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Dive into the research topics where Gulce Askin is active.

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Featured researches published by Gulce Askin.


Neuro-oncology | 2017

MR perfusion-weighted imaging in the evaluation of high-grade gliomas after treatment: a systematic review and meta-analysis

Praneil Patel; Hediyeh Baradaran; Diana Delgado; Gulce Askin; Paul J. Christos; Apostolos John Tsiouris; Ajay Gupta

Background. Distinction between tumor and treatment related changes is crucial for clinical management of patients with high-grade gliomas. Our purpose was to evaluate whether dynamic susceptibility contrast-enhanced (DSC) and dynamic contrast enhanced (DCE) perfusion-weighted imaging (PWI) metrics can effectively differentiate between recurrent tumor and posttreatment changes within the enhancing signal abnormality on conventional MRI. Methods. A comprehensive literature search was performed for studies evaluating PWI-based differentiation of recurrent tumor and posttreatment changes in patients with high-grade gliomas (World Health Organization grades III and IV). Only studies published in the “temozolomide era” beginning in 2005 were included. Summary estimates of diagnostic accuracy were obtained by using a random-effects model. Results. Of 1581 abstracts screened, 28 articles were included. The pooled sensitivities and specificities of each studys best performing parameter were 90% and 88% (95% CI: 0.85–0.94; 0.83–0.92) and 89% and 85% (95% CI: 0.78–0.96; 0.77–0.91) for DSC and DCE, respectively. The pooled sensitivities and specificities for detecting tumor recurrence using the 2 most commonly evaluated parameters, mean relative cerebral blood volume (rCBV) (threshold range, 0.9–2.15) and maximum rCBV (threshold range, 1.49–3.1), were 88% and 88% (95% CI: 0.81–0.94; 0.78–0.95) and 93% and 76% (95% CI: 0.86–0.98; 0.66–0.85), respectively. Conclusions. PWI-derived thresholds separating viable tumor from treatment changes demonstrate relatively good accuracy in individual studies. However, because of significant variability in optimal reported thresholds and other limitations in the existing body of literature, further investigation and standardization is needed before implementing any particular quantitative PWI strategy across institutions.


Stroke | 2016

Silent Brain Infarction in Patients With Asymptomatic Carotid Artery Atherosclerotic Disease

Hediyeh Baradaran; Gino Gialdini; Edward E. Mtui; Gulce Askin; Hooman Kamel; Ajay Gupta

Background and Purpose— The relationship between carotid atherosclerosis and ipsilateral silent brain infarction (SBI) is unclear. We tested the hypothesis that extracranial internal carotid artery (ICA) stenosis is associated with a greater prevalence of SBI in the cerebral hemisphere ipsilateral to ICA disease compared with the unaffected, contralateral side. Methods— We identified patients with unilateral extracranial ICA stenosis ≥50% on angiography by standard imaging criteria. We included patients with recent brain magnetic resonance imaging who had no previous history of stroke or transient ischemic attack. Blinded readers ascertained the presence of anterior circulation SBIs. SBI was defined as either a cavitary lacunar infarction in the white or deep gray matter or cortical infarction defined by T2 hyperintense signal in cortical gray matter. The Wilcoxon signed-rank test was used to compare SBI in the cerebral hemispheres and Cohen &kgr; to assess inter-rater reliability of SBI evaluation. Results— Among 104 patients, we found a higher prevalence of SBIs ipsilateral to ICA disease (33%) compared with the contralateral side (20.8%; P=0.0067). There was no significant difference in the prevalence of lacunar SBIs (including both white and deep gray matter) between hemispheres (P=0.109), but there was a significantly higher prevalence of cortical SBIs occurring downstream from ICA disease (P=0.0045). High inter-rater reliability was observed (&kgr;=0.818). Conclusions— Patients with asymptomatic ICA disease demonstrate a higher prevalence of SBI downstream from their ICA atherosclerotic disease compared with the contralateral side but only of the cortical and not lacunar SBI subtype.


