Sex-specific Differences in IDH1-Wildtype Glioblastoma patients in the ReSPOND Consortium.

BACKGROUND: Understanding sex-based differences in glioblastoma patients is necessary for accurate personalized treatment planning to improve patient outcomes. PURPOSE: To investigate sex-specific differences in molecular, clinical and radiological tumor parameters, as well as survival outcomes in glioblastoma, isocitrate dehydrogenase-1 wildtype (IDH1-WT), grade 4 patients. METHODS: Retrospective data of 1832 glioblastoma, IDH1-WT patients with comprehensive information on tumor parameters was acquired from the Radiomics Signatures for Precision Oncology in Glioblastoma (ReSPOND) consortium. Data imputation was performed for missing values. Sex-based differences in tumor parameters, such as, age, molecular parameters, pre-operative KPS score, tumor volumes, epicenter and laterality were assessed through non-parametric tests. Spatial atlases were generated using pre-operative MRI maps to visualize tumor characteristics. Survival time analysis was performed through log-rank tests and Cox proportional hazard analyses. RESULTS: GBM was diagnosed at a median age of 64 years in females compared to 61.9 years in males (FDR = 0.003). Males had a higher Karnofsky Performance Score (above 80) as compared to females (60.4% females Vs 69.7% males, FDR = 0.044). Females had lower tumor volumes in enhancing (16.7 cm3 Vs. 20.6 cm3 in males, FDR = 0.001), necrotic core (6.18 cm3 Vs. 7.76 cm3 in males, FDR = 0.001) and edema regions (46.9 cm3 Vs. 59.2 cm3 in males, FDR = 0.0001). Right temporal region was the most common tumor epicenter in the overall population. Right as well as left temporal lobes were more frequently involved in males. There were no significant differences in survival outcomes and mortality ratios. Higher age, unmethylated O6-methylguanine-DNAmethyltransferase (MGMT) promoter and undergoing subtotal resection increased the mortality risk in both males and females. CONCLUSIONS: Our study demonstrates significant sex-based differences in clinical and radiological tumor parameters of glioblastoma, IDH1-WT, grade 4 patients. Sex is not an independent prognostic factor for survival outcomes and the tumor parameters influencing patient outcomes are identical for males and females. ABBREVIATIONS: IDH1-WT = isocitrate dehydrogenase-1 wildtype; MGMTp = O6-methylguanine-DNA-methyltransferase promoter; KPS = Karnofsky performance score; EOR = extent of resection; WHO = world health organization; FDR = false discovery rate.

Association of partial T2-FLAIR mismatch sign and isocitrate dehydrogenase mutation in WHO grade 4 gliomas: results from the ReSPOND consortium.

PURPOSE: While the T2-FLAIR mismatch sign is highly specific for isocitrate dehydrogenase (IDH)-mutant, 1p/19q-noncodeleted astrocytomas among lower-grade gliomas, its utility in WHO grade 4 gliomas is not well-studied. We derived the partial T2-FLAIR mismatch sign as an imaging biomarker for IDH mutation in WHO grade 4 gliomas. METHODS: Preoperative MRI scans of adult WHO grade 4 glioma patients (n = 2165) from the multi-institutional ReSPOND (Radiomics Signatures for PrecisiON Diagnostics) consortium were analyzed. Diagnostic performance of the partial T2-FLAIR mismatch sign was evaluated. Subset analyses were performed to assess associations of imaging markers with overall survival (OS). RESULTS: One hundred twenty-one (5.6%) of 2165 grade 4 gliomas were IDH-mutant. Partial T2-FLAIR mismatch was present in 40 (1.8%) cases, 32 of which were IDH-mutant, yielding 26.4% sensitivity, 99.6% specificity, 80.0% positive predictive value, and 95.8% negative predictive value. Multivariate logistic regression demonstrated IDH mutation was significantly associated with partial T2-FLAIR mismatch (odds ratio [OR] 5.715, 95% CI [1.896, 17.221], p = 0.002), younger age (OR 0.911 [0.895, 0.927], p < 0.001), tumor centered in frontal lobe (OR 3.842, [2.361, 6.251], p < 0.001), absence of multicentricity (OR 0.173, [0.049, 0.612], p = 0.007), and presence of cystic (OR 6.596, [3.023, 14.391], p < 0.001) or non-enhancing solid components (OR 6.069, [3.371, 10.928], p < 0.001). Multivariate Cox analysis demonstrated cystic components (p = 0.024) and non-enhancing solid components (p = 0.003) were associated with longer OS, while older age (p < 0.001), frontal lobe center (p = 0.008), multifocality (p < 0.001), and multicentricity (p < 0.001) were associated with shorter OS. CONCLUSION: Partial T2-FLAIR mismatch sign is highly specific for IDH mutation in WHO grade 4 gliomas.

