OBJECTIVE The extent of resection has been shown to improve outcomes in patients with meningiomas. However, resection can be complicated by constraining local anatomy, leading to subtotal resections. An understanding of the natural history of residual tumors is necessary to better guide postsurgical management and minimize recurrence. This study seeks to identify predictors of recurrence and high growth rate following subtotal resection of intracranial meningiomas. METHODS Adult patients who underwent primary surgical resection of a WHO grade I meningioma at a tertiary care institution from 2007–2017 were retrospectively reviewed. Volumetric tumor measurements were made on patients with subtotal resections. Stepwise multivariate proportional hazards regression analyses were performed to identify factors associated with time to recurrence, as well as stepwise multivariate regression analyses to assess for factors associated with high postoperative growth rate. RESULTS Of the 141 patients (18%) who underwent radiographic subtotal resection of an intracranial meningioma during the reviewed period, 74 (52%) suffered a recurrence, in which the median (interquartile range, IQR) time to recurrence was 14 (IQR 6–34) months. Among those tumors subtotally resected, the median pre- and postoperative tumor volumes were 17.19 cm 3 (IQR 7.47–38.43 cm 3 ) and 2.31 cm 3 (IQR 0.98–5.16 cm 3 ), which corresponded to a percentage resection of 82% (IQR 68%–93%). Postoperatively, the median growth rate was 0.09 cm 3 /year (IQR 0–1.39 cm 3 /year). Factors associated with recurrence in multivariate analysis included preoperative tumor volume (hazard ratio [HR] 1.008,95% confidence interval [CI] 1.002–1.013, p = 0.008), falcine location (HR 2.215, 95% CI 1.179–4.161, p = 0.021), tentorial location (HR 2.410, 95% CI 1.203–4.829, p = 0.024), and African American race (HR 1.811, 95% CI 1.042–3.146, p = 0.044). Residual volume (RV) was associated with high absolute annual growth rate (odds ratio [OR] 1.175, 95% CI 1.078–1.280, p < 0.0001), with the maximum RV benefit at < 5 cm 3 (OR 4.056, 95% CI 1.675–9.822, p = 0.002). CONCLUSIONS By identifying predictors of recurrence and growth rate, this study helps identify potential patients with a high chance of recurrence following subtotal resection, which are those with large preoperative tumor volume, falcine location, tentorial location, and African American race. Higher RVs were associated with tumors with higher postoperative growth rates. Recurrences typically occurred 14 months after surgery.
EPID-20. TRENDS IN GLIOBLASTOMA OUTCOMES OVER TIME, GEOGRAPHIC LOCATION AND TYPE OF INTERVENTION
Abstract INTRODUCTION The management of glioblastoma (GBM) has changed over time and varies based on geographic location. Despite its universally fatal prognoses, it is unclear if GBM outcomes have changed over time, if they vary by geographic location, and differ based on type of intervention. As a result, we conducted a systematic review of the literature to identify the average survival differences of GBM patients across time, between different continents, and among various treatments. METHODS The systematic review of PubMed included glioblastoma, GBM, and survival. Inclusion criteria consisted of full-text titles with human subjects, GBM/Grade IV astrocytoma, age >18 years old, and with available survival data. RESULTS 9,162 articles were screened for survival data, 1728 were eligible, 405 complied with the inclusion criteria. Of the 405 studies, 179 (44.2%) were conducted in Europe, 151 (37.3%) in the Americas, 61 (15.1%) in Asia, 9 (2.2%) in Oceania, and 1 (0.2%) in Africa. Leading countries are the United States (33.1%), Germany (12.3%), and Italy (11.1%). Asia had the highest median survival (14.9 months), followed by Europe (13.2 months), and the United States (12.9 months) (P=0.003). Regarding treatment, survival was significantly higher after the introduction of the Stupp protocol (P< 0.001). Post-Stupp Studies had longer survival estimates (15.3 months, range: 3.8–29.6) than Pre-Stupp Studies (12.2 months, range: 2.3–28). In the included clinical trials (182), radiation (43.4%), temozolomide (25.3%), or other chemotherapies (24.2%) were the most common interventions. Clinical trial median survival estimates were significantly higher than all other studies (P< 0.017). Bevacizumab (19.3 months) and Temozolomide (15.9 months) had the longest recorded median survival estimates; while radiation (14 months), other chemotherapies, and carmustine (13.2 months) had the shortest (P=0.009). CONCLUSION This epidemiological study describes the current global state of GBM. Important differences regarding survival and treatment of patients with GBM were found.
