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Dive into the research topics where Bradley S. Snyder is active.

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Featured researches published by Bradley S. Snyder.


Journal of Clinical Oncology | 2006

Early Invasive Cervical Cancer: Tumor Delineation by Magnetic Resonance Imaging, Computed Tomography, and Clinical Examination, Verified by Pathologic Results, in the ACRIN 6651/GOG 183 Intergroup Study

D. G. Mitchell; Bradley S. Snyder; Fergus V. Coakley; Caroline Reinhold; Gillian Thomas; Marco A. Amendola; Lawrence H. Schwartz; Paula J. Woodward; Harpreet K. Pannu; Hedvig Hricak

PURPOSE To compare magnetic resonance imaging (MRI), computed tomography (CT), and clinical examination for delineating early cervical cancer and for measuring tumor size. PATIENTS AND METHODS A 25-center study enrolled 208 patients with biopsy-proven invasive cervical cancer for MRI and CT before attempted curative radical hysterectomy. Each imaging study was interpreted prospectively by one onsite radiologist and retrospectively by four independent offsite radiologists, who were all blinded to surgical, histopathologic, and other imaging findings. Likelihood of cervical stromal and uterine body involvement was rated on a 5-point scale. Tumor size measurements were attempted in three axes. Surgical pathology was the standard of reference. RESULTS Neither MRI nor CT was accurate for evaluating cervical stroma. For uterine body involvement, the area under the receiver operating characteristic curve was higher for MRI than for CT for both prospective (0.80 v 0.66, respectively; P = .01) and retrospective (0.68 v 0.57, respectively; P = .02) readings. Retrospective readers could measure diameter by CT in 35% to 73% of patients and by MRI in 79% to 94% of patients. Prospective readers had the highest Spearman correlation coefficient with pathologic measurement for MRI (r(s) = 0.54), followed by CT (r(s) = 0.45) and clinical examination (r(s) = 0.37; P < .0001 for all). Spearman correlation of multiobserver diameter measurements for MRI (r(s) = 0.58; P < .0001) was double that for CT (r(s) = 0.27; P = .03). CONCLUSION In patients with cervical cancer, MRI is superior to CT and clinical examination for evaluating uterine body involvement and measuring tumor size, but no method was accurate for evaluating cervical stroma.


Journal of Clinical Oncology | 2005

Role of Imaging in Pretreatment Evaluation of Early Invasive Cervical Cancer: Results of the Intergroup Study American College of Radiology Imaging Network 6651–Gynecologic Oncology Group 183

Hedvig Hricak; Constantine Gatsonis; Dennis S. Chi; Marco A. Amendola; Kathy Brandt; Lawrence H. Schwartz; Susan Koelliker; Evan S. Siegelman; Jeffrey J. Brown; Robert B. McGhee; Revathy B. Iyer; Kenneth M. Vitellas; Bradley S. Snyder; Harry J. Long; James Fiorica; D. G. Mitchell

PURPOSE To compare magnetic resonance imaging (MRI) and computed tomography (CT) with each other and to International Federation of Gynecology and Obstetrics (FIGO) clinical staging in the pretreatment evaluation of early invasive cervical cancer, using surgicopathologic findings as the reference standard. PATIENTS AND METHODS This prospective multicenter clinical study was conducted by the American College of Radiology Imaging Network and the Gynecologic Oncology Group from March 2000 to November 2002; 25 United States health centers enrolled 208 consecutive patients with biopsy-confirmed cervical cancer of FIGO stage > or = IB who were scheduled for surgery based on clinical assessment. Patients underwent FIGO clinical staging, helical CT, and MRI. Surgicopathologic findings constituted the reference standard for statistical analysis. RESULTS Complete data were available for 172 patients; surgicopathologic findings were consistent with FIGO stages IA to IIA in 76% and stage > or = IIB in 21%. For the detection of advanced stage (> or = IIB), sensitivity was poor for FIGO clinical staging (29%), CT (42%), and MRI (53%); specificity was 99% for FIGO clinical staging, 82% for CT, and 74% for MRI; and negative predictive value was 84% for FIGO clinical staging, 84% for CT, and 85% for MRI. MRI (area under the receiver operating characteristic curve [AUC], 0.88) was significantly better than CT (AUC, 0.73) for detecting cervical tumors (P = .014). For 85% of patients, FIGO clinical staging forms were submitted after MRI and/or CT was performed. CONCLUSION CT and MRI performed similarly; both had lower staging accuracy than in prior single-institution studies. Accuracy of FIGO clinical staging was higher than previously reported. The temporal data suggest that FIGO clinical staging was influenced by CT and MRI findings.


