion of a USB Cable as Sexual Experimentation: A Case Report

Introduction

The insertion of a foreign body in the urethra is an uncommon urological emergency. A wide variety of inserted objects have been described, presenting either asymptomatically or with lower abdominal discomfort and lower urinary tract symptoms. Sexual experimentation and gratification as well as mental disorders are considered the main underlying causes. The aim of this report is to present the case of a USB wire self-insertion and its challenging urological management.

Case Presentation

A 15-year-old male patient presented to his local Accident and Emergency department with gross haematuria following self-insertion of the knotted cable of a USB wire into his urethra in the context of sexual experimentation. Endoscopic approach via rigid cystoscopy and optical urethrotomy was not effective. A suprapubic catheter was inserted, and the patient was urgently transferred to our hospital for tertiary management.

Following radiological assessment to confirm the position of the wire, a longitudinal peno-scrotal incision over the palpable foreign body was made. Urethrotomy revealed the knotted cable in the proximal aspect of the penile urethra, which was cut and removed. Urethra was subsequently closed over a urethral catheter. Postoperative recovery was uneventful, and patient was discharged home with oral antibiotics. Urethral catheter was removed following normal fluoroscopic assessment of the urethra two weeks later.

Conclusions

The management of a foreign urethral body can be challenging and usually requires tertiary expertise to achieve optimal outcomes. Poor initial management could potentially lead to devastating long-term complications such as urethral strictures and fistulas.

Synergy between glutamate modulation and anti-programmed cell death protein 1 immunotherapy for glioblastoma

OBJECTIVE

Immune checkpoint inhibitors such as anti-programmed cell death protein 1 (anti-PD-1) have shown promise for the treatment of cancers such as melanoma, but results for glioblastoma (GBM) have been disappointing thus far. It has been suggested that GBM has multiple mechanisms of immunosuppression, indicating a need for combinatorial treatment strategies. It is well understood that GBM increases glutamate in the tumor microenvironment (TME); however, the significance of this is not well understood. The authors posit that glutamate upregulation in the GBM TME is immunosuppressive. The authors utilized a novel glutamate modulator, BHV-4157, to determine synergy between glutamate modulation and the well-established anti-PD-1 immunotherapy for GBM.

METHODS

C57BL/6J mice were intracranially implanted with luciferase-tagged GL261 glioma cells. Mice were randomly assigned to the control, anti-PD-1, BHV-4157, or combination anti-PD-1 plus BHV-4157 treatment arms, and median overall survival was assessed. In vivo microdialysis was performed at the tumor site with administration of BHV-4157. Intratumoral immune cell populations were characterized with immunofluorescence and flow cytometry.

RESULTS

The BHV-4157 treatment arm demonstrated improved survival compared with the control arm (p < 0.0001). Microdialysis demonstrated that glutamate concentration in TME significantly decreased after BHV-4157 administration. Immunofluorescence and flow cytometry demonstrated increased CD4+ T cells and decreased Foxp3+ T cells in mice that received BHV-4157 treatment. No survival benefit was observed when CD4+ or CD8+ T cells were depleted in mice prior to BHV-4157 administration (p < 0.05).

CONCLUSIONS

In this study, the authors showed synergy between anti-PD-1 immunotherapy and glutamate modulation. The authors provide a possible mechanism for this synergistic benefit by showing that BHV-4157 relies on CD4+ and CD8+ T cells. This study sheds light on the role of excess glutamate in GBM and provides a basis for further exploring combinatorial approaches for the treatment of this disease.

Disulfiram and copper combination therapy targets NPL4, cancer stem cells and extends survival in a medulloblastoma model

Background

Medulloblastoma (MB) is the most common brain malignancy in children, and is still responsible for significant mortality and morbidity. The aim of this study was to assess the safety and efficacy of Disulfiram (DSF), an FDA-approved inhibitor of Aldehyde-Dehydrogenase (ALDH), and Copper (Cu⁺⁺) in human SSH-driven and Group 3 MB. The molecular mechanisms, effect on cancer-stem-cells (CSC) and DNA damage were investigated in xenograft models.

Methods

The cytotoxic and anti-CSC effects of DSF/Cu⁺⁺ were evaluated with clonogenic assays, flow-cytometry, immunofluorescence, western-blotting. ONS76, UW228 (SHH-driven with Tp53m), D425med, D283 and D341 (Group 3) cell-lines were used. In vivo survival and nuclear protein localization protein-4 (NPL4), Ki67, Cleaved-Caspase-3, GFAP and NeuN expression were assessed in two Group 3 MB xenografts with immunohistochemistry and western-blotting.

Results

Significant in vitro cytotoxicity was demonstrated at nanomolar concentrations. DSF/Cu⁺⁺ induced cell-death through NPL4 accumulation in cell-nucleus and buildup of poly-ubiquitylated proteins. Flow-cytometry demonstrated a significant decrease in ALDH⁺, Nestin⁺ and CD133⁺ following treatment, anti-CSC effect was confirmed in vitro and in vivo. DSF/Cu⁺⁺ prolonged survival, and increased nuclear NPL4 expression in vivo.

Conclusions

Our data suggest that this combination may serve as a novel treatment, as monotherapy or in combination with existing therapies, for aggressive subtypes of pediatric MB.

Targeting of cyclin-dependent kinases in atypical teratoid rhabdoid tumors with multikinase inhibitor TG02

OBJECTIVE

Atypical teratoid rhabdoid tumors (ATRTs) are aggressive pediatric brain tumors with no current standard of care and an estimated median patient survival of 12 to 18 months. Previous genetic analyses have implicated cyclin D1 and enhancer of zeste homolog 2 (EZH2), a histone methyltransferase that is implicated in many cancers, as key drivers of tumorigenicity in ATRTs. Since the effects of EZH2 and cyclin D1 are facilitated by a host of cyclin-dependent kinases (CDKs), the authors sought to investigate the potential therapeutic effects of targeting CDKs in ATRTs with the multi-CDK inhibitor, TG02.