Vascular Medicine | 2017

A pulmonary embolism response team’s initial 20 month experience treating 87 patients with submassive and massive pulmonary embolism:

Akhilesh K. Sista; Oren Friedman; Eda Dou; Brendan Denvir; Gulce Askin; Jamie Stern; Jaclyn L. Estes; Arash Salemi; Ronald S. Winokur; James M. Horowitz

Pulmonary Embolism Response Teams (PERTs) have emerged to provide rapid multidisciplinary assessment and treatment of PE patients. However, descriptive institutional experience and preliminary outcomes data from such teams are sparse. PERT activations were identified through a retrospective review. Only confirmed submassive or massive PEs were included in the data analysis. In addition to baseline variables, the therapeutic intervention, length of stay (LOS), in-hospital mortality, and bleeding rate/severity were recorded. A total of 124 PERT activations occurred over 20 months: 43 in the first 10 months and 81 in the next 10. A total of 87 submassive (90.8%) and massive (9.2%) PE patients were included. The median age was 65 (51–75 IQR) years. Catheter-directed thrombolysis (CDT) was administered to 25 patients, systemic thrombolysis (ST) to six, and anticoagulation alone (AC) to 54. The median ICU stay and overall LOS were 6 (3–10 IQR) and 7 (4–14 IQR) days, respectively, with no association with any variables except a brain natriuretic peptide (BNP) >100 pg/mL (p=0.008 ICU LOS; p=0.047 overall LOS). Twelve patients (13.7%) died in the hospital, nine of whom had metastatic or brain cancer, with a median overall LOS of 13 (11–17 IQR) days. There were five major bleeds: one in the CDT group, one in the ST group, and three in the AC group. Overall, (1) PERT activations increased after the first 10 months; (2) BNP >100 pg/mL was associated with a longer LOS; (3) rates of mortality and bleeding did not correlate with treatment; and (4) the majority of in-hospital deaths occurred in patients with advanced cancer.


Pediatric Radiology | 2017

Diagnostic utility of intravenous contrast for MR imaging in pediatric appendicitis

Gray R. Lyons; Pooja Renjen; Gulce Askin; Ashley E. Giambrone; Debra Beneck; Arzu Kovanlikaya

BackgroundMagnetic resonance imaging (MRI) is increasingly employed as a diagnostic modality for suspected appendicitis in children. However, there is uncertainty as to which MRI sequences are sufficient for safe, timely and accurate diagnosis. Several recent studies have described different MRI protocols, including exams both with and without the use of intravenous contrast.ObjectiveWe hypothesized that intravenous contrast may be useful in some patients but could be safely omitted in others.Materials and methodsAll MRI examinations (n=112) performed at our institution for evaluating appendicitis in children were retrospectively reevaluated. Exams were reread by pediatric radiologists under three conditions: With postcontrast images, Without postcontrast images, and Without/With – selective use of postcontrast sequences only when needed for diagnostic certainty. Samples were scored as positive, negative or equivocal for appendicitis. Findings were compared to pathological or clinical follow-up in the medical record.ResultsWithout the use of intravenous contrast yielded more equivocal results (12.4%) compared to With contrast (3.4%). By selectively using postcontrast sequences, the Without/With group yielded fewer equivocal results (1.1%) compared to Without while also reducing contrast use 79.8% compared to the With contrast group. No significant differences in conditional sensitivity or conditional specificity were detected among the three groups.ConclusionMRI diagnosis of acute appendicitis can be performed without contrast for most patients; injection of contrast can be reserved for only those patients with equivocal non-contrast imaging.


Cancer Epidemiology and Prevention Biomarkers | 2017

Vasectomy and Risk of Prostate Cancer in a Screening Trial

Jonathan Shoag; Oleksander Savenkov; Paul J. Christos; Sameer Mittal; Joshua A. Halpern; Gulce Askin; Daniel Shoag; Ron Golan; Daniel Lee; Padraic O'Malley; Bobby Najari; Brian H. Eisner; Jim C. Hu; Douglas S. Scherr; Peter N. Schlegel; Christopher E. Barbieri

