Baseline Computed Tomography Scans Research Articles

869 Early Signs of Elevated Intracranial Pressure (ICP) on Computed Tomography Correlate With Measured ICP in the Intensive Care Unit and Six-month Outcome Following Moderate to Severe TBI

INTRODUCTION: Identifying patients at risk for increased intracranial pressure (ICP) followingTBI via baseline computed tomography (CT) has not previously been validated in a prospective dataset. METHODS: Data were obtained from the Progesterone for Traumatic Brain Injury, Experimental Clinical Treatment (ProTECTIII) multicenter clinical trial. Baseline CT scans for 881 participants were individually reviewed by a blinded central neuroradiologist. Five signs of elevated ICP were measured (sulcal obliteration, lateral ventricle compression, 3rd ventricle compression, midline shift, and herniation). Associations between signs of increased ICP and outcomes (6-month functional outcome and mortality) were assessed. RESULTS: Sulcal obliteration (p = 0.029) and third ventricular compression (p = 0.039) were associated with elevated ICP. Univariate regression analyses indicated that increasing combinations of the five defined signs of elevated ICP were associated with mortality, poor functional outcome, and time to death. There was also an increased likelihood of mortality if patients required craniotomy (OR = 4.318, 95% Confidence Interval [1.330-16.030]) or hemicraniectomy (OR = 2.993 [1.109-8.482]). On multivariate regression analyses, hemorrhage location was associated with mortality (posterior fossa, OR = 3.208 [1.120-9.188] and basal ganglia, OR = 3.079 [1.178-8.077]). Volume of hemorrhage >30cc was also associated with increased mortality, OR = 3.702 [1.575-8.956]). The proportion of patient hours with sustained ICP = 20 mmHg, and maximum ICP = 20 mmHg, were also directly correlated with increased mortality (OR = 64.99 [7.731-635.51]; and OR = 1.025 [1.004-1.047]). Poor functional outcome was predicted by concurrent presence of all five radiographic signs of elevated ICP (OR = 4.44 [1.514-14.183]) and presence of frontal lobe (OR = 2.951 [1.265-7.067]), subarachnoid (OR = 2.231 [1.067-4.717]), or intraventricular (OR = 2.249 [1.159-4.508]) hemorrhage. Time to death was modulated by total patient days of elevated ICP = 20 mmHg (Effect Size = 3.424 [1.500, 5.439]) in the first two weeks of hospitalization. CONCLUSIONS: ICP-related imaging variables can be prognosticate for moderate-severe TBI.

Association between abdominal adiposity and cognitive decline in older adults: a 10-year community-based study

ObjectivesThis study aimed to investigate the association between abdominal adiposity and change in cognitive function in community-dwelling older adults. Design, Setting, and ParticipantsThis longitudinal study included older adults aged ≥60 years without cognitive impairment who participated in the National Institute for Longevity Sciences – Longitudinal Study of Aging. MeasurementsCognitive function was evaluated biennially using the Mini-Mental State Examination (MMSE) over 10 years. Waist circumference (WC) was measured at the naval level, and subcutaneous fat area (SFA) and visceral fat area (VFA) were assessed using baseline computed tomography scans. WC, SFA, and VFA areas were stratified into sex-adjusted tertiles. A linear mixed model was applied separately for men and women. ResultsThis study included 873 older adults. In men, the groups with the highest levels of WC, SFA, and VFA exhibited a greater decline in MMSE score than the groups with the lowest levels (β [95% confidence interval]: WC, –0.12 [–0.23 to –0.01]; SFA, –0.13 [–0.24 to –0.02]; VFA, –0.11 [–0.22 to –0.01]). In women, the group with the highest level of WC and SFA showed a greater decline in MMSE score than the group with the lowest level (WC, –0.12 [–0.25 to –0.01]; SFA, –0.18 [–0.30 to –0.06]), but VFA was not associated with cognitive decline. ConclusionHigher WC, SFA, and VFA in men and higher WC and SFA in women were identified as risk factors for cognitive decline in later life, suggesting that abdominal adiposity involved in cognitive decline may differ according to sex.

Association between Immune Checkpoint Inhibitor Treatment Outcomes and Body Composition Factors in Metastatic Renal Cell Carcinoma Patients

