Citations

Abstract INTRODUCTION Neuroimaging dogma for glioblastoma asserts that hyperintensity on T1Gd MRI reveals the bulk of the tumor, while T2/FLAIR signal indicates edema. However, it is unclear whether this edema results from immune response or increased tumor cells. Further, one significant driver of the known sex differences in glioblastoma may be differences in immune response, due to the X-linkage of many immune genes. Based on this, we hypothesized that assumptions regarding tumor cellularity in T2/FLAIR images should be tailored to the biological sex of the patient. METHODS Using a retrospective cohort of 18 primary glioblastoma patients receiving multiple image-localized biopsies (82 total) and standard MRI, we assessed: distance of biopsy from T1Gd and T2 areas; a pathologist’s score of percent tumor cell density; and an imaging-based invasion metric, D/ρ. This metric is derived from the biomathematical Proliferation-Invasion model of glioma growth, which features two parameters, net growth rate (ρ) and net invasion rate (D). Their ratio D/ρ is related to degree of invasion, and is estimated from volumetric measurements of MRI abnormalities. Additionally, 25 patient-derived xenograft models implanted in females were grown until moribund, at which point brains were excised and stained for DAPI (to show all cells) and Lamin (to highlight tumor cells). Image processing of lamin-stained sections defines contours of intensity correlating with cell density. RESULTS Outside both the T1Gd and T2 region, male patient biopsies had higher tumor cell densities than females. Males also tended to have higher invasion metrics. Although each set derived from different patients, preclinical metrics of invasion were positively correlated with clinical invasion in females but negatively correlated in males. CONCLUSION Our preliminary finding that cell distribution patterns correlate with imaging metrics differently between the sexes supports the hypothesis that the degree of tumor cell density represented on certain MRI sequences may be sex-specific.

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.

Abstract There have been increasing efforts to standardize MRI scanning protocols for both routine and clinical trial imaging of glioma. The recent BTIP guidelines propose acquisition of T2-weighted images after gadiolinium (Gd) based contrast injection and before post-contrast 3D T1-weighted (T1W) images to control timing of images after contrast administration. While Gd-contrast shortens T1W signal and appears hyperintense on magnetic resonance imaging (MRI), Gd-contrast also shortens T2W signal, which could result in unintended alternations in T2W signal intensities. This has potential implications for model-based approaches for GBM diagnosis and the differential diagnosis of other tumor types (e.g., lymphoma) that rely on T2W signal characteristics. To our knowledge, no neuroimaging studies have formally evaluated the impact of Gd contrast on T2W imaging. We acquired multi-echo T2 sequences (TE=14, 28, 41, 55, 69 ms) both prior to and after the administration of Gd for 5 patients suspected of having a brain tumor. Quantitative T2 maps were created by fitting the signal decay to a signal exponential with the Levenburg-Marqurdt algorithm. Percent difference maps were calculated to compare the quantitative T2 changes between the pre- and post-Gd T2 maps. Additionally, we performed a Wilcoxon Rank-Sum test comparing T2 values within regions of interest (ROIs) representing the tumor and normal appearing white matter (NAWM). Significant differences between the T2 values in the tumor and NAWM ROIs were seen for 4 and 3 of the patients, respectively (all p-values < 0.01). Our initial data suggests that the administration of Gd contrast may affect T2 values in both the tumor and NAWM, which could impact quantitative image-based models and diagnoses in glioma. We are currently replicating these preliminary results in an expanded cohort.

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.

Abstract OBJECTIVES Dogma suggests that for brain tumors, regions of enhancement on T1-weighted gadolinium contrast enhanced (T1Gd) magnetic resonance imaging (MRI) correlate with intravenously delivered drug distribution as enhancement indicates a compromised blood-brain barrier (BBB). However, poor response to intravenous therapies highlights the importance of the diffuse disease beyond enhancing regions. This study investigated whether imaging features can provide an accurate prediction of drug distribution. METHODS Eight brain tumor patients (7 gliomas and 1 metastatic adenocarcinoma) were included in this Phase 0 trial. Presurgery T1-weighted, T1Gd, T2-weighted gadolinium contrast enhanced (T2Gd), and T2-weighted Fluid Attenuated Inversion Recovery (T2FLAIR) MRIs were acquired. All images underwent bias correction using the N4 algorithm, standardization of intensities, and registration. Prior to incision, patients received both an antibiotic cefazolin (6% BBB penetrance) and levetiracetam (80% BBB penetrance), an anti-seizure drug. Subsequently, multiple blood samples and image-guided biopsies were taken and analyzed for drug concentration using liquid chromatography mass spectrometry. Biopsy drug levels are reported as Brain-Plasma Ratio (BPR), the ratio of biopsy concentration relative to plasma concentration. Mean image intensity was extracted from an 8x8 mm window surrounding each biopsy location. Regression analysis was performed to determine which combination of image types were linearly predictive of BPR for both drugs. Correlations were also analyzed according to the biopsy location radiographic appearance. RESULTS Regression analysis revealed that T2Gd intensity was linearly predictive of cefazolin BPR and FLAIR intensity was linearly predictive of levetiracetam BPR (p=0.009 and 0.041, respectively). Grouping samples according the the radiographic appearance revealed that levetiracetam BPR had a similar pattern of values to that of FLAIR intensities and cefazolin BPR had a similar pattern to T2, further supporting the regression analysis results. CONCLUSIONS Local concentrations of drug may be related to T2-weighted signals (T2Gd and T2FLAIR) rather than the gadolinium distribution on T1Gd images.