Journal of Clinical Oncology | 2013

Prediction of Survival by [18F]Fluorodeoxyglucose Positron Emission Tomography in Patients With Locally Advanced Non–Small-Cell Lung Cancer Undergoing Definitive Chemoradiation Therapy: Results of the ACRIN 6668/RTOG 0235 Trial

Mitchell Machtay; Fenghai Duan; Barry A. Siegel; Bradley S. Snyder; Jeremy Gorelick; Janet S. Reddin; Reginald F. Munden; Douglas W. Johnson; Larry H. Wilf; Albert S. DeNittis; Nancy Sherwin; Kwan Ho Cho; Seok Ki Kim; Gregory Videtic; Donald R. Neumann; Ritsuko Komaki; Homer A. Macapinlac; Jeffrey D. Bradley; Abass Alavi

PURPOSE In this prospective National Cancer Institute-funded American College of Radiology Imaging Network/Radiation Therapy Oncology Group cooperative group trial, we hypothesized that standardized uptake value (SUV) on post-treatment [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) correlates with survival in stage III non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Patients received conventional concurrent platinum-based chemoradiotherapy without surgery; postradiotherapy consolidation chemotherapy was allowed. Post-treatment FDG-PET was performed at approximately 14 weeks after radiotherapy. SUVs were analyzed both as peak SUV (SUVpeak) and maximum SUV (SUVmax; both institutional and central review readings), with institutional SUVpeak as the primary end point. Relationships between the continuous and categorical (cutoff) SUVs and survival were analyzed using Cox proportional hazards multivariate models. RESULTS Of 250 enrolled patients (226 were evaluable for pretreatment SUV), 173 patients were evaluable for post-treatment SUV analyses. The 2-year survival rate for the entire population was 42.5%. Pretreatment SUVpeak and SUVmax (mean, 10.3 and 13.1, respectively) were not associated with survival. Mean post-treatment SUVpeak and SUVmax were 3.2 and 4.0, respectively. Post-treatment SUVpeak was associated with survival in a continuous variable model (hazard ratio, 1.087; 95% CI, 1.014 to 1.166; P = .020). When analyzed as a prespecified binary value (≤ v > 3.5), there was no association with survival. However, in exploratory analyses, significant results for survival were found using an SUVpeak cutoff of 5.0 (P = .041) or 7.0 (P < .001). All results were similar when SUVmax was used in univariate and multivariate models in place of SUVpeak. CONCLUSION Higher post-treatment tumor SUV (SUVpeak or SUVmax) is associated with worse survival in stage III NSCLC, although a clear cutoff value for routine clinical use as a prognostic factor is uncertain at this time.


Cancer | 2014

Impact of lung cancer screening results on participant health-related quality of life and state anxiety in the National Lung Screening Trial

Ilana F. Gareen; Fenghai Duan; Erin Greco; Bradley S. Snyder; Phillip M. Boiselle; Elyse R. Park; Dennis G. Fryback; Constantine Gatsonis

Low‐dose computed tomography (LDCT) lung screening has been associated with a 20% reduction in lung cancer mortality. A major barrier to the adoption of lung screening is the potential negative psychological impact of a false‐positive (FP) screen, occurring in 20% to 50% of those screened. The objective of this study was to assess the impact of abnormal findings on health‐related quality of life (HRQoL) and anxiety in the American College of Radiology (ACRIN)/National Lung Screening Trial (NLST).


