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Limited By:	Author = Wolsztynski, Eric;

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Assessment of the prognostic value of radiomic features in 18F-FMISO PET imaging of hypoxia in postsurgery brain cancer patients: secondary analysis of imaging data from a single-center study and the multicenter ACRIN 6684 trial (2020)

Muzi, Mark; Wolsztynski, Eric; Fink, James R.; O'Sullivan, Janet N.; O'Sulliv...

Muzi, Mark; Wolsztynski, Eric; Fink, James R.; O'Sullivan, Janet N.; O'Sullivan, Finbarr; Krohn, Kenneth A.; Mankoff, David A.

Abstract:

Hypoxia is associated with resistance to radiotherapy and chemotherapy in malignant gliomas, and it can be imaged by positron emission tomography with 18F-fluoromisonidazole (18F-FMISO). Previous results for patients with brain cancer imaged with 18F-FMISO at a single center before conventional chemoradiotherapy showed that tumor uptake via T/Bmax (tissue SUVmax/blood SUV) and hypoxic volume (HV) was associated with poor survival. However, in a multicenter clinical trial (ACRIN 6684), traditional uptake parameters were not found to be prognostically significant, but tumor SUVpeak did predict survival at 1 year. The present analysis considered both study cohorts to reconcile key differences and examine the potential utility of adding radiomic features as prognostic variables for outcome prediction on the combined cohort of 72 patients with brain cancer (30 University of Washington and 42 ACRIN 6684). We used both 18F-FMISO intensity metrics (T/Bmax, HV, SUV, SUVmax, SUVpeak) and asse...

http://hdl.handle.net/10468/11085

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Positron emission tomography-based assessment of metabolic gradient and other prognostic features in sarcoma (2018)

Wolsztynski, Eric; O'Sullivan, Finbarr; Keyes, Eimear; O'Sullivan, Janet; Ear...

Positron emission tomography-based assessment of metabolic gradient and other prognostic features in sarcoma (2018)

Wolsztynski, Eric; O'Sullivan, Finbarr; Keyes, Eimear; O'Sullivan, Janet; Eary, Janet F.

Abstract:

Intratumoral heterogeneity biomarkers derived from positron emission tomography (PET) imaging with fluorodeoxyglucose (FDG) are of interest for a number of cancers, including sarcoma. A range of radiomic texture variables, adapted from general methodologies for image analysis, has shown promise in the setting. In the context of sarcoma, our group introduced an alternative model-based approach to the measurement of heterogeneity. In this approach, the heterogeneity of a tumor is characterized by the extent to which the 3-D FDG uptake pattern deviates from a simple elliptically contoured structure. By using a nonparametric analysis of the uptake profile obtained from this spatial model, a variable assessing the metabolic gradient of the tumor is developed. The work explores the prognostic potential of this new variable in the context of FDG-PET imaging of sarcoma. A mature clinical series involving 197 patients, 88 of whom have complete time-to-death information, is used. Texture vari...

http://hdl.handle.net/10468/6883

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Semi-parametric geolocation estimation in NLOS environments (2008)

Hammes, Ulrich; Wolsztynski, Eric; Zoubir, Abdelhak M.

Semi-parametric geolocation estimation in NLOS environments (2008)

Hammes, Ulrich; Wolsztynski, Eric; Zoubir, Abdelhak M.

Abstract:

The position of a stationary target can be determined using triangulation in combination with time of arrival measurements at several sensors. In urban environments, none-line-of-sight (NLOS) propagation leads to biased time estimation and thus to inaccurate position estimates. Here, a semi-parametric approach is proposed to mitigate the effects of NLOS propagation. The degree of contamination by NLOS components in the observations, which result in asymmetric noise statistics, is determined and incorporated into the estimator. The proposed method is adequate for environments where the NLOS error plays a dominant role and outperforms previous approaches that assume a symmetric noise statistic.

http://hdl.handle.net/10468/2950

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Statistical assessment of treatment response in a cancer patient based on pre-therapy and post-therapy FDG-PET scans (2016)

Wolsztynski, Eric; O'Sullivan, Finbarr; O'Sullivan, Janet; Eary, Janet F.

Statistical assessment of treatment response in a cancer patient based on pre-therapy and post-therapy FDG-PET scans (2016)

Wolsztynski, Eric; O'Sullivan, Finbarr; O'Sullivan, Janet; Eary, Janet F.

Abstract:

This work arises from consideration of sarcoma patients in which fluorodeoxyglucose positron emission tomography (FDG-PET) imaging pre-therapy and post-chemotherapy is used to assess treatment response. Our focus is on methods for evaluation of the statistical uncertainty in the measured response for an individual patient. The gamma distribution is often used to describe data with constant coefficient of variation, but it can be adapted to describe the pseudo-Poisson character of PET measurements. We propose co-registering the pre-therapy and post- therapy images and modeling the approximately paired voxel-level data using the gamma statistics. Expressions for the estimation of the treatment effect and its variability are provided. Simulation studies explore the performance in the context of testing for a treatment effect. The impact of misregistration errors and how test power is affected by estimation of variability using simplified sampling assumptions, as might be produced by di...

http://hdl.handle.net/10468/3486

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Tumor heterogeneity measurement using [18F] FDG PET/CT shows prognostic value in patients with non-small cell lung cancer (2018)

Hughes, N. M.; Mou, Tian; O'Regan, K. N.; Murphy, P.; O'Sullivan, Janet N.; W...

Tumor heterogeneity measurement using [18F] FDG PET/CT shows prognostic value in patients with non-small cell lung cancer (2018)

Hughes, N. M.; Mou, Tian; O'Regan, K. N.; Murphy, P.; O'Sullivan, Janet N.; Wolsztynski, Eric; Huang, Jian; Kennedy, Marcus P.; Eary, Janet F.; O'Sullivan, Finbarr

Abstract:

Background: The aim of this study was to evaluate primary tumor heterogeneity in patients with FDG-avid non-small cell lung cancer on PET/CT, with a view to optimising prognostic information from the metabolic signature of the primary tumor. Methods: A retrospective analysis of 94 [18F] FDG PET/CTs (56 M:38F) in patients with a diagnosis of primary lung malignancy was performed. Data collected included patient demographics, tumor size, maximum standardized uptake value (SUVmax), clinical stage and tumor histology. Clinical follow up and survival data were obtained from the available medical records. Tumor FDG spatial uptake heterogeneity was evaluated by the lack of conformity of the FDG pattern within the tumor region of interest to a simple 3-dimensional ellipsoidal form. A multivariate Cox regression analysis was used to assess the added prognostic benefit of heterogeneity information beyond radiological staging and other factors. Results: Ninety four patients (mean age 67 years,...

http://hdl.handle.net/10468/7944

Displaying Results 1 - 5 of 5 on page 1 of 1