METHODS

Human ATRT cell lines BT12, BT37, CHLA05, and CHLA06 were selected for investigation. The effects of TG02 on cell viability, proliferation, clonogenicity, and apoptosis were assessed via Cell Counting Kit-8 assays, cell counting, clonogenic assays, and flow cytometry, respectively. Similar methods were used to determine the effects of TG02 combined with radiation therapy (RT) or cisplatin. Synergism indices for TG02-cisplatin combination therapy were calculated using CompuSyn software.

RESULTS

TG02 was observed to significantly impair ATRT cell growth in vitro by limiting cell proliferation and clonogenicity, and by inducing apoptosis. TG02 inhibited ATRT cell proliferation and decreased cell viability in a dose-dependent manner with nanomolar half maximal effective concentration (EC50) values (BT12, 207.0 nM; BT37, 127.8 nM; CHLA05, 29.7 nM; CHLA06, 18.7 nM). TG02 (150 nM) dramatically increased the proportion of apoptotic ATRT cells 72 hours posttreatment (TG02 8.50% vs control 1.52% apoptotic cells in BT12, p < 0.0001; TG02 70.07% vs control 15.36%, p < 0.0001). Combination therapy studies revealed that TG02 acted as a potent radiosensitizer in ATRT cells (BT12 surviving fraction, RT 51.2% vs RT + TG02 21.7%). Finally, CompuSyn analysis demonstrated that TG02 acted synergistically with cisplatin against ATRT cells at virtually all therapeutic doses. These findings were consistent in cell lines that cover all three molecular subgroups of ATRTs.

CONCLUSIONS

The results of this investigation have established that TG02 is an effective therapeutic against ATRTs in vitro. Given the lack of standard therapy for ATRTs, these findings help fill an unmet need and support further study of TG02 as a potential therapeutic option for patients with this deadly disease.

Adapting the 5-factor modified frailty index for prediction of postprocedural outcome in patients with unruptured aneurysms

OBJECTIVE

The 5-factor modified frailty index (mFI-5) is a practical tool that can be used to estimate frailty by measuring five accessible factors: functional status, history of diabetes, chronic obstructive pulmonary disease, congestive heart failure, and hypertension. The authors aimed to validate the utility of mFI-5 for predicting endovascular and microsurgical treatment outcomes in patients with unruptured aneurysms.

METHODS

A prospectively maintained database of consecutive patients with unruptured aneurysm who were treated with clip placement or endovascular therapy was used. Because patient age is an important predictor of treatment outcomes in patients with unruptured aneurysm, mFI-5 was supplemented with age to create the age-supplemented mFI-5 (AmFI-5). Associations of scores on these indices with major complications (symptomatic ischemic or hemorrhagic stroke, pulmonary embolism, pneumonia, or surgical site infection requiring reoperation) were evaluated. Validation was carried out with the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database (2006-2017).

RESULTS

The institutional database included 275 patients (88 underwent clip placement, and 187 underwent endovascular treatment). Multivariable analysis of the surgical cohort showed that major complication was significantly associated with mFI-5 (OR 2.0, p = 0.046) and AmFI-5 (OR 1.9, p = 0.028) scores. Significant predictive accuracy for major complications was provided by mFI-5 (c-statistic = 0.709, p = 0.011) and AmFI-5 (c-statistic = 0.720, p = 0.008). The American Society of Anesthesiologists Physical Status Classification System (ASA) provided poor discrimination (area under the curve = 0.541, p = 0.618) that was significantly less than that of mFI-5 (p = 0.023) and AmFI-5 (p = 0.014). Optimal relative fit was achieved with AmFI-5, which had the lowest Akaike information criterion value. Similar results were obtained after equivalent analysis of the endovascular cohort, with additional significant associations between index scores and length of stay (β = 0.6 and p = 0.009 for mFI-5; β = 0.5 and p = 0.003 for AmFI-5). In 1047 patients who underwent clip placement and were included in the NSQIP database, mFI-5 (p = 0.001) and AmFI-5 (p < 0.001) scores were significantly associated with severe postoperative adverse events and provided greater discrimination (c-statistic = 0.600 and p < 0.001 for mFI-5; c-statistic = 0.610 and p < 0.001 for AmFI-5) than ASA score (c-statistic = 0.580 and p = 0.003).

CONCLUSIONS

mFI-5 and AmFI-5 represent potential predictors of procedure-related complications in unruptured aneurysm patients. After further validation, integration of these tools into clinical workflows may optimize patients for intervention.

Alpha-1 adrenergic receptor antagonists to prevent hyperinflammation and death from lower respiratory tract infection

In severe viral pneumonia, including Coronavirus disease 2019 (COVID-19), the viral replication phase is often followed by hyperinflammation, which can lead to acute respiratory distress syndrome, multi-organ failure, and death. We previously demonstrated that alpha-1 adrenergic receptor ($\alpha_1$-AR) antagonists can prevent hyperinflammation and death in mice. Here, we conducted retrospective analyses in two cohorts of patients with acute respiratory distress (ARD, n=18,547) and three cohorts with pneumonia (n=400,907). Federated across two ARD cohorts, we find that patients exposed to $\alpha_1$-AR antagonists, as compared to unexposed patients, had a 34% relative risk reduction for mechanical ventilation and death (OR=0.70, p=0.021). We replicated these methods on three pneumonia cohorts, all with similar effects on both outcomes. All results were robust to sensitivity analyses. These results highlight the urgent need for prospective trials testing whether prophylactic use of $\alpha_1$-AR antagonists ameliorates lower respiratory tract infection-associated hyperinflammation and death, as observed in COVID-19.

Patient-Specific Factors Drive Intensive Care Unit and Total Hospital Length of Stay in Operative Patients with Brain Tumor

BACKGROUND

Hospital length of stay (LOS) is an important cost driver in neurosurgery. Broader surgical literature has shown that patient-related factors, including comorbidities, and procedure-related factors, such surgeon experience, may be associated with LOS. Because value optimization strategies may be targeted toward either domain, this study investigated the contributions of patient-related and procedure-related factors in predicting prolonged intensive care unit LOS (iLOS) and total hospital LOS (tLOS).