Journal of Clinical Oncology | 2005

Utilization of Diagnostic Studies in the Pretreatment Evaluation of Invasive Cervical Cancer in the United States: Results of Intergroup Protocol ACRIN 6651/GOG 183

Marco A. Amendola; Hedvig Hricak; D. G. Mitchell; Bradley S. Snyder; Dennis S. Chi; Harry J. Long; James Fiorica; Constantine Gatsonis

PURPOSE To review the current utilization of diagnostic tests prescribed by the International Federation of Gynecology and Obstetrics (FIGO) clinical staging guidelines in the pretreatment work-up of invasive cervical cancer, and to compare the data with those of previous patterns of care studies. PATIENTS AND METHODS This interdisciplinary American College of Radiology Imaging Network/Gynecologic Oncology Group prospective clinical trial was conducted between March 1, 2000, and November 11, 2002. Twenty-five participating institutions, all from the United States, enrolled a total of 208 patients. Only patients scheduled for surgery with biopsy-confirmed cervical cancer of clinical FIGO stage IB or higher were eligible. The patterns of care data analysis was based on 197 patients who met all inclusion criteria. The conventional FIGO-recommended tests used for pre-enrollment FIGO clinical stage classification were at the discretion of the treating physician; overall frequency of use was tabulated for each test. RESULTS Use of cystoscopy (8.1%) and sigmoidoscopy or proctoscopy (8.6%) was significantly lower than in 1988 to 1989 (P < .0001 in each instance). Intravenous urography was used in only 1% of patients as compared with 42% in 1988 to 1989 and 91% in 1983. No patient included in the data analysis had barium enema or lymphangiography. Only 26.9% of patients had examination under anesthesia for FIGO clinical staging. CONCLUSION There is a large discrepancy between the diagnostic tests recommended by FIGO and the actual tests used for cervical cancer staging, suggesting a need to reassess the relevance of the FIGO guidelines to current clinical practice in the United States.


Radiology | 2015

Association of Coronary Artery Calcification and Mortality in the National Lung Screening Trial: A Comparison of Three Scoring Methods

Caroline Chiles; Fenghai Duan; Gregory W. Gladish; James G. Ravenel; Scott G. Baginski; Bradley S. Snyder; Sarah DeMello; Stephanie S. Desjardins; Reginald F. Munden

PURPOSE To evaluate three coronary artery calcification (CAC) scoring methods to assess risk of coronary heart disease (CHD) death and all-cause mortality in National Lung Screening Trial (NLST) participants across levels of CAC scores. MATERIALS AND METHODS The NLST was approved by the institutional review board at each participating institution, and informed consent was obtained from all participants. Image review was HIPAA compliant. Five cardiothoracic radiologists evaluated 1575 low-dose computed tomographic (CT) scans from three groups: 210 CHD deaths, 315 deaths not from CHD, and 1050 participants who were alive at conclusion of the trial. Radiologists used three scoring methods: overall visual assessment, segmented vessel-specific scoring, and Agatston scoring. Weighted Cox proportional hazards models were fit to evaluate the association between scoring methods and outcomes. RESULTS In multivariate analysis of time to CHD death, Agatston scores of 1-100, 101-1000, and greater than 1000 (reference category 0) were associated with hazard ratios of 1.27 (95% confidence interval: 0.69, 2.53), 3.57 (95% confidence interval: 2.14, 7.48), and 6.63 (95% confidence interval: 3.57, 14.97), respectively; hazard ratios for summed segmented vessel-specific scores of 1-5, 6-11, and 12-30 (reference category 0) were 1.72 (95% confidence interval: 1.05, 3.34), 5.11 (95% confidence interval: 2.92, 10.94), and 6.10 (95% confidence interval: 3.19, 14.05), respectively; and hazard ratios for overall visual assessment of mild, moderate, or heavy (reference category none) were 2.09 (95% confidence interval: 1.30, 4.16), 3.86 (95% confidence interval: 2.02, 8.20), and 6.95 (95% confidence interval: 3.73, 15.67), respectively. CONCLUSION By using low-dose CT performed for lung cancer screening in older, heavy smokers, a simple visual assessment of CAC can be generated for risk assessment of CHD death and all-cause mortality, which is comparable to Agatston scoring and strongly associated with outcome.