SURG-24. A RISK SCORE FOR PREDICTING DEVELOPMENT OF DIABETES INSIPIDUS AFTER PITUITARY ADENOMA RESECTION
Abstract INTRODUCTION The development of diabetes insipidus (DI) after pituitary adenoma resection is associated with worse post-surgical morbidity and longer hospital stay. Identification of clinical predictors of development of DI would allow for appropriate stratification of patients to optimize preoperative counseling and postoperative management. METHODS We conducted a retrospective review of 349 patients who underwent pituitary adenoma resection at Johns Hopkins Hospital between 2003 and 2017. We used unadjusted and adjusted logistic regression to identify predictors of developing DI. Factors which were associated with DI development (p< 0.1), were included in our multivariable model. Factors which remained associated with DI development were then used to develop a DI risk score. RESULT: 67 (19.2%) patients developed post-surgical DI. Patients who had symptoms of prolactinoma, surgery through one nare, or were on steroid treatment were more likely to develop DI. Conversely, patients who had unilateral cavernous sinus invasion were less likely to develop DI. We used these predictors to generate the DI risk score. Patients were assigned 1 point for each risk factor (symptoms of prolactinoma, steroids, or surgery through one nare) for developing DI, but 1 point was subtracted if they had a protective factor (unilateral cavernous sinus invasion). Patients with 0 points had a 10.7% probability of developing DI, patients with 1 point had a 18.5% probability of developing DI, patients with 2 points had a 41.2% probability of developing DI, and patients with 3 points had a 44.4% probability of DI. CONCLUSIONS We identified several predictors of DI development after pituitary adenoma resection, and used these to generate a DI risk score. The DI risk score could help stratify patients’ likelihood of postsurgical DI development, although validation through larger prospective multi-center studies are needed.
SURG-34. CLINICAL PREDICTORS OF TUMOR RECURRENCE AFTER PITUITARY ADENOMA RESECTION
Abstract INTRODUCTION Repeat surgery after tumor recurrence after pituitary adenoma resection can be challenging due to formation of scar tissue and loss of surgical landmarks, which can lead to increased rates of postoperative complications. Identification of clinical predictors of tumor recurrence would allow for appropriate stratification of patients to optimize preoperative counseling and postoperative management. METHODS We conducted a retrospective review of 349 patients who underwent pituitary adenoma resection at Johns Hopkins Hospital between 2003 and 2017. We used unadjusted and adjusted logistic regression to identify predictors of tumor recurrence. Factors which were associated with tumor recurrence in univariable models (p< 0.1), were included in our multivariable model. Factors that remained significantly associated with tumor recurrence (p< 0.05) in our multivariable model were considered predictors of recurrence. RESULTS 59 (16.9%) patients developed tumor recurrence at the time of our study. Patients who had surgery through one nare, transcranial surgery, visual field deficit, larger tumor volume, bilateral cavernous sinus invasion, carotid artery invasion, and postoperative cerebral spinal fluid (CSF) leak were more likely to have tumor recurrence. Conversely, patients who are younger in age, had sphenoid packing, and gross total resection were less likely to have tumor recurrence. In our multivariable model, only age (adjusted odds ratio[aOR]: 0.96), surgery through one nare (aOR: 2.05), gross total resection(aOR: 0.21), and presence of CSF leak(aOR: 4.43) remained significantly associated with tumor recurrence. CONCLUSIONS We identified several predictors of tumor recurrence after pituitary adenoma resection. Notably, having gross total resection of the primary tumor had the most significant protective effect on tumor recurrence. Given the increased complication associated with repeat surgery, gross total resection should be attempted in all patients, if feasible. Patients with other predictors of tumor recurrence should be monitored more frequently to allow for early detection of recurrence to optimize treatment strategies.