Introduction: Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of metastatic renal cell carcinoma (mRCC); however, validating body composition-related biomarkers for their efficacy remains incomplete. We evaluated the association between body composition-related markers and the prognosis of patients with mRCC who received ICI-based first-line therapies. Patients and Methods: We retrospectively investigated 60 patients with mRCC who underwent ICI-based therapy as their first-line treatment between 2019 and 2023. Body composition variables, including skeletal muscle, subcutaneous fat, and visceral fat indices, were calculated using baseline computed tomography scans. Sarcopenia was defined according to sex-specific cut-off values of the skeletal mass index. The associations between body composition indices and objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were evaluated. Results: Patients with sarcopenia had lower ORR and DCR than those without sarcopenia (33.3% vs. 61.1%, p = 0.0436 and 52.4% vs. 94.4%, p = 0.0024, respectively). Patients with sarcopenia had a significantly shorter median PFS (14 months vs. not reached, p = 0.0020) and OS (21 months vs. not reached, p = 0.0023) than patients without sarcopenia did. Sarcopenia was a significant predictor of PFS (hazard ratio [HR], 4.31; 95% confidence interval [CI], 1.65–14.8; p = 0.0018) and OS (HR, 5.44; 95% CI, 1.83–23.4; p = 0.0013) along with poor IMDC risk. No association was found between the subcutaneous, visceral, and total fat indices and the therapeutic effect of ICI-based therapy. Conclusions: Sarcopenia was associated with a lower response and shorter survival rates in patients with mRCC who received first-line ICI-based therapy.

Prognostic utility of body composition parameters based on computed tomography analysis of advanced non-small cell lung cancer treated with immune checkpoint inhibitors

ObjectiveThe purpose of this study was to evaluate the prognostic impact of body composition parameters based on computed tomography (CT) in patients with non-small cell lung cancer (NSCLC) who received ICI treatment.MethodsThis retrospective study analyzed the data from advanced NSCLC patients treated with ICI therapy between 2013 and 2019. We included patients with NSCLC who underwent baseline CT scans. The exclusion criteria included patients who received three or more lines of chemotherapy, those with insufficient clinical information, or those without treatment response evaluation.ResultsA total of 136 patients were enrolled. Among the volumetric body composition parameters, patients in the highest quartiles (Q2–4) of the visceral fat index (VFI) exhibited a higher response rate to ICI therapy than those in the lowest quartile (Q1) of VFI (Q1 vs. Q2–4: 18.2% vs. 43.1%, p = 0.012). Patients with a VFI in Q2–4 had significantly prolonged progression-free survival (PFS) and overall survival (OS) (PFS, Q1 vs. Q2–4: 3.0 months vs. 6.4 months, p = 0.043; OS, Q1 vs. Q2–4: 5.6 months vs. 16.3 months, p = 0.004). Kaplan–Meier analysis based on the VFI and visceral fat Hounsfield unit (HU) revealed that patients with VFI in Q1 and HU in Q2–4 had the worst prognosis.ConclusionsVisceral fat volume is significantly associated with treatment outcomes in ICI-treated patients with NSCLC. Moreover, fat quality may impact the treatment outcomes. This finding underscores the potential significance of both fat compartments and fat quality as prognostic indicators.Critical relevance statementVisceral fat volume is significantly associated with treatment outcomes in ICI-treated patients with non-small cell lung cancer. Moreover, fat quality may impact the treatment outcomes. This finding underscores the potential significance of both fat compartments and fat quality as prognostic indicators.Graphical Key points• We found that visceral fat volume positively correlated with treatment response and survival in patients with non-small cell lung cancer receiving immune checkpoint inhibitors.• Additionally, a trend toward a negative correlation between visceral fat attenuation and survival was observed.• The findings highlight the prognostic utility of fat compartments and fat quality.

Ultraearly Intraventricular Hemorrhage Growth Predicts Early Neurologic Deterioration and Poor Functional Outcome After Acute Intracerebral Hemorrhage.

Background The presence of intraventricular hemorrhage (IVH) was extensively investigated and was associated with poor outcome in patients with intracerebral hemorrhage (ICH). However, the effect of the speed of ventricular bleeding on outcomes is unknown. Methods and Results We prospectively included patients with ICH who had baseline computed tomography scans within 6 hours after ictus between January 2016 and October 2021. The clinical characteristics were compared between patients with and without early neurologic deterioration (END). Ultraearly IVH growth (uIVHG) was defined as baseline IVH volume by onset-to-imaging time. The association between uIVHG and outcomes was assessed by using multivariable logistic regression analysis. We established the ultraearly IVH growth (uIVH) score and compared the areas under the receiver operating characteristic curves of the existing scores for predicting END. A total of 299 patients were finally enrolled. Of those, 38 patients (12.7%) experienced END at 24 hours and 89 patients (29.8%) had poor outcomes at 90 days. After adjustment for confounding factors, uIVHG (odds ratio, 1.061 [95% CI, 1.011-1.113]; P=0.016) was independently associated with END in multivariable analysis. A prediction score was developed on the basis of the logistic model. The uIVH score was developed as a sum of individual points (0-6) based on age, hematoma volume, National Institutes of Health Stroke Scale, hematoma expansion, and uIVHG ≥2.5 mL/h. In comparison with the ICH score and modified Emergency Department ICH Scale, the uIVH score exhibited best performance in the prediction of END. Conclusions uIVHG is associated with early neurologic deterioration and poor functional outcome in patients with ICH.