Persistent Peri-Ablation Blood-Brain Barrier Opening After Laser Interstitial Thermal Therapy for Brain Tumors.

Purpose Laser interstitial thermal therapy (LITT) is a minimally invasive, image-guided, cytoreductive procedure to treat recurrent glioblastoma. This study implemented dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) methods and employed a model selection paradigm to localize and quantify post-LITT blood-brain barrier (BBB) permeability in the ablation vicinity. Serum levels of neuron-specific enolase (NSE), a peripheral marker of increased BBB permeability, were measured. Methods Seventeen patients were enrolled in the study. Using an enzyme-linked immunosorbent assay, serum NSE was measured preoperatively, 24 hours postoperatively, and at two, eight, 12, and 16 weeks postoperatively, depending on postoperative adjuvant treatment. Of the 17 patients, four had longitudinal DCE-MRI data available, from which blood-to-brain forward volumetric transfer constant (Ktrans) data were assessed. Imaging was performed preoperatively, 24 hours postoperatively, and between two and eight weeks postoperatively. Results Serum NSE increased at 24 hours following ablation (p=0.04), peaked at two weeks, and returned to baseline by eight weeks postoperatively. Ktrans was found to be elevated in the peri-ablation periphery 24 hours after the procedure. This increase persisted for two weeks. Conclusion Following the LITT procedure, serum NSE levels and peri-ablation Ktrans estimated from DCE-MRI demonstrated increases during the first two weeks after ablation, suggesting transiently increased BBB permeability.

The impact of initial tumor microenvironment on imaging phenotype.

Models of human cancer, to be useful, must replicate human disease with high fidelity. Our focus in this study is rat xenograft brain tumors as a model of human embedded cerebral tumors. A distinguishing signature of such tumors in humans, that of contrast-enhancement on imaging, is often not present when the human cells grow in rodents, despite the xenografts having nearly identical DNA signatures to the original tumor specimen. Although contrast enhancement was uniformly evident in all the human tumors from which the xenografts' cells were derived, we show that long-term contrast enhancement in the model tumors may be determined conditionally by the tumor microenvironment at the time of cell implantation. We demonstrate this phenomenon in one of two patient-derived orthotopic xenograft (PDOX) models using cancer stem-like cell (CSC)-enriched neurospheres from human tumor resection specimens, transplanted to groups of immune-compromised rats in the presence or absence of a collagen/fibrin scaffolding matrix, Matrigel. The rats were imaged by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and their brains were examined by histopathology. Targeted proteomics of the PDOX tumor specimens grown from CSC implanted with and without Matrigel showed that while the levels of the majority of proteins and post-translational modifications were comparable between contrast-enhancing and non-enhancing tumors, phosphorylation of Fox038 showed a differential expression. The results suggest key proteins determine contrast enhancement and suggest a path toward the development of better animal models of human glioma. Future work is needed to elucidate fully the molecular determinants of contrast-enhancement.

Providing Epidemiological Data in Lumbar Spine Imaging Reports Did Not Affect Subsequent Utilization of Spine Procedures: Secondary Outcomes from a Stepped-Wedge Randomized Controlled Trial.