O4‐10‐01: CHARACTERIZING CELL TYPE‐SPECIFIC EXPRESSION SIGNATURES IN BRAIN USING SINGLE CELL RNA SEQUENCING
Intracerebral haemorrhage (ICH) describes haemorrhage into the brain parenchyma that may result in a decline of the patient’s neurological function. ICH is a common cause of morbidity and mortality worldwide. Aggressive surgical treatment for ICH has remained controversial as clinical trials have failed to demonstrate substantial improvement in patient outcome and mortality. Recently, promising mechanical and pharmacological minimally invasive surgery (MIS) techniques for the treatment of ICH have been described. MIS was designed with the objective of reducing morbidity due to complications of surgical manipulation. Mechanical MIS includes the use of tubular retractors and small diameter instruments for ICH removal. Pharmacological methods consist of catheter placement inside the haematoma cavity for the passive drainage of the haematoma over the course of several days. One of the most favourable approaches for MIS is the use of natural corridors for reaching the lesion, such as the transsulcal parafascicular approach. This approach provides an anatomical dissection of the subjacent white matter tracts, causing the least amount of damage while evacuating the haematoma. A detailed description of the currently known MIS techniques and devices is presented in this review. Special attention is given to the transsulcal parafascicular approach, which has particular benefits to provide a less traumatic MIS with promising overall patient outcome.
SURG-04. SIMULTANEOUS CRANIOTOMIES FOR MULTIPLE BRAIN METASTASES
Abstract BACKGROUND: It is well known that for patients with solitary metastatic disease in the brain, aggressive surgical treatment can prolong survival. However, there is a paucity of literature focusing on simultaneous resection of multiple metastatic brain tumors. METHODS: We analyzed 13 patients and 26 tumors between 2005–2019 who had simultaneous resection of at least 2 metastatic brain tumors via either one or two craniotomies. We independently analyzed those patients with simultaneous resection of metastatic disease in both the supra- and infratentorial compartments. RESULTS: Overall, 26 tumors were resected in a simultaneous fashion. There were 7 females (53.8%) and 6 males (46.2%) total. 5/13 (38.5%) patients had previously known brain metastases in which all 5 had previous adjuvant radiation. All 13 patients had 2 metastatic lesions resected during one operation. Gross total resection rate reached 88.5% with a median post-operative stay of 3 days. Complications presented in only 3 out of 13 cases (grade 2 and 3 according to CTCAE). Primary sites of metastatic disease were lung, breast, skin and renal. 12/13 (92.3%) had two distinct craniotomies and 23/26 (88.5%) tumors had gross total resection of both lesions. There were 11 frontal (42.3%), 7 parietal (26.9%), 2 temporal (7.7%), 1 occipital (3.8%) and 5 cerebellar (19.2%) tumors. There were three patients with both supra- and intratentorial tumors with simultaneous resection. All three patients had two craniotomies and two separate incisions. 1 of the 3 had pre-operative SRS. Overall, average local progression since surgery to at least one resected tumor bed was 88.3 days. CONCLUSIONS: Our results suggest that patients with multiple metastatic brain lesions have comparable outcomes and similar rates of surgical risk to those with solitary brain lesions. In patients with simultaneous supra- and infratentorial brain metastatic disease and indications for decompression, safe resection is feasible.
MLTI-07. PREOPERATIVE VERSUS POSTOPERATIVE STEREOTACTIC RADIOSURGERY FOR LARGE BRAIN METASTASES: AN INTERNATIONAL META-ANALYSIS
Abstract PURPOSE: Preoperative stereotactic radiosurgery (SRS) for symptomatic brain metastases has arisen as a therapeutic option for patients with brain lesions, potentially reducing radionecrosis risk, leptomeningeal disease risk, as well as delays in systemic therapy after craniotomy. The purpose of our work is to analyze the current evidence regarding 1-year local control (LC) and RN rates in the preoperative and postoperative settings. METHODS AND MATERIALS: Population, Intervention, Control, Outcomes, Study Design/Preferred Reporting Items for Systematic Reviews and Meta-analyses and Meta-analysis of Observational Studies in Epidemiology guidelines were used to select articles in which patients had “large” brain metastases (>4 cm3 or >2 cm in diameter) solely treated with preoperative or postoperative SRS and 1-year LC and/or rates of RN reported. Radiosurgery was stratified by timing: preoperatively or postoperatively. Random effects meta-analyses using timing of SRS relative to surgery as covariates were conducted. Meta-regression and Wald-type tests were used to determine the effect of increasing tumor size on the summary estimate, where the null hypothesis was rejected for p < 0.05. RESULTS: Fifteen studies were included (of 314 screened), published between 2012 and 2018 with 854 brain metastases. Preoperative SRS was delivered in 229 lesions. The 1-year LC random effects estimate was 79.1% (95% confidence interval [CI]: 55.9–95.0%; I 2 = 80%) for preoperative SRS and 80.5% (95% CI: 66.3–91.5%; I 2 = 93%) for postoperative SRS (p=0.9). Radionecrosis incidence random effects estimate was 2.1% (95% CI: 0.1–8.6%; I 2 = 36%) for preoperative SRS and 6.3% (95% CI: 1.1–15.4%; I 2 = 90%) for postoperative SRS (p=0.52). CONCLUSIONS: Rates of 1-year LC and RN incidence are similar after preoperative SRS as compared to postoperative SRS for large brain metastases. Results from ongoing prospective clinical trials studying preoperative SRS are important to further investigate these two techniques.