A mutation-based radiomics signature predicts response to imatinib in Gastrointestinal Stromal Tumors (GIST)

ObjectivesTo develop a mutation-based radiomics signature to predict response to imatinib in Gastrointestinal Stromal Tumors (GISTs). MethodsEighty-two patients with GIST were enrolled in this retrospective study, including 52 patients from one center that were used to develop the model, and 30 patients from a second center to validate it. Reference standard was the mutational status of tyrosine-protein kinase (KIT) and platelet-derived growth factor α (PDGFRA). Patients were dichotomized in imatinib sensitive (group 0 - mutation in KIT or PDGFRA, different from exon 18-D842V), and imatinib non-responsive (group 1 - PDGFRA exon 18-D842V mutation or absence of mutation in KIT/PDGFRA). Initially, 107 texture features were extracted from the tumor masks of baseline computed tomography scans. Different machine learning methods were then implemented to select the best combination of features for the development of the radiomics signature. ResultsThe best performance was obtained with the 5 features selected by the ANOVA model and the Bayes classifier, using a threshold of 0.36. With this setting the radiomics signature had an accuracy and precision for sensitive patients of 82 % (95 % CI:60–95) and 90 % (95 % CI:73–97), respectively. Conversely, a precision of 80 % (95 % CI:34–97) was obtained in non-responsive patients using a threshold of 0.9. Indeed, with the latter setting 4 patients out of 5 were correctly predicted as non-responders. ConclusionsThe results are a first step towards using radiomics to improve the management of patients with GIST, especially when tumor tissue is unavailable for molecular analysis or when molecular profiling is inconclusive.

Early Signs of Elevated Intracranial Pressure on Computed Tomography Correlate With Measured Intracranial Pressure in the Intensive Care Unit and Six-Month Outcome After Moderate to Severe Traumatic Brain Injury.

Traumatic brain injury (TBI) is a leading cause of death and disability in the United States. Early triage and treatment after TBI have been shown to improve outcome. Identifying patients at risk for increased intracranial pressure (ICP) via baseline computed tomography (CT) , however, has not been validated previously in a prospective dataset. We hypothesized that acute CT findings of elevated ICP, combined with direct ICP measurement, hold prognostic value in terms of six-month patient outcome after TBI. Data were obtained from the Progesterone for Traumatic Brain Injury, Experimental Clinical Treatment (ProTECTIII) multi-center clinical trial. Baseline CT scans for 881 participants were individually reviewed by a blinded central neuroradiologist. Five signs of elevated ICP were measured (sulcal obliteration, lateral ventricle compression, third ventricle compression, midline shift, and herniation). Associations between signs of increased ICP and outcomes (six-month functional outcome and death) were assessed. Secondary analyses of 354 patients with recorded ICP monitoring data available explored the relationships between hemorrhage phenotype/anatomic location, sustained ICP ≥20 mm Hg, and surgical intervention(s). Univariate and multi-variate logistic/linear regressions were performed; p < 0.05 is defined as statistically significant. Imaging characteristics associated with ICP in this cohort include sulcal obliteration (p = 0.029) and third ventricular compression (p = 0.039). Univariate regression analyses indicated that increasing combinations of the five defined signs of elevated ICP were associated with death, poor functional outcome, and time to death. There was also an increased likelihood of death if patients required craniotomy (odds ratio [OR] = 4.318, 95% confidence interval [1.330-16.030]) or hemicraniectomy (OR = 2.993 [1.109-8.482]). On multi-variate regression analyses, hemorrhage location was associated with death (posterior fossa, OR = 3.208 [1.120-9.188] and basal ganglia, OR = 3.079 [1.178-8.077]). Volume of hemorrhage >30 cc was also associated with increased death, OR = 3.702 [1.575-8.956]). The proportion of patient hours with sustained ICP ≥20 mm Hg, and maximum ICP ≥20 mm Hg were also directly correlated with increased death (OR = 6 4.99 [7.731-635.51]; and OR = 1.025 [1.004-1.047]), but not with functional outcome. Poor functional outcome was predicted by concurrent presence of all five radiographic signs of elevated ICP (OR = 4.44 [1.514-14.183]) and presence of frontal lobe (OR = 2.951 [1.265-7.067]), subarachnoid (OR = 2.231 [1.067-4.717]), or intraventricular (OR = 2.249 [1.159-4.508]) hemorrhage. Time to death was modulated by total patient days of elevated ICP ≥20 mm Hg (effect size = 3.424 [1.500, 5.439]) in the first two weeks of hospitalization. Sulcal obliteration and third ventricular compression, radiographic signs of elevated ICP, were significantly associated with measurements of ICP ≥20 mm Hg. These radiographic biomarkers were significantly associated with patient outcome. There is potential utility of ICP-related imaging variables in triage and prognostication for patients after moderate-severe TBI.

Proposal of early CT morphological criteria for response of liver metastases to systemic treatments in gastroenteropancreatic neuroendocrine tumors: Alternatives to RECIST.