METHODS

Data for adult patients undergoing brain tumor surgery (2017-2019) were collected. Bivariate analyses for iLOS and tLOS were performed using the Mann-Whitney U test and Fisher exact test. Variables associated with either outcome with P < 0.10 were included in patient-only, procedure-only, and patient+procedure factor multivariate linear regression models. Model discrimination was quantified using C-statistics.

RESULTS

Our 654 patients had a mean age of 57.54 years (standard deviation, ± 14.34 years). For iLOS, the patient-only model significantly outperformed the procedure-only model (P < 0.0001) and performed similarly to the patient+procedure model (P = 0.50). Other than tumor diagnosis, 5-Factor Modified Frailty Index score was the only factor associated with iLOS (P < 0.001) and tLOS (P < 0.001) on multivariate analysis. When predicting prolonged tLOS, the patient-only model significantly outperformed the procedure-only model (P < 0.0001), and performed similarly to patient+procedure models (P = 0.49).

CONCLUSIONS

Patient-specific factors are the main drivers of prolonged iLOS and tLOS among patients with brain tumor. Frailty was significantly associated with both iLOS and tLOS on multivariate analysis. Efforts to improve care value should focus on strategies to optimize patient status, such as prehabilitation and enhanced recovery after surgery.

A novel radiographic marker of sarcopenia with prognostic value in glioblastoma

OBJECTIVE

Sarcopenia is an important prognostic consideration in surgical oncology that has received relatively little attention in brain tumor patients. Temporal muscle thickness (TMT) has recently been proposed as a novel radiographic marker of sarcopenia that can be efficiently obtained within existing workflows. We investigated the prognostic value of TMT in primary and progressive glioblastoma.

METHODS

TMT measurements were performed on magnetic resonance images of 384 patients undergoing 541 surgeries for glioblastoma. Relationships between TMT and clinical characteristics were examined on bivariate analysis. Optimal TMT cutpoints were established using maximally selected rank statistics. Predictive value of TMT upon postoperative survival (PS) was assessed using Cox proportional hazards regression adjusted for age, sex, Karnofsky performance status (KPS), Stupp protocol completion, extent of resection, and tumor molecular markers.

RESULTS

Average TMT for the primary and progressive glioblastoma cohorts was 9.55 mm and 9.40 mm, respectively. TMT was associated with age (r = -0.14, p = 0.0008), BMI (r = 0.29, p < 0.0001), albumin (r = 0.11, p = 0.0239), and KPS (r = 0.11, p = 0.0101). Optimal TMT cutpoints for the primary and progressive cohorts were ≤ 7.15 mm and ≤ 7.10 mm, respectively. High TMT was associated with increased Stupp protocol completion (p = 0.001). On Cox proportional hazards regression, high TMT predicted increased PS in progressive [HR 0.47 (95% confidence interval (CI)) 0.25-0.90), p = 0.023] but not primary [HR 0.99 (95% CI 0.64-1.51), p = 0.949] glioblastoma.

CONCLUSIONS

TMT correlates with important prognostic variables in glioblastoma and predicts PS in patients with progressive, but not primary, disease. TMT may represent a pragmatic neurosurgical biomarker in glioblastoma that could inform treatment planning and perioperative optimization.

Captopril inhibits Matrix Metalloproteinase-2 and extends survival as a temozolomide adjuvant in an intracranial gliosarcoma model

BACKGROUND

Captopril is a well-characterized, FDA-approved drug that has demonstrated promise as a repurposed oncology therapeutic. Captopril's known anti-cancer effects include inhibition of Matrix Metalloproteinase-2 (MMP-2), an endopeptidase which selectively breaks down the extracellular matrix to promote cell migration. MMP-2 is a known therapeutic target in gliomas, tumors with significant clinical need. Using an aggressive gliosarcoma model, we assessed captopril's effects on MMP-2 expression in vitro and in vivo as well as its efficacy as an adjuvant in combination therapy regimens in vivo.

METHODS

Following captopril treatment, MMP-2 protein expression and migratory capabilities of 9 L gliosarcoma cells were assessed in vitro via western blots and scratch wound assays, respectively. Rats were intracranially implanted with 9 L gliosarcoma tumors, and survival was assessed in the following groups: control; captopril (30 mg/kg/day); temozolomide (TMZ) (50 mg/kg/day), and captopril+TMZ. In vivo experiments were accompanied by immunohistochemistry for MMP-2 from brain tissue.

RESULTS

In vitro, captopril decreased MMP-2 protein expression and reduced migratory capacity in 9 L gliosarcoma cells. In a gliosarcoma animal model, captopril decreased MMP-2 protein expression and extended survival as a TMZ adjuvant relative to untreated controls, captopril monotherapy, and TMZ monotherapy groups (27.5 versus 14 (p < 0.001), 16 (p < 0.001), and 23 (p = 0.018) days, respectively).

CONCLUSIONS

Captopril decreases gliosarcoma cell migration, which may be mediated by reduction in MMP-2 protein expression. Captopril provided a survival advantage as a TMZ adjuvant in a rat intracranial gliosarcoma model. Captopril may represent a promising potential adjuvant to TMZ therapy in gliosarcoma as a modulator of the MMP-2 pathway.