OBJECTIVE: To evaluate the effect of inserting epidemiological information into lumbar spine imaging reports on subsequent nonsurgical and surgical procedures involving the thoracolumbosacral spine and sacroiliac joints. DESIGN: Analysis of secondary outcomes from the Lumbar Imaging with Reporting of Epidemiology (LIRE) pragmatic stepped-wedge randomized trial. SETTING: Primary care clinics within four integrated health care systems in the United States. SUBJECTS: 238,886 patients ≥18 years of age who received lumbar diagnostic imaging between 2013 and 2016. METHODS: Clinics were randomized to receive text containing age- and modality-specific epidemiological benchmarks indicating the prevalence of common spine imaging findings in people without low back pain, inserted into lumbar spine imaging reports (the "LIRE intervention"). The study outcomes were receiving 1) any nonsurgical lumbosacral or sacroiliac spine procedure (lumbosacral epidural steroid injection, facet joint injection, or facet joint radiofrequency ablation; or sacroiliac joint injection) or 2) any surgical procedure involving the lumbar, sacral, or thoracic spine (decompression surgery or spinal fusion or other spine surgery). RESULTS: The LIRE intervention was not significantly associated with subsequent utilization of nonsurgical lumbosacral or sacroiliac spine procedures (odds ratio [OR] = 1.01, 95% confidence interval [CI] 0.93-1.09; P = 0.79) or any surgical procedure (OR = 0.99, 95 CI 0.91-1.07; P = 0.74) involving the lumbar, sacral, or thoracic spine. The intervention was also not significantly associated with any individual spine procedure. CONCLUSIONS: Inserting epidemiological text into spine imaging reports had no effect on nonsurgical or surgical procedure utilization among patients receiving lumbar diagnostic imaging.

Effects of Including Epidemiologic Data in Lumbar Spine Imaging Reports on Prescribing Non-Opioid Medications for Pain.

BACKGROUND: Information on the prevalence of common imaging findings among patients without back pain in spine imaging reports might affect pain medication prescribing for patients with back pain. Prior research on inserting this text suggested a small reduction in opioid prescribing. OBJECTIVE: To evaluate the effect of epidemiologic information in spine imaging reports on non-opioid pain medication prescribing for primary care patients with back pain. DESIGN: Post hoc analysis of the Lumbar Imaging with Reporting of Epidemiology cluster-randomized trial. PARTICIPANTS: A total of 170,680 patients aged ≥ 18 years from four healthcare systems who received thoracolumbar, lumbar, or lumbosacral spine imaging from 2013 to 2016 and had not received a prescription for non-opioid pain medication in the preceding 120 days. INTERVENTION: Text of age- and modality-specific epidemiologic benchmarks indicating the prevalence of common findings in people without back pain inserted into thoracolumbar, lumbar, or lumbosacral spine imaging reports at intervention clinics. MAIN MEASURES: Primary outcomes: any non-opioid prescription within 90 days after index imaging, overall, and by sub-class (skeletal muscle relaxants, NSAIDs, gabapentinoids, tricyclic antidepressants, benzodiazepines, duloxetine). SECONDARY OUTCOMES: count of non-opioid prescriptions within 90 days, overall, and by sub-class. KEY RESULTS: The intervention was not associated with the likelihood of patients receiving at least one prescription for new non-opioid pain-related medications, overall (adjusted OR, 1.02; 95% CI, 0.97-1.08) or by sub-class. The intervention was not associated with the number of prescriptions for any non-opioid medication (adjusted incidence rate ratio [IRR], 1.02; 95% CI, 0.99-1.04). However, the intervention was associated with more new prescriptions for NSAIDs (IRR, 1.12) and tricyclic antidepressants (IRR, 1.11). CONCLUSIONS: Inserting epidemiologic text in spine imaging reports had no effect on whether new non-opioid pain-related medications were prescribed but was associated with the number of new prescriptions for certain non-opioid sub-classes. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02015455.

Impact of the COVID-19 pandemic on radiology physician work RVUs at a large subspecialized radiology practice.

PURPOSE: As the COVID-19 pandemic continues, efforts by radiology departments to protect patients and healthcare workers and mitigate disease spread have reduced imaging volumes. This study aims to quantify the pandemic's impact on physician productivity across radiology practice areas as measured by physician work Relative Value Units (wRVUs). MATERIALS AND METHODS: All signed diagnostic and procedural radiology reports were curated from January 1st to July 1st of 2019 and 2020. Physician work RVUs were assigned to each study type based on the Medicare Physician Fee Schedule. Utilizing divisional assignments, radiologist schedules were mapped to each report to generate a sum of wRVUs credited to that division for each week. Differential impact on divisions were calculated relative to a matched timeframe in 2019 and a same length pre-pandemic time period in 2020. RESULTS: All practice areas saw a substantial decrease in wRVUs from the 2020 pre- to intra-pandemic time period with a mean decrease of 51.5% (range 15.4%-76.9%). The largest declines were in Breast imaging, Musculoskeletal, and Neuroradiology, which had decreases of 76.9%, 75.3%, and 67.5%, respectively. The modalities with the greatest percentage decrease were mammography, MRI, and non-PET nuclear medicine. CONCLUSION: All radiology practice areas and modalities experienced a substantial decrease in wRVUs. The greatest decline was in Breast imaging, Neuroradiology, and Musculoskeletal radiology. Understanding the differential impact of the pandemic on practice areas will help radiology departments prepare for the potential depth and duration of the pandemic by better understanding staffing needs and the financial effects.