RECIST 1.1 criteria are commonly used with computed tomography (CT) to evaluate the efficacy of systemic treatments in patients with neuroendocrine tumors (NETs) and liver metastases (LMs), but their relevance is questioned in this setting. We aimed to explore alternative criteria using different numbers of measured LMs and thresholds of size and density variation. We retrospectively studied patients with advanced pancreatic or small intestine NETs with LMs, treated with systemic treatment in the first-and/or second-line, without early progression, in 14 European expert centers. We compared time to treatment failure (TTF) between responders and non-responders according to various criteria defined by 0%, 10%, 20% or 30% decrease in the sum of LM size, and/or by 10%, 15% or 20% decrease in LM density, measured on two, three or five LMs, on baseline (≤1 month before treatment initiation) and first revaluation (≤6 months) contrast-enhanced CT scans. Multivariable Cox proportional hazard models were performed to adjust the association between response criteria and TTF on prognostic factors. We included 129 systemic treatments (long-acting somatostatin analogs 41.9%, chemotherapy 26.4%, targeted therapies 31.8%), administered as first-line (53.5%) or second-line therapies (46.5%) in 91 patients. A decrease ≥10% in the size of three LMs was the response criterion that best predicted prolonged TTF, with significance at multivariable analysis (HR 1.90; 95% CI: 1.06-3.40; p = .03). Conversely, response defined by RECIST 1.1 did not predict prolonged TTF (p = .91), and neither did criteria based on changes in LM density. A ≥10% decrease in size of three LMs could be a more clinically relevant criterion than the current 30% threshold utilized by RECIST 1.1 for the evaluation of treatment efficacy in patients with advanced NETs. Its implementation in clinical trials is mandatory for prospective validation. Criteria based on changes in LM density were not predictive of treatment efficacy. CLINICAL TRIAL REGISTRATION: Registered at CNIL-CERB, Assistance publique hopitaux de Paris as "E-NETNET-L-E-CT" July 2018. No number was assigned. Approved by the Medical Ethics Review Board of University Medical Center Groningen.

Relationship Between Pretreatment Body Composition and Clinical Outcomes in Patients With Metastatic Renal Cell Carcinoma Receiving First-Line Ipilimumab Plus Nivolumab

IntroductionBiomarkers are needed to identify patients with metastatic renal cell carcinoma (mRCC) most likely to benefit from immune checkpoint inhibitors. We examined associations between radiographically assessed body composition (BC) variables and body mass index (BMI) with clinical outcomes for patients with mRCC receiving first-line ipilimumab + nivolumab (ipi/nivo). Patients and MethodsWe retrospectively reviewed all patients with mRCC treated with first-line ipi/nivo at one institution before June 1, 2021 with an analyzable baseline computed tomography (CT) scan. BC variables (skeletal muscle index [SMI], subcutaneous adipose tissue index [SATI], and visceral adipose tissue index [VATI]) were measured using baseline CT scans. Relationships between BC variables and clinical outcomes were examined using Cox proportional hazard regression models. ResultsNinety-nine patients were analyzed (74% male, 64% overweight/obese, 75% low SMI). Controlling for age, IMDC risk, and sex (for BMI analyses), high vs. low SMI (HR=2.433, CI: 1.397-4.238, P=.0017), high vs. low SATI (HR=1.641, CI: 1.023-2.632, P=.0398), and obese BMI (≥ 30 kg/m2) vs. normal/overweight BMI (<30 kg/m2) (HR=1.859, CI: 1.156-2.989, P=.0105) were significantly associated with progression-free survival (PFS). Median overall survival (OS) for low SMI patients was higher (42.74 months, CI: 26.84, NR) than median OS for high SMI patients (27.01 months, CI: 15.28, NR) (adjusted HR=1.728, CI: 0.909-3.285, P=.0952). No BC variables were significantly associated with OS or objective response rate. ConclusionsLow SMI and low SATI were associated with significantly better PFS for patients with mRCC receiving first-line ipi/nivo. Radiographic BC variables may be useful prognostic biomarkers in this setting.

