Distribution of rupture sites and blebs on intracranial aneurysm walls suggests distinct rupture patterns in ACom and MCA aneurysms.

The mechanisms behind intracranial aneurysm formation and rupture are not fully understood, with factors such as location, patient demographics, and hemodynamics playing a role. Additionally, the significance of anatomical features like blebs in ruptures is debated. This highlights the necessity for comprehensive research that combines patient-specific risk factors with a detailed analysis of local hemodynamic characteristics at bleb and rupture sites. Our study analyzed 359 intracranial aneurysms from 268 patients, reconstructing patient-specific models for hemodynamic simulations based on 3D rotational angiographic images and intraoperative videos. We identified aneurysm subregions and delineated rupture sites, characterizing blebs and their regional overlap, employing statistical comparisons across demographics, and other risk factors. This work identifies patterns in aneurysm rupture sites, predominantly at the dome, with variations across patient demographics. Hypertensive and anterior communicating artery (ACom) aneurysms showed specific rupture patterns and bleb associations, indicating two pathways: high-flow in ACom with thin blebs at impingement sites and low-flow, oscillatory conditions in middle cerebral artery (MCA) aneurysms fostering thick blebs. Bleb characteristics varied with gender, age, and smoking, linking rupture risks to hemodynamic factors and patient profiles. These insights enhance understanding of the hemodynamic mechanisms leading to rupture events. This analysis elucidates the role of localized hemodynamics in intracranial aneurysm rupture, challenging the emphasis on location by revealing how flow variations influence stability and risk. We identify two pathways to wall failure-high-flow and low-flow conditions-highlighting the complexity of aneurysm behavior. Additionally, this research advances our knowledge of how inherent patient-specific characteristics impact these processes, which need further investigation.

Cost of Treatment for Brain Metastases Using Data From a National Health Insurance.

Purpose: In the United States, brain metastases (BMs) affect 10% to 20% of patients with cancer, presenting a significant health care challenge and necessitating intricate, high-cost treatments. Few studies have explored the comprehensive care cost for BMs, and none have used real insurance claims data. Partnering with a northeastern health care insurer, we investigated the true costs of various brain-directed radiation methods, aiming to shed light on treatment expenses, modalities, and their efficacy. Methods and Materials: We analyzed medical claims from Highmark Health-insured patients in Pennsylvania, Delware, West Virginia, and New York diagnosed with BMs (ICD-10 code C79.31) and treated with radiation from January 1, 2020 to July 1, 2022. Costs for radiation techniques were grouped by specific current procedural terminology claim codes. We subdivided costs into technical and physician components and separated hospital from freestanding costs for some modalities. Results: From January 1, 2020 to July 1, 2022, 1048 Highmark Health members underwent treatment for BMs. Females (n = 592) significantly outnumbered males (n = 456), with an average age of 64.4 years. Each member had, on average, 5.309 claims costing $2015 per claim. Total cost totaled $10,697,749. Per-treatment analysis showed that hippocampal avoidance intensity modulated radiation therapy was the costliest treatment at $47,748, followed by stereotactic radiation therapy at $37,230, linear accelerator stereotactic radiosurgery (SRS) at $30,737, Gamma Knife SRS at $30,711, and whole-brain radiation therapy at $5225. Conclusions: Whole-brain radiation therapy was the least costly radiation technique. Similar per-treatment prices for Gamma Knife and linear accelerator SRS support their use in treating BMs. Stereotactic radiation therapy in general was costlier on a per-use basis than SRS, prompting further scrutiny on its frequent use. Hippocampal avoidance intensity modulated radiation therapy was the costliest radiation therapy on a per-use basis by a moderate amount, prompting further discussion about its comparative cost effectiveness against other radiation modalities. This study underscores the importance of multiple considerations in treating BMs, such as tumor control, survival, side effects, and costs.

Occipital-interhemispheric transtentorial pineal mass resection.