Imaging Findings in Non-Neoplastic Sinonasal Disease: Review of Imaging Features With Endoscopic Correlates.

Non-neoplastic sinonasal disease is common and imaging often plays an important role in establishing the proper diagnosis, guiding clinical management, and evaluating for complications. Both computed tomography and magnetic resonance imaging are commonly employed in the imaging evaluation and it is important to understand the imaging characteristics of the unique types of pathology affecting the sinonasal cavities. This article reviews a variety of infectious, inflammatory, and other non-neoplastic sinonasal pathologies, highlighting imaging features that aid in their differentiation.

COVID-19 and Radiology Resident Imaging Volumes-Differential Impact by Resident Training Year and Imaging Modality.

RATIONALE AND OBJECTIVES: The COVID-19 pandemic has greatly impacted radiology departments across the country. The pandemic has also disrupted resident education, both due to departmental social distancing efforts and reduced imaging volumes. The purpose of this study was to assess the differential impact the pandemic had on radiology resident imaging volumes by training year and imaging modality. MATERIALS AND METHODS: All signed radiology resident reports were curated during defined prepandemic and intrapandemic time periods. Imaging case volumes were analyzed on a mean per resident basis to quantify absolute and percent change by training level. Change in total volume by imaging modality was also assessed. The number of resident workdays assigned outside the normal reading room was also calculated. RESULTS: Overall percent decline in resident imaging interpretation volume from the prepandemic to intrapandemic time period was 62.8%. R1s and R2s had the greatest decline at 87.3% and 64.3%, respectively. Mammography, MRI and nuclear medicine had the greatest decline in resident interpretation volume at 92.0%, 73.2%, and 73.0%, respectively. During the intrapandemic time period, a total of 478 resident days (mean of 14.5 days per resident) were reassigned outside of the radiology reading room. CONCLUSION: The COVID-19 pandemic caused a marked decrease in radiology resident imaging interpretation volume and has had a tremendous impact on resident education. The decrease in case interpretation, as well as in-person teaching has profound implications for resident education. Knowledge of this differential decrease by training level will help residency programs plan for the future.

Sarcopenia Predicts Overall Survival in Patients with Lung, Breast, Prostate, or Myeloma Spine Metastases Undergoing Stereotactic Body Radiation Therapy (SBRT), Independent of Histology.

BACKGROUND: Predicting survival of patients with spinal metastases would help stratify treatments from aggressive to palliation. OBJECTIVE: To evaluate whether sarcopenia predicts survival in patients with lung, breast, prostate, or multiple myeloma spinal metastases. METHODS: Psoas muscle measurements in patients with spinal metastasis were taken from computed tomography scans at 2 time points: at first episode of stereotactic body radiation therapy (SBRT) and from the most recent scan available. Overall survival and hazard ratios were calculated with multivariate cox proportional hazards regression analyses. RESULTS: In 417 patients with spinal metastases, 40% had lung cancer, 27% breast, 21% prostate, and 11% myeloma. Overall survival was not associated with age, sex, ethnicity, levels treated, or SBRT volume. Multivariate analysis showed patients in the lowest psoas tertile had shorter survival (222 d, 95% CI = 185-323 d) as compared to the largest tertile (579 d, 95% CI = 405-815 d), (HR1.54, P = .005). Median psoas size as a cutoff value was also strongly predictive for survival (HR1.48, P = .002). Survival was independent of tumor histology. The psoas/vertebral body ratio was also successful in predicting overall survival independent of tumor histology and gender (HR1.52, P < .01). Kaplan-Meier survival curves visually represent survival (P = .0005). CONCLUSION: In patients with spine metastases, psoas muscle size as a hallmark of frailty/sarcopenia is an objective, simple, and effective way to identify patients who are at risk for shorter survival, regardless of tumor histology. This information can be used to help with surgical decision making in patients with advanced cancer, as patients with small psoas sizes are at higher risk of death.