COMPARTMENTAL FEMUR CORTICAL THICKNESS IN OLDER ADULTS DIFFERS BY DEMOGRAPHICS AND PHYSICAL FUNCTION

Abstract Previous studies have examined the relationship between cortical bone properties and fracture risk in older populations, but they have yet to examine how these properties change within the femur. Most hip fractures are classified by their location: femoral neck, intertrochanteric, or subtrochanteric fractures. Since cortical thickness can vary throughout the femur, a quantitative method of examining thickness by region was developed using a cortical mapping approach applied to computed tomography (CT) scans. Subject-specific finite element (FE) models of proximal femurs were created from baseline CT scans of 107 older adults (ages 60 – 85; 70% White; 72% Female) with obesity as classified by BMI (33.8 ± 4 kg/m2). An existing FE model was morphed to the segmented geometry of each subject’s proximal femur. A nearest neighbor search assigned cortical thickness values to the nearest finite element model node. Cortical thickness was grouped into four femoral compartments: femoral head, femoral neck, intertrochanteric and subtrochanteric regions. Pairwise paired t-tests indicated that cortical thickness differed between femoral compartments (p &amp;lt; 0.05). Multivariate regression models showed greater cortical thicknesses in femoral head, neck, and intertrochanteric regions in African Americans compared to Whites (p &amp;lt; 0.05). Additionally, these models suggest an association between cortical thickness and physical function assessments, such as the timed up-and-go test and leg muscle strength test. Since cortical thickness is not constant throughout the femur, future studies can use the framework developed here to assess each compartment individually and investigate the relationships between cortical thickness, demographics, and functional assessments.

Automated Quantification of Compartmental Blood Volumes Enables Prediction of Delayed Cerebral Ischemia and Outcomes After Aneurysmal Subarachnoid Hemorrhage

The role of hemorrhage volume in risk of vasospasm, delayed cerebral ischemia (DCI), and poor outcomes after aneurysmal subarachnoid hemorrhage (SAH) is well established. However, the relative contribution of blood within individual compartments is unclear. We present an automated technique for measuring not only total but also volumes of blood in each major compartment after SAH. We trained convolutional neural networks to identify compartmental blood (cisterns, sulci, and ventricles) from baseline computed tomography scans of patients with SAH. We compared automated blood volumes against traditional markers of bleeding (modified Fisher score [mFS], Hijdra sum score [HSS]) in 190 SAH patients for prediction of vasospasm, DCI, and functional status (modified Rankin Scale) at hospital discharge. Combined cisternal and sulcal volume was better correlated with mFS and HSS than cisternal volume alone (ρ= 0.63 vs. 0.58 and 0.75 vs. 0.70, P < 0.001). Only blood volume in combined cisternal plus sulcal compartments was independently associated with DCI (OR 1.023 per mL, 95% CI 1.002-1.048), after adjusting for clinical factors while ventricular blood volume was not. Total and specifically sulcal blood volume was strongly associated with poor outcome (OR 1.03 per mL, 1.01-1.06, P= 0.006 and OR 1.04, 1.00-1.08 for sulcal) as was HSS (OR 1.06 per point, 1.00-1.12, P= 0.04), while mFS was not (P= 0.24). An automated imaging algorithm can measure the volume of bleeding after SAH within individual compartments, demonstrating cisternal plus sulcal (and not ventricular) blood contributes to risk of DCI/vasospasm. Automated blood volume was independently associated with outcome, while qualitative grading was not.

3D island sign on computed tomography predicts early perihematomal edema expansion and poor outcome in patients with intracerebral hemorrhage

Background and purposeTo determine the prognostics significance of the computed tomography (CT) 3D island sign for predicting early perihematomal edema (PHE) expansion and poor functional outcome in patients presenting with intracerebral hemorrhage (ICH). MethodsBetween July 2011 and March 2017, patients with intracerebral hemorrhage who had undergone baseline CT within 6 h after ICH symptom onsets and follow-up CT in our hospital were included. Two different readers independently assessed the presence of 3D island sign on admission CT scan of each patient. Multivariable logistic regression analysis was used to analyze association between 3D island sign and early perihematomal edema expansion and poor functional outcome, separately. ResultsA total of 214 patients who met the inclusion criteria were included in our study, 3D island sign was observed in 60 patients (28.0 %) on admission CT scan. The multivariate logistic regression analysis demonstrated that baseline hematoma volume, time to baseline and follow-up CT scans and the presence of 3D island sign were predictors of early PHE expansion. After adjusting for age, baseline hematoma and edema volume, time to baseline and follow-up CT scans, GCS on admission, presence of intraventricular hemorrhage (IVH) and systolic blood pressure, the 3D island sign was an independently imaging marker for poor outcome (OR, 2.803; 95 % confidence interval, 1.189–6.609; P = 0.018). ConclusionThe 3D island sign in patients with intracerebral hemorrhage was a reliable predictor for early perihematomal edema expansion and poor functional outcome. It may serve as a potential therapeutic target for intervention.

Structural and functional alterations of subjects with cement dust exposure: A longitudinal quantitative computed tomography-based study.