"Zooming in" on Glioblastoma: Understanding Tumor Heterogeneity and its Clinical Implications in the Era of Single-Cell Ribonucleic Acid Sequencing

Glioblastoma (GBM) is the most common primary brain malignancy in adults and one of the most aggressive of all human cancers. It is highly recurrent and treatment-resistant, in large part due to its infiltrative nature and inter- and intratumoral heterogeneity. This heterogeneity entails varying genomic landscapes and cell types within and between tumors and the tumor microenvironment (TME). In GBM, heterogeneity is a driver of treatment resistance, recurrence, and poor prognosis, representing a substantial impediment to personalized medicine. Over the last decade, sequencing technologies have facilitated deeper understanding of GBM heterogeneity by "zooming in" progressively further on tumor genomics and transcriptomics. Initial efforts employed bulk ribonucleic acid (RNA) sequencing, which examines composite gene expression of whole tumor specimens. While groundbreaking at the time, this bulk RNAseq masks the crucial contributions of distinct tumor subpopulations to overall gene expression. This work progressed to the use of bulk RNA sequencing in anatomically and spatially distinct tumor subsections, which demonstrated previously underappreciated genomic complexity of GBM. A revolutionary next step forward has been the advent of single-cell RNA sequencing (scRNAseq), which examines gene expression at the single-cell level. scRNAseq has enabled us to understand GBM heterogeneity in unprecedented detail. We review seminal studies in our progression of understanding GBM heterogeneity, with a focus on scRNAseq and the insights that it has provided into understanding the GBM tumor mass, peritumoral space, and TME. We highlight preclinical and clinical implications of this work and consider its potential to impact neuro-oncology and to improve patient outcomes via personalized medicine.

Web-Based Calculator Predicts Surgical-Site Infection After Thoracolumbar Spine Surgery

BACKGROUND

Surgical-site infection (SSI) after spine surgery leads to increased length of stay, reoperation, and worse patient quality of life. We sought to develop a web-based calculator that computes an individual's risk of a wound infection following thoracolumbar spine surgery.

METHODS

We performed a retrospective review of consecutive patients undergoing elective degenerative thoracolumbar spine surgery at a tertiary-care institution between January 2016 and December 2018. Patients who developed SSI requiring reoperation were identified. Regression analysis was performed and model performance was assessed using receiver operating curve analysis to derive an area under the curve. Bootstrapping was performed to check for overfitting, and a Hosmer-Lemeshow test was employed to evaluate goodness-of-fit and model calibration.

RESULTS

In total, 1259 patients were identified; 73% were index operations. The overall infection rate was 2.7%, and significant predictors of SSI included female sex (odds ratio [OR] 3.0), greater body mass index (OR 1.1), active smoking (OR 2.8), worse American Society of Anesthesiologists physical status (OR 2.1), and greater surgical invasiveness (OR 1.1). The prediction model had an optimism-corrected area under the curve of 0.81. A web-based calculator was created: https://jhuspine2.shinyapps.io/Wound_Infection_Calculator/.

CONCLUSIONS

In this pilot study, we developed a model and simple web-based calculator to predict a patient's individualized risk of SSI after thoracolumbar spine surgery. This tool has a predictive accuracy of 83%. Through further multi-institutional validation studies, this tool has the potential to alert both patients and providers of an individual's SSI risk to improve informed consent, mitigate risk factors, and ultimately drive down rates of SSIs.

Predicting Postoperative Outcomes in Brain Tumor Patients With a 5-Factor Modified Frailty Index

BACKGROUND

Frailty indices may represent useful decision support tools to optimize modifiable drivers of quality and cost in neurosurgical care. However, classic indices are cumbersome to calculate and frequently require unavailable data. Recently, a more lean 5-factor modified frailty index (mFI-5) was introduced, but it has not yet been rigorously applied to brain tumor patients.

OBJECTIVE

To investigate the predictive value of the mFI-5 on length of stay (LOS), complications, and charges in surgical brain tumor patients.

METHODS

We retrospectively reviewed data for brain tumor patients who underwent primary surgery from 2017 to 2018. Bivariate (ANOVA) and multivariate (logistic and linear regression) analyses assessed the predictive power of the mFI-5 on postoperative outcomes.

RESULTS

Our cohort included 1692 patients with a mean age of 55.5 yr and mFI-5 of 0.80. Mean intensive care unit (ICU) and total LOS were 1.69 and 5.24 d, respectively. Mean pulmonary embolism (PE)/deep vein thrombosis (DVT), physiological/metabolic derangement, respiratory failure, and sepsis rates were 7.2%, 1.1%, 1.6%, and 1.7%, respectively. Mean total charges were $42 331. On multivariate analysis, each additional point on the mFI-5 was associated with a 0.32- and 1.38-d increase in ICU and total LOS, respectively; increased odds of PE/DVT (odds ratio (OR): 1.50), physiological/metabolic derangement (OR: 3.66), respiratory failure (OR: 1.55), and sepsis (OR: 2.12); and an increase in total charges of $5846.

CONCLUSION

The mFI-5 is a pragmatic and actionable tool which predicts LOS, complications, and charges in brain tumor patients. It may guide future efforts to risk-stratify patients with subsequent impact on postoperative outcomes.

Preclinical efficacy of ribavirin in SHH and group 3 medulloblastoma

OBJECTIVE

Medulloblastoma, the most common pediatric brain malignancy, has Sonic Hedgehog (SHH) and group 3 (Myc driven) subtypes that are associated with the activity of eukaryotic initiation factor 4E (eIF4E), a critical mediator of translation, and enhancer of zeste homolog 2 (EZH2), a histone methyltransferase and master regulator of transcription. Recent drug repurposing efforts in multiple solid and hematologic malignancies have demonstrated that eIF4E and EZH2 are both pharmacologically inhibited by the FDA-approved antiviral drug ribavirin. Given the molecular overlap between medulloblastoma biology and known ribavirin activity, the authors investigated the preclinical efficacy of repurposing ribavirin as a targeted therapeutic in cell and animal models of medulloblastoma.

METHODS

Multiple in vitro assays were performed using human ONS-76 (a primitive SHH model) and D425 (an aggressive group 3 model) cells. The impacts of ribavirin on cellular growth, death, migration, and invasion were quantified using proliferation and Cell Counting Kit-8 (CCK-8) assays, flow cytometry with annexin V (AnnV) staining, scratch wound assays, and Matrigel invasion chambers, respectively. Survival following daily ribavirin treatment (100 mg/kg) was assessed in vivo in immunodeficient mice intracranially implanted with D425 cells.