Intraclass Correlations of Measured Magnetic Resonance Imaging Volumes of Laser Interstitial Thermal Therapy-Treated High-Grade Gliomas.

BACKGROUND AND OBJECTIVES: Laser interstitial thermal therapy (LITT) is a minimally invasive therapeutic option for the treatment of brain tumors. Previous studies have quantitatively followed the ablated volumes of high-grade gliomas. Reported treatment volumes range from 28% to 100%, with no reported interobserver analysis. Because these volumes are subjectively measured, it is necessary to establish concordance between clinicians. STUDY DESIGN/MATERIALS AND METHODS: Utilizing Brainlab tumor analysis software (Brainlab, Munich, Germany), five physician users traced out tumor volumes slice-by-slice on 10 treated tumors in eight patients. The participants were briefed with specific instructions and a demonstration on how to trace the enhancing borders of the tumor slice-by-slice. Volumes automatically calculated by the Brainlab software included preoperative, intraoperative ablation and postoperative enhancing volumes. Data regarding size, cystic appearance, pathology, previous surgery, and demographics were included. RESULTS: The intraclass correlation coefficient (ICC) for preoperative, intraoperative, and postoperative volumes was 0.92 (95% confidence interval, [CI] 0.81-0.97), 0.90 (0.77-0.96), and 0.89 (0.74-0.96), respectively. The overall ICC was 0.72 (0.50-0.87). ICC comparisons were also made for each pair of readers (neuroradiologist, neuro-oncologist, senior neurosurgery resident, neurosurgery junior resident) which resulted in pretreatment ICC scores of 0.97, 0.91, 0.66, 0.94; intratreatment scores of 0.97, 0.78, 0.90, 0.96; and posttreatment scores of 0.96, 0.81, 0.89, and 0.87. A Bland-Altman plot was also used to assess the differences in volumes. CONCLUSIONS: The ICC gives a composite of the consistency of measurements made by multiple observers measuring the same quantity. The overall ICC of 0.72 means there is good correlation between observers in our study between measured volumes. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Imaging and diagnostic advances for intracranial meningiomas.

The archetypal imaging characteristics of meningiomas are among the most stereotypic of all central nervous system (CNS) tumors. In the era of plain film and ventriculography, imaging was only performed if a mass was suspected, and their results were more suggestive than definitive. Following more than a century of technological development, we can now rely on imaging to non-invasively diagnose meningioma with great confidence and precisely delineate the locations of these tumors relative to their surrounding structures to inform treatment planning. Asymptomatic meningiomas may be identified and their growth monitored over time; moreover, imaging routinely serves as an essential tool to survey tumor burden at various stages during the course of treatment, thereby providing guidance on their effectiveness or the need for further intervention. Modern radiological techniques are expanding the power of imaging from tumor detection and monitoring to include extraction of biologic information from advanced analysis of radiological parameters. These contemporary approaches have led to promising attempts to predict tumor grade and, in turn, contribute prognostic data. In this supplement article, we review important current and future aspects of imaging in the diagnosis and management of meningioma, including conventional and advanced imaging techniques using CT, MRI, and nuclear medicine.

Sellar Atypical Teratoid/Rhabdoid Tumor Presenting with Subarachnoid and Intraventricular Hemorrhage.

BACKGROUND: Atypical teratoid/rhabdoid tumors (ATRT) are uncommon malignancies of the central nervous system and are often difficult to distinguish radiographically and pathologically from other common tumors. We present the first case of sellar ATRT presenting with subarachnoid hemorrhage (SAH) and intraventricular hemorrhage (IVH). CASE DESCRIPTION: A 62-year-old woman, who had presented with symptoms of headache, diabetes insipidus, hypothyroidism, and seizures, was found to have a sellar tumor with hemorrhagic transformation. Surgical resection was performed. The pathological examination findings were consistent with ATRT. Despite early surgical intervention, she later died before starting craniospinal radiotherapy and chemotherapy. CONCLUSION: To the best of our knowledge, although known to present with intratumoral hemorrhage, to date, no cases of sellar ATRT have presented with SAH or IVH have been reported. Considering our finding that ATRT can present with SAH and IVH, establishing the correct diagnosis using radiographic imaging, gender, pathological findings, and molecular markers is paramount for speedy treatment and management.

Multi-faceted computational assessment of risk and progression in oligodendroglioma implicates NOTCH and PI3K pathways.