Cement dust exposure (CDE) can be a risk factor for pulmonary disease, causing changes in segmental airways and parenchymal lungs. This study investigates longitudinal alterations in quantitative computed tomography (CT)-based metrics due to CDE. We obtained CT-based airway structural and lung functional metrics from CDE subjects with baseline CT and follow-up CT scans performed three years later. From the CT, we extracted wall thickness (WT) and bifurcation angle (θ) at total lung capacity (TLC) and functional residual capacity (FRC), respectively. We also computed air volume (Vair), tissue volume (Vtissue), global lung shape, percentage of emphysema (Emph%), and more. Clinical measures were used to associate with CT-based metrics. Three years after their baseline, the pulmonary function tests of CDE subjects were similar or improved, but there were significant alterations in the CT-based structural and functional metrics. The follow-up CT scans showed changes in θ at most of the central airways; increased WT at the subgroup bronchi; smaller Vair at TLC at all except the right upper and lower lobes; smaller Vtissue at all lobes in TLC and FRC except for the upper lobes in FRC; smaller global lung shape; and greater Emph% at the right upper and lower lobes. CT-based structural and functional variables are more sensitive to the early identification of CDE subjects, while most clinical lung function changes were not noticeable. We speculate that the significant long-term changes in CT are uniquely observed in CDE subjects, different from smoking-induced structural changes.

Hemorrhage Enlargement Is More Frequent in the First 2 Hours: A Prehospital Mobile Stroke Unit Study.

Hematoma enlargement (HE) after intracerebral hemorrhage (ICH) is a therapeutic target for improving outcomes. Hemostatic therapies to prevent HE may be more effective the earlier they are attempted. An understanding of HE in first 1 to 2 hours specifically in the prehospital setting would help guide future treatment interventions in this time frame and setting. Patients with spontaneous ICH within 4 hours of symptom onset were prospectively evaluated between May 2014 and April 2020 as a prespecified substudy within a multicenter trial of prehospital mobile stroke unit versus standard management. Baseline computed tomography scans obtained <1, 1 to 2, and 2 to 4 hours postsymptom onset on the mobile stroke unit in the prehospital setting were compared with computed tomography scans repeated 1 hour later and at 24 hours in the hospital. HE was defined as >6 mL if baseline ICH volume was <20 mL and 33% increase if baseline volume >20 mL. The association between time from symptom onset to baseline computed tomography (hours) and HE was investigated using Wilcoxon rank-sum test when time was treated as a continuous variable and using Fisher exact test when time was categorized. Kruskal-Wallis and Wilcoxon rank-sum tests evaluated differences in baseline volumes and HE. Univariable and multivariable logistic regression analyses were conducted to identify factors associated with HE and variable selection was performed using cross-validated L1-regularized (Lasso regression). This study adhered to STROBE guidelines (Strengthening the Reporting of Observational Studies in Epidemiology) for cohort studies. One hundred thirty-nine patients were included. There was no difference between baseline ICH volumes obtained <1 hour (n=43) versus 1 to 2 hour (n=51) versus >2 hours (n=45) from symptom onset (median [interquartile range], 13 mL [6-24] versus 14 mL [6-30] versus 12 mL [4-19]; P=0.65). However, within the same 3 time epochs, initial hematoma growth (volume/time from onset) was greater with earlier baseline scanning (median [interquartile range], 17 mL/hour [9-35] versus 9 mL/hour [5-23]) versus 4 mL/hour [2-7]; P<0.001). Forty-nine patients had repeat scans 1 hour after baseline imaging (median, 2.3 hours [interquartile range. 1.9-3.1] after symptom onset). Eight patients (16%) had HE during that 1-hour interval; all of these occurred in patients with baseline imaging within 2 hours of onset (5/18=28% with baseline imaging within 1 hour, 3/18=17% within 1-2 hour, 0/13=0% >2 hours; P=0.02). HE did not occur between the scans repeated at 1 hour and 24 hours. No association between baseline variables and HE was detected in multivariable analyses. HE in the next hour occurs in 28% of ICH patients with baseline imaging within the first hour after symptom onset, and in 17% of those with baseline imaging between 1 and 2 hours. These patients would be a target for ultraearly hemostatic intervention.

Association between body composition and chemotherapy‐related toxicity in children with lymphoma and rhabdomyosarcoma

Body composition is associated with chemotherapy toxicity (chemotoxicity) in adults with cancer; this association remains unexplored in children with cancer. Using baseline computed tomography scans of 107 children with Hodgkin lymphoma (n = 45), non-Hodgkin lymphoma (n = 42), or rhabdomyosarcoma (n = 20), this study examined body composition (skeletal muscle index [SMI], skeletal muscle density [SMD], and height-adjusted total adipose tissue [hTAT]) to determine its association with chemotoxicity. Clinical characteristics and chemotoxicities were abstracted from medical records. Primary outcomes included grade 4 or higher hematologic toxicities and grade 3 or higher nonhematologic toxicities within 6 months of the diagnosis. Logistic regression models accounting for repeated measures were constructed to examine the association between body composition indices and chemotoxicities; adjustments were made for age at diagnosis, sex, race/ethnicity, cancer type, risk group, body mass index (measured as a percentile), or body surface area. The median SMI was 41.0 cm2 /m2 (range, 25.8-68.6 cm2 /m2 ), the median SMD was 54.1 HU (range, 35-69.4 HU), and the median hTAT was 19.5 cm2 /m2 (range, 0-226.7 cm2 /m2 ). Grade 4 or higher hematologic toxicities and grade 3 or higher nonhematologic toxicities were observed in 74.7% and 66.3% of the chemotherapy cycles, respectively. A higher SMD at diagnosis was associated with lower odds of grade 4 or higher hematologic toxicity (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.85-0.97; P = .004). SMI (OR, 0.99; 95% CI, 0.95-1.04; P = .7) and hTAT (OR, 1.00; 95% CI, 0.99-1.01; P = .9) were not associated with hematologic toxicities. Nonhematologic toxicities did not show any association with body composition. The association between low SMD and hematologic toxicities in children with lymphoma or rhabdomyosarcoma could be due to body composition-based biodistribution of chemotherapeutic agents and needs further investigation. Body composition at cancer diagnosis in children with lymphoma and rhabdomyosarcoma may provide information that could identify those at risk for serious side effects from chemotherapy. Routinely used measures such as body mass index and body surface area show poor correlations with body composition assessed via computed tomography scans.