Radiology | 2013

Whole-Body MR Imaging for Staging of Malignant Tumors in Pediatric Patients: Results of the American College of Radiology Imaging Network 6660 Trial

Marilyn J. Siegel; Suddhasatta Acharyya; Frederic A. Hoffer; J. Brad Wyly; Alison M. Friedmann; Bradley S. Snyder; Paul Babyn; Geetika Khanna; Barry A. Siegel

PURPOSE To compare whole-body magnetic resonance (MR) imaging with conventional imaging for detection of distant metastases in pediatric patients with common malignant tumors. MATERIALS AND METHODS This institutional review board-approved, HIPAA-compliant, multicenter prospective cohort study included 188 patients (109 male, 79 female; mean age, 10.2 years; range, < 1 to 21 years) with newly diagnosed lymphoma, neuroblastoma, or soft-tissue sarcoma. Informed consent was obtained and all patients underwent noncontrast material-enhanced whole-body MR imaging and standard-practice conventional imaging. All images were reviewed centrally by 10 pairs of readers. An independent panel verified the presence or absence of distant metastases. Detection of metastasis with whole-body MR and conventional imaging was quantified by using the area under the receiver operating characteristic curve (AUC). The effects of tumor subtype, patient age, and distant skeletal and pulmonary disease on diagnostic accuracy were also analyzed. RESULTS Of the 134 eligible patients, 66 (33 positive and 33 negative for metastasis) were selected for image review and analysis. Whole-body MR imaging did not meet the noninferiority criterion for accuracy when compared with conventional imaging for detection of metastasis (difference between average AUCs was -0.03 [95% confidence interval: -0.10, 0.04]); however, the average AUC for solid tumors was significantly higher than that for lymphomas (P = .006). More skeletal metastases were detected by using whole-body MR imaging than by using conventional imaging (P = .03), but fewer lung metastases were detected (P < .001). Patient age did not affect accuracy. CONCLUSION The noninferior accuracy for diagnosis of distant metastasis in patients with common pediatric tumors was not established for the use of whole-body MR imaging compared with conventional methods. However, improved accuracy was seen with whole-body MR imaging in patients with nonlymphomatous tumors.


Neuro-oncology | 2015

Dynamic susceptibility contrast MRI measures of relative cerebral blood volume as a prognostic marker for overall survival in recurrent glioblastoma: results from the ACRIN 6677/RTOG 0625 multicenter trial

Kathleen M. Schmainda; Zheng Zhang; Melissa Prah; Bradley S. Snyder; Mark R. Gilbert; A. Gregory Sorensen; Daniel P. Barboriak; Jerrold L. Boxerman

BACKGROUND The study goal was to determine whether changes in relative cerebral blood volume (rCBV) derived from dynamic susceptibility contrast (DSC) MRI are predictive of overall survival (OS) in patients with recurrent glioblastoma multiforme (GBM) when measured 2, 8, and 16 weeks after treatment initiation. METHODS Patients with recurrent GBM (37/123) enrolled in ACRIN 6677/RTOG 0625, a multicenter, randomized, phase II trial of bevacizumab with irinotecan or temozolomide, consented to DSC-MRI plus conventional MRI, 21 with DSC-MRI at baseline and at least 1 postbaseline scan. Contrast-enhancing regions of interest were determined semi-automatically using pre- and postcontrast T1-weighted images. Mean tumor rCBV normalized to white matter (nRCBV) and standardized rCBV (sRCBV) were determined for these regions of interest. The OS rates for patients with positive versus negative changes from baseline in nRCBV and sRCBV were compared using Wilcoxon rank-sum and Kaplan-Meier survival estimates with log-rank tests. RESULTS Patients surviving at least 1 year (OS-1) had significantly larger decreases in nRCBV at week 2 (P = .0451) and sRCBV at week 16 (P = .014). Receiver operating characteristic analysis found the percent changes of nRCBV and sRCBV at week 2 and sRCBV at week 16, but not rCBV data at week 8, to be good prognostic markers for OS-1. Patients with positive change from baseline rCBV had significantly shorter OS than those with negative change at both week 2 and week 16 (P = .0015 and P = .0067 for nRCBV and P = .0251 and P = .0004 for sRCBV, respectively). CONCLUSIONS Early decreases in rCBV are predictive of improved survival in patients with recurrent GBM treated with bevacizumab.