Background: Vasectomy has been implicated as a risk factor for prostate cancer in multiple epidemiologic studies over the past 25 years. Whether this relationship is causal remains unclear. This study examines the association between vasectomy and prostate cancer in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, which randomized men to usual care or annual prostate cancer screening. Methods: We performed a retrospective analysis of 13-year screening and outcomes data from the PLCO trial. Multivariable Cox proportional hazards regression stratified by study arm and age at vasectomy was performed. Results: There was an increased risk of prostate cancer in men who had undergone a vasectomy and were randomized to the usual care arm of the study (adjusted HR, 1.11; 95% confidence interval, 1.03–1.20; P = 0.008). There was no association between vasectomy and diagnosis of prostate cancer in men randomized to the prostate cancer screening arm. Only men undergoing vasectomy at an older age in the usual care arm of the study, but not the prostate cancer screening arm, were at increased risk of being diagnosed with prostate cancer. Conclusions: Vasectomy was not associated with prostate cancer risk among men who were screened for prostate cancer as part of a clinical trial, but was associated with prostate cancer detection in men receiving usual care. Impact: The positive association between vasectomy and prostate cancer is likely related to increased detection of prostate cancer based on patterns of care rather than a biological effect of vasectomy on prostate cancer development. Cancer Epidemiol Biomarkers Prev; 26(11); 1653–9. ©2017 AACR.


Archives of Physical Medicine and Rehabilitation | 2017

Association Between 2 Measures of Cognitive Instrumental Activities of Daily Living and Their Relation to the Montreal Cognitive Assessment in Persons With Stroke

Joan Toglia; Gulce Askin; Linda M. Gerber; Michael Taub; Andrea R. Mastrogiovanni; Michael W. O'Dell

OBJECTIVES To explore the relation between a computer adaptive functional cognitive questionnaire and a performance-based measure of cognitive instrumental activities of daily living (C-IADL) and to determine whether the Montreal Cognitive Assessment (MoCA) at admission can identify those with C-IADL difficulties at discharge. DESIGN Prospective cohort study. SETTING Acute inpatient rehabilitation unit of an academic medical center. PARTICIPANTS Inpatients (N=148) with a diagnosis of stroke (mean age, 68y; median, 13d poststroke) who had mild cognitive and neurological deficits. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Admission cognitive status was assessed by the MoCA. C-IADL at discharge was assessed by the Executive Function Performance Test (EFPT) bill paying task and Activity Measure of Post-Acute Care (AM-PAC) Applied Cognition scale. RESULTS Greater cognitive impairment on the MoCA was associated with more assistance on the EFPT bill paying task (ρ=-.63; P<.01) and AM-PAC Applied Cognition scale (ρ=-.43; P<.01). This relation was nonsignificant for higher MoCA scores and EFPT bill paying task scores. The AM-PAC Applied Cognition scale and the EFPT bill paying task had low agreement in classifying functional performance (Cohens κ=.20). A receiver operating characteristic curve identified optimal MoCA cutoff scores of 20 and 21 for classifying EFPT bill paying task status and AM-PAC Applied Cognition scale status, respectively. For values above 20 and 21, sensitivity increased whereas specificity decreased for classifying functional deficits. Approximately one third of the participants demonstrated C-IADL deficits on at least 1 C-IADL measure at discharge despite having a MoCA score of ≥26 at admission. CONCLUSIONS Questionnaire and performance-based methods of assessment appear to yield different estimates of C-IADL. Low MoCA scores (<20) are more likely to identify those with C-IADL deficits on the EFPT bill paying task. The results suggest that C-IADL should be assessed in those who have mild or no cognitive difficulties at admission.


Laryngoscope | 2016

Vocal fold varices and risk of hemorrhage

Christopher Guan‐Zhong Tang; Gulce Askin; Paul J. Christos; Lucian Sulica

To establish risk of hemorrhage in patients with varices compared to those without, determine additional risk factors, and make evidence‐based treatment recommendations.


Clinical Imaging | 2019

Diffusion tensor imaging and quantitative susceptibility mapping as diagnostic tools for motor neuron disorders

Elizabeth K. Weidman; Andrew D. Schweitzer; Sumit Niogi; Emily J. Brady; Anna Starikov; Gulce Askin; Mona Shahbazi; Yi Wang; Dale J. Lange; Apostolos John Tsiouris