RESULTS

Compared to controls, ribavirin treatment led to a significant reduction in medulloblastoma cell growth (ONS-76 proliferation assay, p = 0.0001; D425 CCK-8 assay, p < 0.0001) and a significant increase in cell death (flow cytometry for AnnV, ONS-76, p = 0.0010; D425, p = 0.0284). In ONS-76 cells, compared to controls, ribavirin significantly decreased cell migration and invasion (Matrigel invasion chamber assay, p = 0.0012). In vivo, ribavirin significantly extended survival in an aggressive group 3 medulloblastoma mouse model compared to vehicle-treated controls (p = 0.0004).

CONCLUSIONS

The authors demonstrate that ribavirin, a clinically used drug known to inhibit eIF4E and EZH2, has significant antitumor effects in multiple preclinical models of medulloblastoma, including an aggressive group 3 animal model. Ribavirin may represent a promising targeted therapeutic in medulloblastoma.

Alpha-1 adrenergic receptor antagonists to prevent hyperinflammation and death from lower respiratory tract infection

In severe viral pneumonia, including Coronavirus disease 2019 (COVID-19), the viral replication phase is often followed by hyperinflammation, which can lead to acute respiratory distress syndrome, multi-organ failure, and death. We previously demonstrated that alpha-1 adrenergic receptor (⍺₁-AR) antagonists can prevent hyperinflammation and death in mice. Here, we conducted retrospective analyses in two cohorts of patients with acute respiratory distress (ARD, n = 18,547) and three cohorts with pneumonia (n = 400,907). Federated across two ARD cohorts, we find that patients exposed to ⍺₁-AR antagonists, as compared to unexposed patients, had a 34% relative risk reduction for mechanical ventilation and death (OR = 0.70, p = 0.021). We replicated these methods on three pneumonia cohorts, all with similar effects on both outcomes. All results were robust to sensitivity analyses. These results highlight the urgent need for prospective trials testing whether prophylactic use of ⍺₁-AR antagonists ameliorates lower respiratory tract infection-associated hyperinflammation and death, as observed in COVID-19.

The 5-factor modified frailty index predicts health burden following surgery for pituitary adenomas

PURPOSE

Frailty is known to influence cost-related surgical outcomes in neurosurgery, but quantifying frailty is often challenging. Therefore, we investigated the predictive value of the 5-factor modified frailty index (mFI-5) on total hospital charges, LOS, and 90-day readmission for patients undergoing pituitary surgery.

METHODS

The medical records of all patients undergoing endoscopic endonasal resection of pituitary adenomas at an academic medical center between January 2017 and December 2018 were retrospectively reviewed. Bivariate statistical analyses were conducted using Fisher's exact test, chi-square test, and independent samples t-test. Linear and logistic regression models were used for multivariate analysis.

RESULTS

Our cohort (n = 234) had a mean age of 53.8 years (standard deviation 14.6 years). Sex distributions were equal, and most patients were Caucasian (59%). On multivariate linear regression, with each one-point increase in mFI-5, total LOS increased by 0.64 days in the overall cohort (p < 0.001), 1.08 days in the Cushing disease cohort (p = 0.045), and 0.59 days in non-functioning tumors cohort (p = 0.004). Total charges increased by $3954 in the whole cohort (p < 0.001), $10,652 in the Cushing disease cohort (p = 0.033), and $2902 in the non-functioning tumors cohort (p = 0.007) with each one-point increase in mFI-5. Greater mFI-5 scores were associated with greater odds of 90-day readmission in both overall and Cushing disease cohorts, but these associations did not reach statistical significance.

CONCLUSION

A patient's mFI-5 score is significantly associated with increased length of stay and hospital charges for patients undergoing pituitary surgery. The mFI-5 may hold peri-operative value in patient counseling for pituitary adenoma surgery.

A novel predictive model of intraoperative blood loss in patients undergoing elective lumbar surgery for degenerative pathologies

BACKGROUND CONTEXT

Intraoperative blood loss (IOBL) is unavoidable during surgery; however, high IOBL is associated with increased morbidity and increased risk for requiring allogenic blood transfusion, itself associated with poorer outcomes.

PURPOSE

Here we sought to develop and validate a predictive calculator for IOBL that could be used by surgeons to estimate likely blood loss.

STUDY DESIGN/SETTING

Retrospective cohort.

PATIENT SAMPLE

Series of consecutive patients who underwent elective lumbar spine surgery for degenerative pathologies over a 27-month period at a single tertiary care center.

OUTCOME MEASURES

Primary outcome was IOBL. Secondary outcome was the occurrence of "major intraoperative bleeding," defined as IOBL exceeding 1 L.

METHODS

Charts of included patients were reviewed for medical comorbidities, preoperative laboratory data, surgical plan, and anesthesia records. Univariate linear regressions were performed to find significant predictors of IOBL, which were then subjected to a multivariate analysis to identify the final model. Model training was performed using 70% of the included cohort and external validation was performed using 30% of the cohort. Results of the model were deployed as a freely available online calculator.

RESULTS

We identified 1,281 patients who met inclusion/exclusion criteria. Mean age was 60±15 years, mean Charlson Comorbidity score was 1.1±1.6, and 51.8% were male. There were no significant differences between the training and validation cohorts with regard to any of the demographic variables or intraoperative variables; tranexamic acid use and surgical invasiveness were also similar in both cohorts. Multivariate analysis identified body mass index (βₙ=7.14; 95% confidence interval [3.15, 11.13]; p<.001), surgical invasiveness (βₙ=29.18; [24.62, 33.74]; p<.001), tranexamic acid use (βₙ=-0.093; [-0.171, -0.014]; p=.02), and surgical duration (βₙ=2.13; [1.75, 2.51]; p<.001) as significant predictors of IOBL. The model had an overall fit of r=0.693 in the validation cohort. Construction of a receiver-operating curve for predicting major IOBL showed a C-statistic of 0.895 within the validation cohort.

CONCLUSION

Here we identify and validate a model for predicting IOBL in patients undergoing lumbar spine surgery. The model was a moderately strong predictor of absolute IOBL and was demonstrated to predict the occurrence of major IOBL with a high degree of accuracy. We propose it may have future utility when counseling patients about surgical morbidity and the probability of requiring transfusion.