The occipital approach for pineal tumors was first described by James Poppen in 1966. Since then, it has been widely used for accessing deep-seated tumors as it offers a wider surgical view than the supracerebellar transtentorial approach. This video demonstrates the technical nuances of the occipital transtentorial approach and the exoscopic dissection of a pineal gland tumor in a 66-year-old male. Use of the exoscope over the microscope provides certain ergonomic advantages and improves surgical workflow, as demonstrated here. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23161.

The 5-factor modified frailty index as a prognostic factor of stereotactic radiosurgery for metastatic disease to the brain.

OBJECTIVE: Frailty, a state of increased vulnerability to adverse health outcomes, is associated with poor neurosurgical outcomes. The relationship between frailty and stereotactic radiosurgery (SRS) for brain metastases (BMs), however, has not been adequately described. In this study, the authors attempted to examine the connection between frailty and outcomes for patients receiving SRS for BMs. METHODS: A single-center retrospective cohort study was performed. The 5-factor modified frailty index (mFI-5) was used to stratify patients into pre-frail (mFI-5 score 0-1), frail (mFI-5 score 2), and severely frail (mFI-5 score ≥ 3) cohorts at the time of SRS treatment. Both overall survival (OS) and progression-free survival (PFS) were evaluated. Factors associated with OS/PFS were assessed using Kaplan-Meier analysis and a Cox proportional hazards model. RESULTS: Two hundred three patients met the inclusion criteria and received SRS to one or more BMs. Fifty-six patients (27.6%) received SRS as an adjuvant treatment. The 12-month OS and PFS rates were 58.6% and 45.5%, respectively. One hundred twenty-six patients (62.1%) were classified as pre-frail, 58 (28.6%) as frail, and 19 (9.4%) as severely frail. Significantly less OS was demonstrated in frailer groups (frail hazard ratio [HR] 3.14, p < 0.005; severely frail HR 3.13, p < 0.005). Compared with pre-frail patients, frail patients had shorter intervals of PFS (frail HR 2.05, p < 0.005). Five patients (2.5%) had symptomatic radiation necrosis (RN) and 60 (29.6%) required repeat radiation. CONCLUSIONS: Higher frailty scores at the time of SRS treatment were predictive of shorter OS and PFS intervals.

Artificially Intelligent Billing in Spine Surgery: An Analysis of a Large Language Model.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study assessed the effectiveness of a popular large language model, ChatGPT-4, in predicting Current Procedural Terminology (CPT) codes from surgical operative notes. By employing a combination of prompt engineering, natural language processing (NLP), and machine learning techniques on standard operative notes, the study sought to enhance billing efficiency, optimize revenue collection, and reduce coding errors. METHODS: The model was given 3 different types of prompts for 50 surgical operative notes from 2 spine surgeons. The first trial was simply asking the model to generate CPT codes for a given OP note. The second trial included 3 OP notes and associated CPT codes to, and the third trial included a list of every possible CPT code in the dataset to prime the model. CPT codes generated by the model were compared to those generated by the billing department. Model evaluation was performed in the form of calculating the area under the ROC (AUROC), and area under precision-recall curves (AUPRC). RESULTS: The trial that involved priming ChatGPT with a list of every possible CPT code performed the best, with an AUROC of .87 and an AUPRC of .67, and an AUROC of .81 and AUPRC of .76 when examining only the most common CPT codes. CONCLUSIONS: ChatGPT-4 can aid in automating CPT billing from orthopedic surgery operative notes, driving down healthcare expenditures and enhancing billing code precision as the model evolves and fine-tuning becomes available.

The Role of FAS Receptor Methylation in Osteosarcoma Metastasis.