PURPOSE Diffusion tensor imaging (DTI) and quantitative susceptibility mapping (QSM) have been proposed as methods to aid in the diagnosis of amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS), both diseases affecting upper motor neurons. We test the performance of DTI and QSM alone and in combination to distinguish patients with diseases affecting upper motor neurons (ALS/PLS) from patients with other motor symptom-predominant neurologic disorders. METHODS 3.0 Tesla MRI with DTI and QSM in patients referred to a subspecialty neurology clinic for evaluation of motor symptom-predominant neurologic disorders were retrospectively reviewed. Corticospinal tract fractional anisotropy and maximum motor cortex susceptibility were measured. Subjects were categorized by diagnosis and imaging metrics were compared between groups using Students t-tests. Receiver operating characteristic curves were generated for imaging metrics alone and in combination. RESULTS MRI scans for 43 patients with ALS or PLS and 15 patients with motor symptom predominant, non-upper motor neuron disease (mimics) were reviewed. Fractional anisotropy was lower (0.57 vs. 0.60, p < 0.01) and maximum motor cortex magnetic susceptibility higher (64.4 vs. 52.7, p = 0.01) in patients with ALS/PLS compared to mimics. There was no significant difference in area under the curve for these metrics alone (0.73, 0.63; p > 0.05) or in combination (0.75; p > 0.05). CONCLUSION We found significant differences in DTI and QSM metrics in patients with diseases affecting upper motor neurons (ALS/PLS) compared to mimics, but no significant difference in the performance of these metrics in diagnosing ALS/PLS compared to mimics.


Leukemia & Lymphoma | 2018

CD25 expression and outcomes in older patients with acute myelogenous leukemia treated with plerixafor and decitabine

John N. Allan; Gail J. Roboz; Gulce Askin; Ellen K. Ritchie; Joseph M. Scandura; Paul J. Christos; Duane C. Hassane; Monica L. Guzman

Abstract We investigated CD25 expression in older (≥60 years) patients with new acute myelogenous leukemia treated with decitabine and plerixafor. Patients resistant to therapy or survival ≤1 year had significantly higher percentages of CD25pos myeloid blasts in baseline bone marrow. CD25pos patients had an increased odds of resistance compared to CD25neg patients (p = .015). In univariate analysis, we found CD25pos patients had inferior survival compared to CD25neg (p = .002). In patients with intermediate risk cytogenetics, CD25pos status stratified patients associating with inferior survival (p = .002). In multivariable analysis, CD25 and TP53 mutations trended towards predicting remission to therapy but were not predictive of survival. Only remission status, ASXL1 and TET2 mutations were found to independently predict overall survival (OS). We conclude CD25 expression identifies patients at risk for resistance to hypomethylating chemotherapy but does not independently predict OS in an older AML population treated with decitabine and plerixafor.


Journal of Vascular and Interventional Radiology | 2018

Clinical Outcomes after Pulmonary Cryoablation with the Use of a Triple Freeze Protocol

Gray R. Lyons; Gulce Askin; Bradley B. Pua

PURPOSE To elucidate clinical variables associated with safety and efficacy in patients after cryoablation of pulmonary tumors with the use of a triple freeze protocol. MATERIALS AND METHODS Percutaneous cryoablation of pulmonary tumors was performed using Galil Medical cryoprobes (Arden Hills, Minnesota) with a triple freeze protocol: 67 nodules in 42 patients were treated at a single institution from 2012 to 2016. Average nodule diameter was 1.6 cm (range 0.4-5.9); 13 nodules (19.4%) were pathologically determined to be a primary lung malignancy, whereas 54 (80.6%) were metastatic nodules of extrapulmonary origin. Average patient age was 68.1 years (range 39.6-89.6), and the male-female ratio was 1.3:1. Ipsilateral thoracic surgery, intervention, or radiotherapy had been performed before the first cryoablation in 18 patients (42.9%). Mean imaging follow-up was 326 days (range 9-1,152). RESULTS Pneumothorax occurred in 19 cases (33.9%), 7 (12.5%) requiring chest tube, the likelihood of which was significantly greater in patients with 3 or more cryoprobes (P < .01). Local tumor recurrence/residual disease occurred in 6 cases (9.0%). Local tumor recurrence was not seen after ablation of nodules measuring <1.0 cm at the time of procedure, a significant difference from the recurrence ratee of 14.3% for nodules measuring ≥1.0 cm (P < .05). Likelihood of tumor recurrence/residual disease did not correlate with tumor pathology, tumor location, or procedural factors. The estimated marginal probabilities of local recurrence were 11.4%, 11.4%, and 38.1% at 1, 2, and 3 years after ablation, respectively. CONCLUSIONS Cryoablation of pulmonary tumors with the use of a triple freeze protocol is a viable modality with low recurrence and complication rates.

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Andrew D. Schweitzer

NewYork–Presbyterian Hospital

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Anna Knobel

Memorial Sloan Kettering Cancer Center

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