The Prognostic Impact of Nutritional Status on Postoperative Outcomes in Glioblastoma

OBJECTIVE

The clinical impact and optimal method of assessing nutritional status (NS) have not been rigorously examined in glioblastoma. We investigated the relationship between NS and postoperative survival (PS) in glioblastoma using 4 nutritional indices and identified which index best modeled PS.

METHODS

NS was retrospectively assessed for patients with glioblastoma undergoing surgery at our institution from 2007 to 2019 using the albumin level, albumin/globulin ratio (AGR), nutritional risk index (NRI), and prognostic nutritional index (PNI). Optimal cut points for each index were identified using maximally selected rank statistics and previously established criteria. The predictive value of each index on PS was determined using Cox proportional hazards models adjusted for prognostic variables. The best-performing model was identified using the Akaike Information Criterion.

RESULTS

Our analysis included 242 patients (64% male) with a mean age of 57.6 years, Karnofsky Performance Status of 77.6, 5-factor modified frailty index of 0.59, albumin level of 4.2 g/dL, AGR of 1.9, NRI of 105.6, and PNI of 47.4. Median PS after index and repeat surgery was 12.7 and 7.8 months, respectively. On multivariable analysis, low albumin level (hazard ratio [HR], 2.09; 95% confidence interval [CI], 1.52-2.89; P < 0.001), mild NRI (HR, 1.61; 95% CI, 1.04-2.49; P = 0.032), moderate/severe NRI (HR, 2.51; 95% CI, 1.64-3.85; P < 0.001), and low PNI (HR, 2.51; 95% CI, 1.78-3.53; P < 0.001), but not low AGR (HR, 1.17; 95% CI, 0.89-1.54; P = 0.270), predicted decreased PS. PNI had the lowest Akaike Information Criterion.

CONCLUSIONS

NS predicts PS in glioblastoma. PNI may provide the best model for assessing NS. NS is an important modifiable aspect of brain tumor management that warrants increased attention.

Predictive Model and Online Calculator for Discharge Disposition in Brain Tumor Patients

BACKGROUND

In the era of value-based payment models, it is imperative for neurosurgeons to eliminate inefficiencies and provide high-quality care. Discharge disposition is a relevant consideration with clinical and economic ramifications in brain tumor patients. We developed a predictive model and online calculator for postoperative non-home discharge disposition in brain tumor patients that can be incorporated into preoperative workflows.

METHODS

We reviewed all brain tumor patients at our institution from 2017 to 2019. A predictive model of discharge disposition containing preoperatively available variables was developed using stepwise multivariable logistic regression. Model performance was assessed using receiver operating characteristic curves and calibration curves. Internal validation was performed using bootstrapping with 2000 samples.

RESULTS

Our cohort included 2335 patients who underwent 2586 surgeries with a 16% non-home discharge rate. Significant predictors of non-home discharge were age >60 years (odds ratio [OR], 2.02), African American (OR, 1.73) or Asian (OR, 2.05) race, unmarried status (OR, 1.48), Medicaid insurance (OR, 1.90), admission from another health care facility (OR, 2.30), higher 5-factor modified frailty index (OR, 1.61 for 5-factor modified frailty index ≥2), and lower Karnofsky Performance Status (increasing OR with each 10-point decrease in Karnofsky Performance Status). The model was well calibrated and had excellent discrimination (optimism-corrected C-statistic, 0.82). An open-access calculator was deployed (https://neurooncsurgery.shinyapps.io/discharge_calc/).

CONCLUSIONS

A strongly performing predictive model and online calculator for non-home discharge disposition in brain tumor patients was developed. With further validation, this tool may facilitate more efficient discharge planning, with consequent improvements in quality and value of care for brain tumor patients.

EXTH-61. COMBINATION OF DISULFIRAM AND COPPER INDUCES NPL4 AGGREGATION, TARGETS CD133-NESTIN CELLS AND EXTENDS SURVIVAL IN MEDULLOBLASTOMA GROUP 3 MODELS

BACKGROUND

Medulloblastoma (MB), the most common brain malignancy among children, is classified into four molecular subtypes, WNT-driven, Shh-driven, Group 3 and 4. The aim of this study was to assess the effects of the combination of Disulfiram, an inhibitor of Aldehyde Dehydrogenase, and Copper in Shh-driven and Group 3 MB, in vitro and in vivo.

METHODS

The mechanisms of action and anti-cancer stem-cell effects of disulfiram were evaluated with clonogenic assays, flow-cytometry (FC), western blotting (WB), and immunofluorescence (IF) using established MB cell-lines - ONS76, UW228, D425med, D341 and D283- representing the main molecular subtypes. Survival, tumor volume, nuclear protein localization protein-4-expression (NPL4) and markers of proliferation/apoptosis were assessed in multiple models of Group 3 MB in vivo and ex vivo with WB and immunohistochemistry (IHC).

RESULTS

Significant in vitro cytotoxicity was demonstrated at nanomolar concentrations of DSF in all lines. DSF/Cu++ induced cell death (increased AnnV/PI, cleaved-Poly(ADP-ribose)polymerase fraction, and Apoptosis Inducing Factor on WB/FC/IF, in vitro and ex vivo) through NPL4 accumulation in cell nucleus and intracellular buildup of poly-ubiquitylated proteins. DNA damage was also detected with WB and H2AX foci on immunofluorescence. Flow-cytometry analysis demonstrated a significant reduction in ALDH, Nestin- and CD133-positive cells in Group 3 lines, confirmed with WB in vitro and ex vivo. DSF/Cu++-toxicity was tested in vivo in multiple dose-escalating trials, and the combination significantly prolonged survival and reduced tumor volume in D425 and D341 xenografts. IHC showed lower Ki67 and increased Cleaved-Caspase-3 expression, higher NPL4-positive cells and no difference in NeuN and GFAP-positive cells after treatment.

CONCLUSIONS

DSF/Cu++ demonstrated a potent therapeutic effect on Shh-driven and Group 3 MB cell lines by determining apoptosis, targeting cancer stem cells and inducing DNA damage. Our data suggest that this combination may serve as a novel treatment, alone or with existing therapies, for pediatric MB.