Osteosarcoma is the most frequent primary malignant bone tumor with an annual incidence of about 400 cases in the United States. Osteosarcoma primarily metastasizes to the lungs, where FAS ligand (FASL) is constitutively expressed. The interaction of FASL and its cell surface receptor, FAS, triggers apoptosis in normal cells; however, this function is altered in cancer cells. DNA methylation has previously been explored as a mechanism for altering FAS expression, but no variability was identified in the CpG island (CGI) overlapping the promoter. Analysis of an expanded region, including CGI shores and shelves, revealed high variability in the methylation of certain CpG sites that correlated significantly with FAS mRNA expression in a negative manner. Bisulfite sequencing revealed additional CpG sites, which were highly methylated in the metastatic LM7 cell line but unmethylated in its parental non-metastatic SaOS-2 cell line. Treatment with the demethylating agent, 5-azacytidine, resulted in a loss of methylation in CpG sites located within the FAS promoter and restored FAS protein expression in LM7 cells, resulting in reduced migration. Orthotopic implantation of 5-azacytidine treated LM7 cells into severe combined immunodeficient mice led to decreased lung metastases. These results suggest that DNA methylation of CGI shore sites may regulate FAS expression and constitute a potential target for osteosarcoma therapy, utilizing demethylating agents currently approved for the treatment of other cancers.

Treatment of unmethylated MGMT-promoter recurrent glioblastoma with cancer stem cell assay-guided chemotherapy and the impact on patients' healthcare costs.

Background: Glioblastoma (GBM) is a lethal disease. At least in part, the recurrence of GBM is caused by cancer stem cells (CSCs), which are resistant to chemotherapy. Personalized anticancer therapy against CSCs can improve treatment outcomes. We present a prospective cohort study of 40 real-world unmethylated Methyl-guanine-methyl-transferase-promoter GBM patients treated utilizing a CSC chemotherapeutics assay-guided report (ChemoID). Methods: Eligible patients who underwent surgical resection for recurrent GBM were included in the study. Most effective chemotherapy treatments were chosen based on the ChemoID assay report from a panel of FDA-approved chemotherapies. A retrospective chart review was conducted to determine OS, progression-free survival, and the cost of healthcare costs. The median age of our patient cohort was 53 years (24-76). Results: Patients treated prospectively with high-response ChemoID-directed therapy, had a median overall survival (OS) of 22.4 months (12.0-38.4) with a log-rank P = .011, compared to patients who could be treated with low-response drugs who had instead an OS of 12.5 months (3.0-27.4 months). Patients with recurrent poor-prognosis GBM treated with high-response therapy had a 63% probability to survive at 12 months, compared to 27% of patients who were treated with low-response CSC drugs. We also found that patients treated with high-response drugs on average had an incremental cost-effectiveness ratio (ICER) of $48,893 per life-year saved compared to $53,109 of patients who were treated with low-response CSC drugs. Conclusions: The results presented here suggest that the ChemoID Assay can be used to individualize chemotherapy choices to improve poor-prognosis recurrent GBM patient survival and to decrease the healthcare cost that impacts these patients.

Cancer stem cell assay-guided chemotherapy improves survival of patients with recurrent glioblastoma in a randomized trial.

Therapy-resistant cancer stem cells (CSCs) contribute to the poor clinical outcomes of patients with recurrent glioblastoma (rGBM) who fail standard of care (SOC) therapy. ChemoID is a clinically validated assay for identifying CSC-targeted cytotoxic therapies in solid tumors. In a randomized clinical trial (NCT03632135), the ChemoID assay, a personalized approach for selecting the most effective treatment from FDA-approved chemotherapies, improves the survival of patients with rGBM (2016 WHO classification) over physician-chosen chemotherapy. In the ChemoID assay-guided group, median survival is 12.5 months (95% confidence interval [CI], 10.2-14.7) compared with 9 months (95% CI, 4.2-13.8) in the physician-choice group (p = 0.010) as per interim efficacy analysis. The ChemoID assay-guided group has a significantly lower risk of death (hazard ratio [HR] = 0.44; 95% CI, 0.24-0.81; p = 0.008). Results of this study offer a promising way to provide more affordable treatment for patients with rGBM in lower socioeconomic groups in the US and around the world.