Role of the Cardiophrenic Lymph Node Status After Neoadjuvant Chemotherapy in Primary Advanced Ovarian Cancer.

This study investigated the cardiophrenic lymph node (CPLN) status before and after neoadjuvant chemotherapy (NACT), as its presence seems to have a rather prognostic significance in patients with advanced ovarian cancer. The baseline computed tomography scans of 66 patients with advanced ovarian cancer primary treated with NACT between March 2015 and June 2020 were reviewed. A CPLN enlargement was defined as ≥5 mm. 44% (n=29) of the patients had enlarged CPLNs; 10.7% (n=3) showed a complete response, 71.4% (n=20) a partial response, and 17.9% (n=5) a stable disease after NACT. There was no significant difference between the response to NACT measured according to the status of CPLN compared to other biomarkers in the CPLN group. Patients with CPLN enlargement have a tendency to an impaired prognosis. The response of CPLN to NACT was comparable to the response of established biomarkers, adding a monitoring function to the CPLN.

Predictive radiomics signature for treatment response to nivolumab in patients with advanced renal cell carcinoma.

The anti-programmed cell death protein-1 (PD-1) immune checkpoint inhibitor nivolumab is currently approved for the treatment of patients with metastatic renal cell carcinoma (mRCC); approximately 25% of patients respond. We hypothesized that we could identify a biomarker of response using radiomics to train a machine learning classifier to predict nivolumab response outcomes. Patients with mRCC of different histologies treated with nivolumab in a single institution between 2013 and 2017 were retrospectively identified. Patients were labelled as responders (complete response [CR]/partial response [PR]/durable stable disease [SD]) or non-responders based on investigator tumor assessment using RECIST 1.1 criteria. For each patient, lesions were contoured from pre-treatment and first post-treatment computed tomography (CT) scans. This information was used to train a radial basis function support vector machine classifier to learn a prediction rule to distinguish responders from non-responders. The classifier was internally validated by a 10-fold nested cross-validation. Thirty-seven patients were identified; 27 (73%) met the inclusion criteria. One hundred and four lesions were contoured from these 27 patients. The median patient age was 56 years, 78% were male, 89% had clear-cell histology, 89% had prior nephrectomy, and 89% had prior systemic therapy. There were 19 responders vs. eight non-responders. The lesions selected were lymph nodes (60%), lung metastases (23%), and renal/adrenal metastases (17%). For the classifier trained on the baseline CT scans, 69% accuracy was achieved. For the classifier trained on the first post-treatment CT scans, 66% accuracy was achieved. The set of radiomic signatures was found to have limited ability to discriminate nivolumab responders from non-responders. The use of novel texture features (two-point correlation measure, two-point cluster measure, and minimum spanning tree measure) did not improve performance.

Accelerating Prediction of Malignant Cerebral Edema After Ischemic Stroke with Automated Image Analysis and Explainable Neural Networks.

Malignant cerebral edema is a devastating complication of stroke, resulting in deterioration and death if hemicraniectomy is not performed prior to herniation. Current approaches for predicting this relatively rare complication often require advanced imaging and still suffer from suboptimal performance. We performed a pilot study to evaluate whether neural networks incorporating data extracted from routine computed tomography (CT) imaging could enhance prediction of edema in a large diverse stroke cohort. An automated imaging pipeline retrospectively extracted volumetric data, including cerebrospinal fluid (CSF) volumes and the hemispheric CSF volume ratio, from baseline and 24h CT scans performed in participants of an international stroke cohort study. Fully connected and long short-term memory (LSTM) neural networks were trained using serial clinical and imaging data to predict those who would require hemicraniectomy or die with midline shift. The performance of these models was tested, in comparison with regression models and the Enhanced Detection of Edema in Malignant Anterior Circulation Stroke (EDEMA) score, using cross-validation to construct precision-recall curves. Twenty of 598 patients developed malignant edema (12 required surgery, 8 died). The regression model provided 95% recall but only 32% precision (area under the precision-recall curve [AUPRC] 0.74), similar to the EDEMA score (precision 28%, AUPRC 0.66). The fully connected network did not perform better (precision 33%, AUPRC 0.71), but the LSTM model provided 100% recall and 87% precision (AUPRC 0.97) in the overall cohort and the subgroup with a National Institutes of Health Stroke Scale (NIHSS) score ≥ 8 (p = 0.0001 vs. regression and fully connected models). Features providing the most predictive importance were the hemispheric CSF ratio and NIHSS score measured at 24h. An LSTM neural network incorporating volumetric data extracted from routine CT scans identified all cases of malignant cerebral edema by 24h after stroke, with significantly fewer false positives than a fully connected neural network, regression model, and the validated EDEMA score. This preliminary work requires prospective validation but provides proof of principle that a deep learning framework could assist in selecting patients for surgery prior to deterioration.