NCOG-06. A NOVEL ONLINE CALCULATOR PREDICTING SHORT-TERM POSTOPERATIVE OUTCOMES IN METASTATIC BRAIN CANCER PATIENTS

BACKGROUND

Establishing predictors of hospital length of stay (LOS), discharge deposition, and total hospital charges is essential to providing high-quality, value-based care. Though previous research has investigated these outcomes for patients with metastatic brain tumors, there are currently no tools that synthesize such research findings and allow for prediction of these outcomes on a patient-by-patient basis.

OBJECTIVE

We sought to develop a prediction calculator that uses patient demographic and clinical information to predict extended hospital length of stay, nonroutine discharge disposition, and high total hospital charges for patients with metastatic brain tumors.

METHODS

Patients undergoing surgery for metastatic brain tumors at a single academic institution were analyzed (2017-2019). Multivariate logistic regression was used to identify independent predictors of extended LOS (&gt; 8 days), nonroutine discharge, and high total hospital charges (&gt; $45,660.00). p &lt; 0.05 was considered statistically significant. C-statistics and the Hosmer-Lemeshow test were used to assess model discrimination and calibration, respectively.

RESULTS

A total of 222 patients were included in our analysis, with a mean age of 62.2 years. The majority of patients were male (52.7%) and Caucasian (76.6%). Our models predicting extended LOS, nonroutine discharge, and high hospital charges had optimism-corrected c-statistics &gt; 0.7, and all three models demonstrated adequate calibration (p &gt; 0.05). The final models are available as an online calculator (https://neurooncsurgery.shinyapps.io/mets_brain_cancer_calculator/).

CONCLUSIONS

Our models predicting postoperative outcomes allow for individualized risk-estimation for patients following surgery for metastatic brain cancer. Our results may be useful in helping clinicians to provide high-value care and to ensure optimal patient outcomes

A novel online calculator predicting short-term postoperative outcomes in patients with metastatic brain tumors

Purpose

Establishing predictors of hospital length of stay (LOS), discharge deposition, and total hospital charges is essential to providing high-quality, value-based care. Though previous research has investigated these outcomes for patients with metastatic brain tumors, there are currently no tools that synthesize such research findings and allow for prediction of these outcomes on a patient-by-patient basis. The present study sought to develop a prediction calculator that uses patient demographic and clinical information to predict extended hospital length of stay, non-routine discharge disposition, and high total hospital charges for patients with metastatic brain tumors.

Methods

Patients undergoing surgery for metastatic brain tumors at a single academic institution were analyzed (2017–2019). Multivariate logistic regression was used to identify independent predictors of extended LOS (> 7 days), non-routine discharge, and high total hospital charges (> $ 46,082.63). p < 0.05 was considered statistically significant. C-statistics and the Hosmer–Lemeshow test were used to assess model discrimination and calibration, respectively.

Results

A total of 235 patients were included in our analysis, with a mean age of 62.74 years. The majority of patients were female (52.3%) and Caucasian (76.6%). Our models predicting extended LOS, non-routine discharge, and high hospital charges had optimism-corrected c-statistics > 0.7, and all three models demonstrated adequate calibration (p > 0.05). The final models are available as an online calculator (https://neurooncsurgery.shinyapps.io/brain_mets_calculator/).

Conclusions

Our models predicting postoperative outcomes allow for individualized risk-estimation for patients following surgery for metastatic brain tumors. Our results may be useful in helping clinicians to provide resource-conscious, high-value care.

Abstract 6268: Use of the anti-viral drug ribavirin as a radiosensitizing agent in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a squamous cell carcinoma with a propensity for metastasis, leading many patients to fail available treatments and/or present with advanced-stage disease. There is currently a scarcity of targeted therapies for NPC, despite working knowledge of several proteins with key roles in NPC cancer biology. These include EZH2, Snail, eIF4E, and IMPDH, which are all overexpressed in NPC and correlated with poor patient prognosis. These proteins are known to be targeted by ribavirin, a well-characterized anti-viral drug that has recently been repurposed as an anti-cancer agent in several solid and hematologic malignancies. In the present study, we investigated the potential of ribavirin as a targeted therapy and radiosensitizing agent in five human NPC cell lines. We show in vitro, using cellular growth assays, flow cytometry, BrdU cell proliferation assays, scratch wound assays, and invasion assays, that ribavirin decreases NPC cellular proliferation, migration, and invasion and promotes cell cycle arrest and cell death. Modulation of EZH2, Snail, eIF4E, IMPDH, and mTOR were observed in western blots and enzymatic activity assays in response to ribavirin treatment. In vivo, monotherapy with ribavirin reduced flank tumor growth in multiple NPC xenograft models. Given that radiation therapy is a mainstay of NPC treatment, we next investigated the effects of combining ribavirin with radiation. Using clonogenic assays and flow cytometry, we demonstrate that ribavirin enhanced the cytotoxic effects of radiation on NPC cells in vitro. Most importantly, using a flank tumor xenograft model, we show that pre-treatment with ribavirin potentiated the effects of radiation therapy in vivo. Our work suggests that NPC responds to ribavirin-mediated EZH2, Snail, eIF4E, IMPDH, and mTOR modulation and positions ribavirin for clinical evaluation as a targeted therapy and radiosensitizing agent in this cancer.

Citation Format: Sakibul Huq, Joshua Casaos, Riccardo Serra, Michael Peters, Yuanxuan Xia, Andy Ding, Jeffrey Ehresman, Jayanidhi Kedda, Manuel Morales, Noah Gorelick, Tianna Zhao, Wataru Ishida, Alexander Perdomo-Pantoja, Arba Cecia, Chenchen Ji, Ian Suk, David Sidransky, Mariana Brait, Henry Brem, Nicolas Skuli, Betty Tyler. Use of the anti-viral drug ribavirin as a radiosensitizing agent in nasopharyngeal carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6268.