An Immunologic and Biomechanical Comparison of Polyether Ether Ketone-Zeolite and Polyether Ether Ketone Interbody Fusion Devices.

STUDY DESIGN: A laboratory study comparing polyether ether ketone (PEEK)-zeolite and PEEK spinal implants in an ovine model. OBJECTIVE: This study challenges a conventional spinal implant material, PEEK, to PEEK-zeolite using a nonplated cervical ovine model. SUMMARY OF BACKGROUND DATA: Although widely used for spinal implants due to its material properties, PEEK is hydrophobic, resulting in poor osseointegration, and elicits a mild nonspecific foreign body response. Zeolites are negatively charged aluminosilicate materials that are hypothesized to reduce this pro-inflammatory response when used as a compounding material with PEEK. MATERIALS AND METHODS: Fourteen skeletally mature sheep were, each, implanted with one PEEK-zeolite interbody device and one PEEK interbody device. Both devices were packed with autograft and allograft material and randomly assigned to one of 2 cervical disc levels. The study involved 2 survival time points (12 and 26 weeks) and biomechanical, radiographic, and immunologic endpoints. One sheep expired from complications not related to the device or procedure. A biomechanical evaluation was based on measures of segmental flexibility, using 6 degrees of freedom pneumatic spine tester. Radiographic evaluation was performed using microcomputed tomography scans in a blinded manner by 3 physicians. Levels of the pro-inflammatory cytokines, interleukin (IL)-1ß, IL-6, and tumor necrosis factor-alpha at the implant, were quantified using immunohistochemistry. RESULTS: PEEK-zeolite and PEEK exhibited an equivalent range of motion in flexion extension, lateral bending, and axial torsion. A motion was significantly reduced for implanted devices at both time points as compared with native segments. Radiographic assessments of fusion and bone formation were similar for both devices. PEEK-zeolite exhibited lower levels of IL-1ß ( P = 0.0003) and IL-6 ( P = 0.03). CONCLUSION: PEEK-zeolite interbody fusion devices provide initial fixation substantially equivalent to PEEK implants but exhibit a reduced pro-inflammatory response. PEEK-zeolite devices may reduce the chronic inflammation and fibrosis previously observed with PEEK devices.

A Comparison of Single Fraction and Multi Fraction Radiosurgery on the Gamma Knife ICON: A Single Institution Review.

Purpose: Brain metastases are a common development in patients with malignant solid tumors. Stereotactic radiosurgery (SRS) has a long track record of effectively and safely treating these patients, with some limitations to the use of single fraction SRS based on size and volume. In this study, we reviewed outcomes of patients treated using SRS and fractionated SRS (fSRS) to compare predictors and outcomes of those treatments. Methods and Materials: Two hundred patients treated with SRS or fSRS for intact brain metastases were included. We tabulated baseline characteristics and performed a logistic regression to identify predictors of fSRS. Cox regression was used to identify predictors of survival. Kaplan-Meier analysis was used to calculate survival, local failure, and distant failure rates. A receiver operating characteristic curve was generated to determine timepoint from planning to treatment associated with local failure. Results: The only predictor of fSRS was tumor volume >2.061 cm3. There was no difference in local failure, toxicity, or survival by fractionation of biologically effective dose. Predictors of worse survival were age, extracranial disease, history of whole brain radiation therapy, and volume. Receiver operating characteristic analysis identified 10 days as potential factor in local failure. At 1 year, local control was 96.48 and 76.92% for those patients treated before or after that interval, respectively (P = .0005). Conclusions: Fractionated SRS is a safe and effective alternative for patients with larger volume tumors not suitable for single fraction SRS. Care should be taken to treat these patients expeditiously as a delay was shown to affect local control in this study.

A Multicenter Study Investigating the Surgeon Experience with a Robotic-Assisted Exoscope as Part of the Neurosurgical Armamentarium.