Abstract 432: Sarcopenia predicts dose-limiting toxicity in metastatic pancreatic cancer treated with gemcitabine plus nab-paclitaxel

Abstract Introduction: Gemcitabine (GEM) plus nab-paclitaxel (nab) has been shown to improve overall survival (OS) compared to GEM monotherapy in patients with metastatic pancreatic cancer. However, GEM/nab is associated with increased toxicity. Our study evaluated whether sarcopenia increased the likelihood of chemotherapy toxicity in pancreatic cancer treated with GEM/nab. Methods: A retrospective review was performed of all patients who received GEM/nab as first-line therapy for metastatic pancreatic cancer at a northern Alberta cancer institute (Canada) from 2014-2017. Patients were included if a computed tomography (CT) scan of the abdomen and pelvis was performed within 60 days of starting chemotherapy. Skeletal muscle surface area was measured at L3 on baseline CT scans and normalized for height to determine skeletal muscle index (SMI, cm2/m2). Dose-limiting toxicity (DLT) was defined as dose reduction or treatment discontinuation due to toxicity. Optimal stratification was used to establish sex-specific SMI cut-offs with DLT as an outcome. Results: 152 patients were included in the study. 88 patients (57.8%) were male and median age was 66.5 years (range 34-95). 62 patients (40.8%) experienced DLT. SMI cut-offs were determined as &amp;lt;48.0 cm2/m2 in males and &amp;lt;39.55 cm2/m2 in females. Sarcopenia prevalence using these cut-offs was 54.6%. DLT incidence was significantly higher in sarcopenic versus non-sarcopenic patients (55.4 vs. 23.2% respectively, p&amp;lt;0.001). In multivariate logistic regression accounting for advanced age (&amp;gt;65), sex, BMI category, and performance status (PS), sarcopenia significantly increased the likelihood of DLT (OR 7.21, 95% CI 3.02-17.24, p&amp;lt;0.001). Sarcopenia did not impact OS (HR 1.30, 95% CI 0.94-1.80, p=0.118) or progression-free survival (HR 0.66, 95% CI 0.42-1.03, p=0.071). Conclusion: In pancreatic cancer treated with GEM/nab, sarcopenic patients are significantly more likely to experience DLT, independent of age, sex, BMI, and PS. These findings could have implications for reduced chemotherapy dosing in sarcopenic patients. Citation Format: Susie Youn, Angela Chen, Vincent Ha, Carole Chambers, Dean T. Eurich, Michael McCall, Michael B. Sawyer. Sarcopenia predicts dose-limiting toxicity in metastatic pancreatic cancer treated with gemcitabine plus nab-paclitaxel [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 432.

Association of Satellite Sign with Postoperative Rebleeding in Patients Undergoing Stereotactic Minimally Invasive Surgery for Hypertensive Intracerebral Haemorrhage.

There are few studies regarding imaging markers for predicting postoperative rebleeding after stereotactic minimally invasive surgery (MIS) for hypertensive intracerebral haemorrhage (ICH), and little is known about the relationship between satellite sign on computed tomography (CT) scans and postoperative rebleeding after MIS. This study aimed to determine the value of the CT satellite sign in predicting postoperative rebleeding in patients with hypertensive ICH who undergo stereotactic MIS. We retrospectively examined and analysed 105 patients with hypertensive ICH who underwent standard stereotactic MIS for hematoma evacuation within 72 h following admission. Postoperative rebleeding occurred in 14 of 65 (21.5%) patients with the satellite sign on baseline CT, and in 5 of the 40 (12.5%) patients without the satellite sign. This difference was statistically significant. Positive and negative values of the satellite sign for predicting postoperative rebleeding were 21.5% and 87.5%, respectively. Multivariate logistic regression analysis verified that baseline ICH volume and intraventricular rupture were independent predictors of postoperative rebleeding. In conclusion, the satellite sign on baseline CT scans may not predict postoperative rebleeding following stereotactic MIS for hypertensive ICH.