76. THE ROLE OF FRAILTY IN PREDICTING POSTOPERATIVE SOCIOECONOMIC OUTCOMES AMONG PATIENTS WITH METASTATIC BRAIN CANCER

BACKGROUND

Patient frailty is an important consideration in the context of providing high-value, cost-effective care, as it has shown to effectively predict postoperative morbidity and mortality in many surgical subspecialties. However, for metastatic cancer patients, there is a lack of consensus as to whether frailty effectively predicts postoperative outcomes such as survival and length of stay (LOS), specifically among patients with metastatic brain tumors.

OBJECTIVE

The present study sought to determine if the 5-factor modified frailty index (mFI-5) independently predicts LOS, discharge disposition, and total hospital charges among patients with metastatic brain cancer.

METHODS

Patients diagnosed with metastatic brain cancer who underwent surgery between 2017–2019 at a single academic institution were analyzed. Bivariate analysis identified patient characteristics significantly associated of LOS, discharge disposition, and total hospital charges. Multivariate linear regression was used to identify independent predictors of LOS and total hospital charges, while multivariate logistic regression was used to identify independent predictors of non-routine discharge disposition. P &lt;0.05 was considered statistically significant.

RESULTS

A total of 302 patients were included in our analysis. Our patient cohort had a mean age (standard deviation) of 62.27 11.86 years, and was majority female (52.0%) and Caucasian (74.2%). The majority of patients had a primary lung cancer (24.8%), followed by breast cancer (13.6%). There was no significant difference in mFI-5 score between patients with metastatic tumors of known origin compared to patients with metastatic tumors of unknown origin (p=0.61). In multivariate analysis, a higher mFI-5 score independently predicted longer LOS (regression coefficient [Coef]=1.36 days, p&lt;0.001), non-routine discharge disposition (odds ratio [OR]=1.60, p=0.0079), and higher total hospital charges (Coef=$4325.54, p=0.0010).

CONCLUSION

The mFI-5 independently predicts LOS, discharge disposition, and total hospital charges among our cohort of metastatic brain cancer patients. Our findings may be used to aid physicians in providing high-value neurosurgical care.

The 5-factor modified frailty index: an effective predictor of mortality in brain tumor patients

OBJECTIVE

Health measures such as the Charlson Comorbidity Index (CCI) and the 11-factor modified frailty index (mFI-11) have been employed to predict general medical and surgical mortality, but their clinical utility is limited by the requirement for a large number of data points, some of which overlap or require data that may be unavailable in large datasets. A more streamlined 5-factor modified frailty index (mFI-5) was recently developed to overcome these barriers, but it has not been widely tested in neuro-oncology patient populations. The authors compared the utility of the mFI-5 to that of the CCI and the mFI-11 in predicting postoperative mortality in brain tumor patients.

METHODS

The authors retrospectively reviewed a cohort of adult patients from a single institution who underwent brain tumor surgery during the period from January 2017 to December 2018. Logistic regression models were used to quantify the associations between health measure scores and postoperative mortality after adjusting for patient age, race, ethnicity, sex, marital status, and diagnosis. Results were considered statistically significant at p values ≤ 0.05. Receiver operating characteristic (ROC) curves were used to examine the relationships between CCI, mFI-11, and mFI-5 and mortality, and DeLong’s test was used to test for significant differences between c-statistics. Spearman’s rho was used to quantify correlations between indices.

RESULTS

The study cohort included 1692 patients (mean age 55.5 years; mean CCI, mFI-11, and mFI-5 scores 2.49, 1.05, and 0.80, respectively). Each 1-point increase in mFI-11 (OR 4.19, p = 0.0043) and mFI-5 (OR 2.56, p = 0.018) scores independently predicted greater odds of 90-day postoperative mortality. Adjusted CCI, mFI-11, and mFI-5 ROC curves demonstrated c-statistics of 0.86 (CI 0.82–0.90), 0.87 (CI 0.83–0.91), and 0.87 (CI 0.83–0.91), respectively, and there was no significant difference between the c-statistics of the adjusted CCI and the adjusted mFI-5 models (p = 0.089) or between the adjusted mFI-11 and the adjusted mFI-5 models (p = 0.82). The 3 indices were well correlated (p < 0.01).

CONCLUSIONS

The adjusted mFI-5 model predicts 90-day postoperative mortality among brain tumor patients as well as our adjusted CCI and adjusted mFI-11 models. The simplified mFI-5 may be easily integrated into clinical workflows to predict brain tumor surgery outcomes in real time.

Predictors of Nonroutine Discharge Disposition Among Patients with Parasagittal/Parafalcine Meningioma

OBJECTIVE

Discharge disposition is an important outcome for neurosurgeons to consider in the context of high-quality, value-based care. There has been limited research into how the unique anatomic considerations associated with parasagittal/parafalcine meningioma resection may influence discharge disposition. We investigated the effects of various predictors on discharge disposition within a cohort of patients with parasagittal/parafalcine meningioma.

METHODS

A total of 154 patients treated at a single institution were analyzed (2016-2019). Bivariate analysis was conducted using the Mann-Whitney U and Fisher exact tests. Multivariate analysis was conducted using logistic regression. An optimism-corrected C-statistic was calculated using 2000 bootstrap samples to assess logistic regression model performance.

RESULTS

Our cohort was mostly female (67.5%) and white (72.7%), with a mean age of 57.29 years. Most patients had tumors associated with the middle third of the superior sagittal sinus (SSS) (60.4%) and had tumors that were not fully occluding the SSS (74.0%). In multivariate analysis, independent predictors of nonroutine discharge disposition included 5-factor Modified Frailty Index score (odds ratio [OR], 2.06; P = 0.0088), Simpson grade IV resection (OR, 4.22; P = 0.0062), and occurrence of any postoperative complication (OR, 2.89; P = 0.031). The optimism-corrected C-statistic of our model was 0.757.

CONCLUSIONS

In our single-institution experience, neither extent of SSS invasion nor location along the SSS predicted nonroutine discharge, suggesting that tumor invasion and posterior location along the SSS are not necessarily contraindications to surgery. Our results also highlight the importance of frailty and tumor size in stratifying patients at risk of nonroutine discharge disposition.