BACKGROUND: Improvement of visualization tools in neurosurgery such as the exoscope has raised the question of how this technology compares to the conventional microscope for surgeon ergonomics, discomfort, and patient outcomes. Exoscopes have the advantage of greater optical zoom, resolution, and illumination at a lower light intensity. Heads-up display for both the primary surgeon and other assistants permits neutral positioning of the surgeons while placing the camera in more angled positions. In a survey sample, this study assesses the surgeon experience utilizing 3D exoscope in general neurosurgery cases. METHODS: Data weere recorded by 8 surgeons at 5 separate hospitals utilizing a mobile phone application survey. Surgeons recorded information about case type, intraoperative clinical outcomes such as blood loss and extent of resection, whether fluorescence visualization was used, as well as surgeon pain when compared to matched cases using conventional tools. RESULTS: A total of 155 neurosurgical cases were recorded in this multisite study, including 72% cranial cases and 28% spinal cases. Of the cranial cases, 76% were brain tumor resections (31% of which were brain metastases). Surgeons reported significantly less neck (P < 0.0001) and back (P < 0.0001) pain in cases when using the robotic exoscope compared with the conventional microscope or surgical loupes. Surgeons did not convert to a microscope in any case. CONCLUSIONS: The exoscope provides excellent delineation of tissue with high resolution. Surgeon pain was markedly reduced with the robotic exoscope when compared with conventional technology, which may reduce work-related injury and fatigue, potentially leading to better patient outcomes.

Mycotic aneurysm presenting as subdural empyema: illustrative case.

BACKGROUND: Mycotic aneurysms (MAs) are rare intracranial pathologies. They are associated with spontaneous rupture, which is often the first presenting sign. Subarachnoid hemorrhage and intraparenchymal hemorrhage are the most common sequelae of ruptured MAs, with subdural hematoma being an atypical presentation. The presentation of an MA as a subdural empyema has not yet been reported in the literature. OBSERVATIONS: The authors discussed a 68-year-old man who presented with subdural empyema and received surgery for evacuation. He was found to have a ruptured mycotic aneurysm intraoperatively. LESSONS: This case demonstrated a rare and atypical presentation of an MA.

Integrated DNA Copy Number and Expression Profiling Identifies IGF1R as a Prognostic Biomarker in Pediatric Osteosarcoma.

Osteosarcoma is a primary malignant bone tumor arising from bone-forming mesenchymal cells in children and adolescents. Despite efforts to understand the biology of the disease and identify novel therapeutics, the survival of osteosarcoma patients remains dismal. We have concurrently profiled the copy number and gene expression of 226 osteosarcoma samples as part of the Strategic Partnering to Evaluate Cancer Signatures (SPECS) initiative. Our results demonstrate the heterogeneous landscape of osteosarcoma in younger populations by showing the presence of genome-wide copy number abnormalities occurring both recurrently among samples and in a high frequency. Insulin growth factor receptor 1 (IGF1R) is a receptor tyrosine kinase which binds IGF1 and IGF2 to activate downstream pathways involved in cell apoptosis and proliferation. We identify prevalent amplification of IGF1R corresponding with increased gene expression in patients with poor survival outcomes. Our results substantiate previously tenuously associated copy number abnormalities identified in smaller datasets (13q34+, 20p13+, 4q35-, 20q13.33-), and indicate the significance of high fibroblast growth factor receptor 2 (FGFR2) expression in distinguishing patients with poor prognosis. FGFR2 is involved in cellular proliferation processes such as division, growth and angiogenesis. In summary, our findings demonstrate the prognostic significance of several genes associated with osteosarcoma pathogenesis.

Case Series of Skull Base Meningioma Resection in the Octogenarian Population.