Oligodendrogliomas are diffusely infiltrative gliomas defined by IDH-mutation and co-deletion of 1p/19q. They have highly variable clinical courses, with survivals ranging from 6 months to over 20 years, but little is known regarding the pathways involved with their progression or optimal markers for stratifying risk. We utilized machine-learning approaches with genomic data from The Cancer Genome Atlas to objectively identify molecular factors associated with clinical outcomes of oligodendroglioma and extended these findings to study signaling pathways implicated in oncogenesis and clinical endpoints associated with glioma progression. Our multi-faceted computational approach uncovered key genetic alterations associated with disease progression and shorter survival in oligodendroglioma and specifically identified Notch pathway inactivation and PI3K pathway activation as the most strongly associated with MRI and pathology findings of advanced disease and poor clinical outcome. Our findings that Notch pathway inactivation and PI3K pathway activation are associated with advanced disease and survival risk will pave the way for clinically relevant markers of disease progression and therapeutic targets to improve clinical outcomes. Furthermore, our approach demonstrates the strength of machine learning and computational methods for identifying genetic events critical to disease progression in the era of big data and precision medicine.

Morphometrics predicts overall survival in patients with multiple myeloma spine metastasis: A retrospective cohort study.

Background: Treatment strategies for spinal metastases for myeloma range from conservative measures (radiation and chemotherapy) to invasive (surgical). Identifying better predictors of overall survival (OS) would help in surgical decision making. Analytic morphometrics has been shown to predict survival in oncologic patients, and our study evaluates whether morphometrics is predictive of survival in patients with multiple myeloma (MM) spinal metastases. Methods: For this observational retrospective cohort study, we identified 46 patients with MM spinal metastases who had undergone stereotactic body radiation therapy. OS was the primary outcome measure. Morphometric analysis of the psoas muscle was performed using computed tomography scans of the lumbar spine. Results: OS was statistically correlated with age (P = 0.025), tumor burden (P = 0.023), and number of levels radiated (P = 0.029), but not with gender. Patients in the lowest tertile of average psoas size had significantly shorter survival compared to the highest tertile, hazard ratio (HZ) 6.87 (95% CI = 1.65-28.5, P = 0.008). When calculating the psoas size to vertebral body ratio and correlating this measure to OS, the lowest tertile again had significantly shorter OS compared to the highest tertile, HZ 6.87 (95% CI = 1.57-29.89, P = 0.010); the middle tertile also showed significantly shorter OS compared to the highest tertile, HZ 5.07 (95% CI = 1.34-19.10, P = 0.016). Kaplan-Meier survival curves were used to visually illustrate the differences in survival between different tertiles (Log-rank test P = 0.006). Conclusions: Morphometric analysis successfully predicts long-term survival in patients with MM. More research is needed to validate these results and to see if these methodologies can be applied to other cancer histologies.

Application of morphometrics as a predictor for survival in female patients with breast cancer spinal metastasis: a retrospective cohort study.

BACKGROUND CONTEXT: The current standard of care for prediction of survival of cancer staging is based on TNM staging. However, for patients with spinal metastasis, who all have identical stage IV disease, identifying accurate prognostic markers of survival would allow better treatment stratification between more aggressive treatment strategies or palliation. Analytical morphometrics enables physicians to quantify patient frailty by measuring lean muscle mass. Morphometrics also predicts survival in patients with lung cancer metastases to the spine. PURPOSE: Our study evaluates whether morphometrics is predictive of survival in patients with breast cancer spinal metastasis. DESIGN: This is an observational retrospective cohort study. PATIENT SAMPLE: This study includes female patients with breast cancer spinal metastases and patients who have undergone stereotactic body radiation therapy. OUTCOME MEASURES: Overall survival was the primary outcome measure. METHODS: Morphometric measurements of the psoas muscle were taken using computed tomography scans of the lumbar spine. We then stratified patients into tertiles based on the psoas muscle area. RESULTS: We identified 118 patients, with a median survival of 104 days (95% confidence interval [CI]=73-157 days). Overall survival was not associated with age, chemotherapy, or number of levels radiated. Patients in the lowest tertile of psoas size had significantly shorter survival compared with the highest tertile (68 days versus 148 days, hazard ratio 1.76 [95% CI=1.08-2.89], p=.024). The shorter survival was also true for the lowest tertile versus the middle tertile (68 days versus 167 days, hazard ratio 1.95 [95% CI=1.19-3.19], p=.007). Kaplan-Meier survival curves were used to visually illustrate the differences in survival between different tertiles. CONCLUSIONS: Morphometric analysis of the psoas muscle size in patients with breast cancer metastases to the spine was effective in identifying patients at risk of shorter survival. Further research is needed to validate these results, as well as to see if these methodologies can be applied to other cancer histologies.