Gynecologic Oncology | 2009

Early invasive cervical cancer: MRI and CT predictors of lymphatic metastases in the ACRIN 6651/GOG 183 intergroup study

D. G. Mitchell; Bradley S. Snyder; Fergus V. Coakley; Caroline Reinhold; Gillian Thomas; Marco A. Amendola; Lawrence H. Schwartz; Paula J. Woodward; Harpreet K. Pannu; Mostafa Atri; Hedvig Hricak

PURPOSE To compare MRI, CT, clinical exam and histopathological analysis for predicting lymph node involvement in women with cervical carcinoma, verified by lymphadenectomy. METHODS A 25-center ACRIN/GOG study enrolled 208 patients with biopsy-proven invasive cervical cancer for MRI and CT prior to attempted curative radical hysterectomy. Each imaging study was interpreted prospectively by one onsite radiologist, and retrospectively by 4 independent offsite radiologists, all blinded to surgical, histopathological and other imaging findings. Likelihood of parametrial and uterine body involvement was rated on a 5-point scale. Tumor size measurements were attempted in 3 axes. Association with histologic lymph node involvement, scored as absent, pelvic only and common iliac or paraaortic, was evaluated using Cochran-Mantel Haenszel statistics, univariate and multivariate logistic regression, generalized estimating equations, accuracy statistics and ROC analysis. RESULTS Lymphatic metastases were found in 34% of women; 13% had common iliac nodal metastases, and 9% had paraortic nodal metastases. Based on the retrospective multi-observer re-reads, the average AUC for predicting histologic lymph node involvement based on tumor size was higher for MRI versus CT, although formal statistic comparisons could not be conducted. Multivariate analysis showed improved model fit incorporating predictors from MRI, but not from CT, over and above the initial clinical and biopsy predictors, although the increase in discriminatory ability was not statistically significant. CONCLUSION MRI findings may help predict the presence of histologic lymph node involvement in women with early invasive cervical carcinoma, thus providing important prognostic information.


Neuro-oncology | 2013

Early post-bevacizumab progression on contrast-enhanced MRI as a prognostic marker for overall survival in recurrent glioblastoma: results from the ACRIN 6677/RTOG 0625 Central Reader Study

Jerrold L. Boxerman; Zheng Zhang; Yair Safriel; Mykol Larvie; Bradley S. Snyder; Rajan Jain; T. lINDA Chi; A. Gregory Sorensen; Mark R. Gilbert; Daniel P. Barboriak

BACKGROUND RTOG 0625/ACRIN 6677 is a multicenter, randomized, phase II trial of bevacizumab with irinotecan or temozolomide in recurrent glioblastoma (GBM). This study investigated whether early posttreatment progression on FLAIR or postcontrast MRI assessed by central reading predicts overall survival (OS). METHODS Of 123 enrolled patients, 107 had baseline and at least 1 posttreatment MRI. Two central neuroradiologists serially measured bidimensional (2D) and volumetric (3D) enhancement on postcontrast T1-weighted images and volume of FLAIR hyperintensity. Progression status on all posttreatment MRIs was determined using Macdonald and RANO imaging threshold criteria, with a third neuroradiologist adjudicating discrepancies of both progression occurrence and timing. For each MRI pulse sequence, Kaplan-Meier survival estimates and log-rank test were used to compare OS between cases with or without radiologic progression. RESULTS Radiologic progression occurred after 2 chemotherapy cycles (8 weeks) in 9 of 97 (9%), 9 of 73 (12%), and 11 of 98 (11%) 2D-T1, 3D-T1, and FLAIR cases, respectively, and 34 of 80 (43%), 21 of 58 (36%), and 37 of 79 (47%) corresponding cases after 4 cycles (16 weeks). Median OS among patients progressing at 8 or 16 weeks was significantly less than that among nonprogressors, as determined on 2D-T1 (114 vs 278 days and 214 vs 426 days, respectively; P < .0001 for both) and 3D-T1 (117 vs 306 days [P < .0001] and 223 vs 448 days [P = .0003], respectively) but not on FLAIR (201 vs 276 days [P = .38] and 303 vs 321 days [P = .13], respectively). CONCLUSION Early progression on 2D-T1 and 3D-T1, but not FLAIR MRI, after 8 and 16 weeks of anti-vascular endothelial growth factor therapy has highly significant prognostic value for OS in recurrent GBM.

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Barry A. Siegel

Washington University in St. Louis

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Abass Alavi

Philadelphia University

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Jeffrey D. Bradley

Washington University in St. Louis

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Albert S. DeNittis

Lankenau Institute for Medical Research

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D. G. Mitchell

Johns Hopkins University Applied Physics Laboratory

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Hedvig Hricak

Memorial Sloan Kettering Cancer Center

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