Introduction The geriatric population is the fastest growing segment of the American population, and octogenarians are increasingly seen by neurosurgeons for relatively common lesions such as meningiomas. Unfortunately, providers do not have clear data to guide decision-making regarding these lesions, particularly if they involve the skull base. Current research in outcomes among the elderly looks at a wide range of ages, often anyone older than 65. Previous studies in octogenarians report a wide-range of mortality rates and do not focus on skull base lesions. This paper strives to clarify the experiences and outcomes of octogenarians. Patients and Methods This retrospective series reviews skull base tumor surgeries performed at a single academic institution over the past 15 years in octogenarian patients. Primary endpoint was 30-day mortality; however, potential risk factors, perioperative morbidity, postdischarge disposition, and longer term follow-up were also captured. Multivariate logistic regression was performed to identify relevant perioperative and medical characteristics that increases the risk of adverse events. Results Fourteen patients underwent craniotomies for skull base procedures with an average age of 84.5, with a 14% 30-day mortality rate. One patient required a tracheostomy on discharge and approximately half were able to either go home or rehabilitation after their procedure. On statistical analysis, there were no noted characteristics that predisposed any of the patients to a poorer outcome. Conclusion Octogenarian patients were able to tolerate surgery for skull base meningiomas resection. This outcome data may be used to inform surgical decision and guide conversation with patients and their families.

Characterizing molecular subtypes of high-risk non-muscle-invasive bladder cancer in African American patients.

BACKGROUND: We sought to determine whether differences in subtype distribution and differentially expressed genes exist between African Americans (AAs) and European Americans (EAs) in patients with high-risk nonmuscle-invasive bladder cancer (NMIBC). METHODS: We performed a retrospective cohort study including 26 patients (14 AAs and 12 EAs) from the University of Texas Medical Branch and the Durham Veterans Affair Health Care System from 2010 to 2020 among treatment naïve, high-risk NMIBC. Profiled gene expressions were performed using the UROMOL classification system. RESULTS: UROMOL racial subtype distributions were similar with class 2a being most common with 10 genes commonly upregulated in AAs compared to EAs including EFEMP1, S100A16, and MCL1 which are associated with progression to muscle-invasive bladder cancer, mitomycin C resistance, and bacillus Calmette-Guérin durability, respectively. We used single nuclei analysis to map the malignant cell heterogeneity in urothelial cancer which 5 distinct malignant epithelial subtypes whose presence has been associated with different therapeutic response prediction abilities. We mapped the expression of the 10 genes commonly upregulated by race as a function of the 5 malignant subtypes. This showed borderline (P = 0.056) difference among the subtypes suggesting AAs and EAs may be expected to have different therapeutic responses to treatments for bladder cancer. AAs were enriched with immune-related, inflammatory, and cellular regulation pathways compared to EAs, yet appeared to have reduced levels of the aggressive C3/CDH12 bladder tumor cell population. CONCLUSIONS: While premature, gene expression differed between AAs and EAs, supporting potential race-based etiologies for muscle-invasion, response to treatments, and transcriptome pathway regulations.

Trends in the use of radiation for meningioma across the United States.

PURPOSE: Meningiomas are tumors originating from arachnoid cap cells on the surface of the brain or spinal cord. Treatment differs by grade but can consist of observation, surgery, radiation therapy or both. We utilized the National Cancer Database (NCDB) to compare trends in the use stereotactic radiosurgery (SRS) and external beam radiation therapy (EBRT) in the management of meningioma. MATERIALS AND METHODS: We queried the NCDB from 2004-2015 for meningioma patients (grade 1-3) treated with radiation therapy, either SRS or EBRT. Multivariable logistic regression was used to identify predictors of each treatment and to generate a propensity score. Propensity adjusted Kaplan-Meier survival curve analysis and multivariable Cox hazards ratios were used to identify predictors of survival. RESULTS: We identified 5,406 patients with meningioma meeting above criteria with 45%, 44%, and 11% having World Health Organization (WHO) grade 1, 2, and 3 disease, respectively. Median follow up was 43 months. Predictors for SRS were grade 1 disease, distance from treatment facility, and histology. The only predictor of EBRT was grade 3 disease. Treatment year, histology, race and female sex were associated with improved survival. Five- and 10-year survival rates were 89.2% versus 72.6% (p < 0.0001) and 80.3% versus 61.4% (p = 0.29) for SRS and EBRT respectively. After propensity matching 226 pairs were generated. For SRS, 5-year survival was not significantly improved at 88.2% compared with EBRT (p = 0.056). CONCLUSION: In the present analysis, predictors of SRS utilization in management of meningioma include WHO grade 1 disease, distance from treatment facility and histology whereas conventional EBRT utilization was associated with grade 2 and 3 disease. Future studies need to be performed in order to optimize management of atypical and malignant meningioma.