Application of Morphometrics as a Predictor for Survival in Patients with Prostate Cancer Metastasis to the Spine.

BACKGROUND: Surgery for spinal metastases can improve survival but has high morbidity that can potentially diminish benefits. New objective methods of predicting overall survival would be beneficial for surgical decision making. Morphometrics quantifies patient frailty and has been successfully used to predict overall survival in patients with lung cancer spinal metastases. This study evaluated whether morphometrics can predict survival in patients with prostate cancer spinal metastases. METHODS: Using a retrospective registry of patients with spinal metastases who underwent stereotactic body radiation therapy, we identified patients with primary prostate cancer. Morphometric measurements of the psoas muscle were taken from most recent lumbar spine computed tomography. Patients were stratified into lowest, middle, and highest tertiles based on psoas muscle area. Primary outcome measure was overall survival from the date of computed tomography scan. RESULTS: We identified 92 patients. Median survival for all patients was 124 days (95% confidence interval, 98-197 days). Patients in the smallest third for average psoas size had significantly shorter survival compared with patients in the largest third: 117 days versus 302 days (hazard ratio 2.42; 95% confidence interval, 1.32-4.43; P = 0.004). Patients in the middle third for average psoas size also had shorter survival compared with patients in the largest third: 113 days versus 302 days (hazard ratio 2.31; 95% confidence interval, 1.25-4.25; P = 0.007). CONCLUSIONS: In patients with prostate cancer spinal metastases, morphometric analysis of psoas muscle size can identify patients at risk for shorter survival. This technique can aid in surgical decision making by weighing expected survival and fitness versus potential morbidity of intervention.

The reliability of identifying the Omega sign using axial T2-weighted magnetic resonance imaging.

Preoperative identification of the eloquent brain is important for neurosurgical planning. One common method of finding the motor cortex is by localizing "the Omega sign." No studies have tested the reliability of imaging to identify the Omega sign. We identified 40 recent and consecutive patients who had undergone preoperative functional magnetic resonance imaging for identification of the hand motor area prior to tumor resection. We recruited 11 neurosurgical residents of various levels of training and one board-certified neurosurgeon to identify the hand motor cortex Omega. Testees were given axial images of T2-weighted MRI and placed marks where they expected to find the Omega. Two board-certified radiologists graded and quantified the localization attempts. Inter-rater reliability was assessed using the kappa statistic, and Rao-Scott chi-square tests were used to examine the relationship between clinical factors and testees' experience with correct identification of the Omega sign. The overall correct identification rate was 69.9% (95% CI = 63.4-75.7), ranging from 36.6% to 92.7% among all raters for the tumor side and from 46.2% to 97.4% for the non-tumor side. Anatomic distortion greatly affected correct identification ( p < 0.005). Senior residents had a significantly higher rate of identification of the Omega than junior residents ( p < 0.001). Overall, inter-rater reliability for the Omega sign is poor, with a Fleiss kappa of 0.23. We concluded that correct identification of the Omega sign is affected by tumor distortion and experience but overall is not reliable. This underscores the limitations of anatomic landmarks and the importance of utilizing multiple scanning planes and preoperative fMRI for appropriate localization.

Cord Topographical Anatomy and its Role in Evaluating Intramedullary Lesions.

Intramedullary spinal lesions present a wide differential diagnosis including infectious, inflammatory, traumatic, ischemic, benign, or malignant neoplastic etiologies. Using knowledge of anatomy and physiology within the spinal cord, many similar appearing entities can be parsed into a prioritized differential. The purpose of this article is to review anatomy and pathophysiology of the spinal cord, with subsequent discussion of how this knowledge can be used to differentiate several similar appearing intramedullary pathologic processes. Discussion includes the pathophysiology, imaging findings, and clinical pearls of several intramural lesions including infarct, demyelinating lesions, traumatic injury, neoplasm, vascular malformation, and metabolic processes such as subacute combined degeneration.