BSCI-16. HEMODYNAMIC SHEAR STRESS SELECTS A SUBPOPULATION OF LUNG ADENOCARCINOMA CELLS WITH HIGHER METASTATIC CAPACITY
Abstract Patients with primary cancers often develop delayed brain metastases. One of the most common cancer types and sources of brain metastasis is lung cancer. For metastasis from lung cancer the 3-year survival is < 5%. Cancer cells in circulation are responsible for metastatic spread. The mechanical microenvironment plays an important role in cancer cells behavior. When cancer cells reach the bloodstream they are exposed to hemodynamic shear stress. It has been shown that most of the circulating tumor cells die once they reach the bloodstream, but the biology of the survival cells is poorly understood. We designed a microfluidics system that simulated the mechanical stress in the human circulating system such as turbulence, change in pressure (0.4-15dyn/cm2) and flow rate (1.06–106.1mm/s). Lung adenocarcinoma cells (A549) were put into circulation and collected after 72 hours. It was found that, 1.4±0.3% of the cells survived, and viability was evaluated by LDH and calcein. CD133, SOX2, and NANOG were downregulated and EMT genes were upregulated in the circulating cancer cells (CCCs) compared with cells in static-suspension or 2D. After re-seeding in 2D, CCCs overexpressed CD133. Female athymic nude rats (6-8weeks,n=16) received intracardiac injections of CCCs or 2D cells (GFP-LUC lentivirus traduced). Bioluminescence imaging was performed every week; the survival in of the CCCs group was lower than the 2D group. One-way ANOVA test was used to analyze survival and gene expression. Survival data was plotted on a Kaplan-Meier curve and compared using the Mantel-Cox logrank test, p=< 0.05. We have isolated a cellular subpopulation of lung adenocarcinoma with high resistance to hemodynamic shear stress that shows a higher metastatic capacity and genetic plasticity compared with cells growing in suspension or 2D. Targeting these cells would potentially allow us to develop personalized treatments to help to stop metastatic spread and improve actual therapeutical strategies.
AI-Assisted
In Situ
Detection of Human Glioma Infiltration Using a Novel Computational Method for Optical Coherence Tomography
Abstract Purpose: In glioma surgery, it is critical to maximize tumor resection without compromising adjacent noncancerous brain tissue. Optical coherence tomography (OCT) is a noninvasive, label-free, real-time, high-resolution imaging modality that has been explored for glioma infiltration detection. Here, we report a novel artificial intelligence (AI)-assisted method for automated, real-time, in situ detection of glioma infiltration at high spatial resolution. Experimental Design: Volumetric OCT datasets were intraoperatively obtained from resected brain tissue specimens of 21 patients with glioma tumors of different stages and labeled as either noncancerous or glioma-infiltrated on the basis of histopathology evaluation of the tissue specimens (gold standard). Labeled OCT images from 12 patients were used as the training dataset to develop the AI-assisted OCT-based method for automated detection of glioma-infiltrated brain tissue. Unlabeled OCT images from the other 9 patients were used as the validation dataset to quantify the method detection performance. Results: Our method achieved excellent levels of sensitivity (∼100%) and specificity (∼85%) for detecting glioma-infiltrated tissue with high spatial resolution (16 μm laterally) and processing speed (∼100,020 OCT A-lines/second). Conclusions: Previous methods for OCT-based detection of glioma-infiltrated brain tissue rely on estimating the tissue optical attenuation coefficient from the OCT signal, which requires sacrificing spatial resolution to increase signal quality, and performing systematic calibration procedures using tissue phantoms. By overcoming these major challenges, our AI-assisted method will enable implementing practical OCT-guided surgical tools for continuous, real-time, and accurate intraoperative detection of glioma-infiltrated brain tissue, facilitating maximal glioma resection and superior surgical outcomes for patients with glioma.