Real-time vessel segmentation and reconstruction for virtual fixtures for an active handheld microneurosurgical instrument.

PURPOSE: Complications related to vascular damage such as intra-operative bleeding may be avoided during neurosurgical procedures such as petroclival meningioma surgery. To address this and improve the patient's safety, we designed a real-time blood vessel avoidance strategy that enables operation on deformable tissue during petroclival meningioma surgery using Micron, a handheld surgical robotic tool. METHODS: We integrated real-time intra-operative blood vessel segmentation of brain vasculature using deep learning, with a 3D reconstruction algorithm to obtain the vessel point cloud in real time. We then implemented a virtual-fixture-based strategy that prevented Micron's tooltip from entering a forbidden region around the vessel, thus avoiding damage to it. RESULTS: We achieved a median Dice similarity coefficient of 0.97, 0.86, 0.87 and 0.77 on datasets of phantom blood vessels, petrosal vein, internal carotid artery and superficial vessels, respectively. We conducted trials with deformable clay vessel phantoms, keeping the forbidden region 400 [Formula: see text]m outside and 400 [Formula: see text]m inside the vessel. Micron's tip entered the forbidden region with a median penetration of just 8.84 [Formula: see text]m and 9.63 [Formula: see text]m, compared to 148.74 [Formula: see text]m and 117.17 [Formula: see text]m without our strategy, for the former and latter trials, respectively. CONCLUSION: Real-time control of Micron was achieved at 33.3 fps. We achieved improvements in real-time segmentation of brain vasculature from intra-operative images and showed that our approach works even on non-stationary vessel phantoms. The results suggest that by enabling precise, real-time control, we are one step closer to using Micron in real neurosurgical procedures.

Trends in radiation dose for low grade gliomas across the United States.

PURPOSE: Adjuvant radiation is often used in patients with low grade gliomas with high-risk characteristics with a recommended dose of 45-54 Gy. We used the National Cancer Database (NCDB) to see which doses were being used, and if any difference was seen in outcome. METHODS: We queried the NCDB for patients with WHO Grade 2 primary brain tumors treated with surgery and adjuvant radiotherapy. We divided the cohort into dose groups: 45-50 Gy, 50.4-54 Gy, and > 54 Gy. Multivariable logistic regression was used to identify predictors of low and high dose radiation. Propensity matching was used to account for indication bias. RESULTS: We identified 1437 patients meeting inclusion criteria. Median age was 45 years and 62% of patients were > 40 years old. Nearly half of patients (48%) had astrocytoma subtype and 70% had subtotal resection. The majority of patients (69%) were treated to doses between 50.4 and 54 Gy. Predictors of high dose radiation (> 54 Gy) were increased income, astrocytoma subtype, chemotherapy receipt, and treatment in later year (2014). The main predictors of survival were age > 40, astrocytoma subtype, and insurance type. Patients treated to a dose of > 54 Gy had a median survival of 73.5 months and was not reached in those treated to a lower dose (p = 0.0041). CONCLUSIONS: This analysis shows that 50.4-54 Gy is the most widely used radiation regimen for the adjuvant treatment of low-grade gliomas. There appeared to be no benefit to higher doses, although unreported factors may impact interpretation of the results.