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.

Objective: We sought to describe contemporary presentation, treatment, and outcomes of patients presenting with acute (A), perforated (P), and gangrenous (G) appendicitis in the United States. Summary Background Data: Recent European trials have reported that medical (antibiotics only) treatment of acute appendicitis is an acceptable alternative to surgical appendectomy. However, the type of operation (open appendectomy) and average duration of stay are not consistent with current American practice and therefore their conclusions do not apply to modern American surgeons. Methods: This multicenter prospective observational study enrolled adults with appendicitis from January 2017 to June 2018. Descriptive statistics were performed. P and G were combined into a “complicated” outcome variable and risk factors were assessed using multivariable logistic regression. Results: A total 3597 subjects were enrolled across 28 sites: median age was 37 (27–52) years, 1918 (53%) were male, 90% underwent computed tomography (CT) imaging, 91% were initially treated by appendectomy (98% laparoscopic), and median hospital stay was 1 (1–2) day. The 30-day rates of Emergency Department (ED) visit and readmission were 10% and 6%. Of 219 initially treated with antibiotics, 35 (16%) required appendectomy during index hospitalization and 12 (5%) underwent appendectomy within 30 days, for a cumulative failure rate of 21%. Overall, 2403 (77%) patients had A, whereas 487 (16%) and 218 (7%) patients had P and G, respectively. On regression analysis, age, symptoms >48 hours, temperature, WBC, Alvarado score, and appendicolith were predictive of “complicated” appendicitis, whereas co-morbidities, smoking, and ED triage to appendectomy >6 hours or >12 hours were not. Conclusion: In the United States, the majority of patients presenting with appendicitis receive CT imaging, undergo laparoscopic appendectomy, and stay in the hospital for 1 day. One in five patients selected for initial non-operative management required appendectomy within 30 days. In-hospital delay to appendectomy is not a risk factor for “complicated” appendicitis.

OBJECTIVEScoliosis is frequently a presenting sign of Chiari malformation type I (CM-I) with syrinx. The authors’ goal was to define scoliosis in this population and describe how radiological characteristics of CM-I and syrinx relate to the presence and severity of scoliosis.METHODSA large multicenter retrospective and prospective registry of pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for clinical and radiological characteristics of CM-I, syrinx, and scoliosis (coronal curve ≥ 10°).RESULTSBased on available imaging of patients with CM-I and syrinx, 260 of 825 patients (31%) had a clear diagnosis of scoliosis based on radiographs or coronal MRI. Forty-nine patients (5.9%) did not have scoliosis, and in 516 (63%) patients, a clear determination of the presence or absence of scoliosis could not be made. Comparison of patients with and those without a definite scoliosis diagnosis indicated that scoliosis was associated with wider syrinxes (8.7 vs 6.3 mm, OR 1.25, p < 0.001), longer syrinxes (10.3 vs 6.2 levels, OR 1.18, p < 0.001), syrinxes with their rostral extent located in the cervical spine (94% vs 80%, OR 3.91, p = 0.001), and holocord syrinxes (50% vs 16%, OR 5.61, p < 0.001). Multivariable regression analysis revealed syrinx length and the presence of holocord syrinx to be independent predictors of scoliosis in this patient cohort. Scoliosis was not associated with sex, age at CM-I diagnosis, tonsil position, pB–C2 distance (measured perpendicular distance from the ventral dura to a line drawn from the basion to the posterior-inferior aspect of C2), clivoaxial angle, or frontal-occipital horn ratio. Average curve magnitude was 29.9°, and 37.7% of patients had a left thoracic curve. Older age at CM-I or syrinx diagnosis (p < 0.0001) was associated with greater curve magnitude whereas there was no association between syrinx dimensions and curve magnitude.CONCLUSIONSSyrinx characteristics, but not tonsil position, were related to the presence of scoliosis in patients with CM-I, and there was an independent association of syrinx length and holocord syrinx with scoliosis. Further study is needed to evaluate the nature of the relationship between syrinx and scoliosis in patients with CM-I.

Key Points The ClinGen MM-VCEP has specified RUNX1-specific curation rules to address gene function, gene-specific domains, and phenotypic criteria. RUNX1-specific criteria resulted in a reduction in CONF and VUS variants by 33%, emphasizing the need for expert variant curation.