Long term cost comparisons of radical cystectomy versus trimodal therapy for muscle-invasive bladder cancer.

BACKGROUND: Earlier studies on the cost of muscle-invasive bladder cancer treatments are limited to short-term costs of care. We determined the 2- and 5-year costs associated with trimodal therapy (TMT) vs. radical cystectomy (RC). METHODS: We performed a retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Total Medicare costs at 2 and 5 years following RC vs. TMT were compared using inverse probability of treatment-weighted propensity score models. RESULTS: A total of 2,537 patients aged 66 to 85 years were diagnosed with clinical stage T2-4a muscle-invasive bladder cancer. Total median costs for patients that received no definitive treatment(s) were $73,780 and $88,275 at 2-and 5-years. Costs were significantly higher for TMT than RC at 2-years ($372,839 vs. $191,363, Median Difference $127,815, Hodges-Lehmann Estimate (H-L) 95% Confidence Interval (CI), $112,663-$142,966) and 5-years ($424,570 vs. $253,651, Median Difference $124,466, H-L 95% CI, $105,711-$143,221). TMT had higher outpatient costs than RC (2-years: $318,221 vs. $100,900; 5-years: $367,092 vs. $146,561) with significantly higher costs with radiology, medications, pathology/laboratory, and other professional services. RC had higher inpatient costs than TMT (2-years: $62,240 vs. $33,631, Median Difference $-29,174, H-L 95% CI, $-32,364-$-25,984; 5-years: $75,499 vs. $45,223, Median Difference $-29,843, H-L 95% CI, $-33,905-$-25,781). CONCLUSIONS AND RELEVANCE: The excess spending associated with trimodal therapy vs. radical cystectomy was largely driven by outpatient expenditures. The relatively high long-term trimodal therapy costs are prime targets for cost containment strategies to optimize future value-based care.

Geographic distribution of racial differences in mortality in muscle-invasive bladder cancer patients: an opportunity for improvement.

OBJECTIVES: To determine the geographic distribution of muscle-invasive bladder cancer mortality according to race in the United States (US). African Americans (AAs) have up to two times the risk of bladder cancer mortality compared to Caucasians. Bladder cancer mortality increases exponentially once it invades the muscle. Geographic heterogeneity in bladder cancer mortality according to race remains to be determined. DESIGN: Analysis of Surveillance, Epidemiology, and End Results (SEER)-Medicare data for 6,044 patients aged 66-85 diagnosed with clinical stage T2-T4 N0M0 bladder cancer from 1 January 2002 to 31 December 2011. Fine and Gray-competing risks regression models were used to assess the association of race with bladder cancer-specific mortality (BCSM) according to tumor registry. RESULTS: Out of 6,044 patients, 5,408 (89.5%) were Caucasian, 352 (5.82%) were non-Hispanic AA, 85 (1.4%) were Hispanic, and 199 (3.29%) were other. Of the 18 registries, AAs with bladder cancer were largely concentrated in Louisiana (19%), New Jersey (17.9%), and Georgia (17.6%). New Jersey was the only registry where AAs had increased risk of BCSM than Caucasians and only for stage T2 disease: (AHR, 1.74; 95% CI 1.22-2.47, p = 0.002). According to treatment, AAs in New Jersey had worse BCSM than Caucasians when they underwent radical cystectomy (AHR, 2.05; 95% CI 1.26-3.35, p = 0.0039) and radiotherapy or chemotherapy alone (AHR, 1.55; 95% CI 1.03-2.35, p = 0.0367). CONCLUSIONS: We observed geographic variation in bladder cancer mortality which impacted only one registry with one of the largest population of AAs. These findings support further investigation into the social determinants of race (i.e., socioeconomic status and distance to healthcare facility) and culturally centered healthcare decision making which may drive these results.