Browsing Radiotherapy and Imaging by author "O'Connor, James Patrick"
Now showing items 1-20 of 28
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A new method for the high-precision assessment of tumor changes in response to treatment.
Tar, PD; Thacker, NA; Babur, M; Watson, Y; Cheung, S; et al. (OXFORD UNIV PRESS, 2018-08-01)MOTIVATION: Imaging demonstrates that preclinical and human tumors are heterogeneous, i.e. a single tumor can exhibit multiple regions that behave differently during both development and also in response to treatment. The ... -
A reformulation of pLSA for uncertainty estimation and hypothesis testing in bio-imaging.
Tar, PD; Thacker, NA; Deepaisarn, S; O'Connor, JPB; McMahon, AW (OXFORD UNIV PRESS, 2020-07-01)MOTIVATION: Probabilistic latent semantic analysis (pLSA) is commonly applied to describe mass spectra (MS) images. However, the method does not provide certain outputs necessary for the quantitative scientific interpretation ... -
Cancer heterogeneity and imaging.
O'Connor, JPB (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2017-04-01)There is interest in identifying and quantifying tumor heterogeneity at the genomic, tissue pathology and clinical imaging scales, as this may help better understand tumor biology and may yield useful biomarkers for guiding ... -
Clinical development of new drug-radiotherapy combinations.
Sharma, RA; Plummer, R; Stock, JK; Greenhalgh, TA; Ataman, O; et al. (NATURE PUBLISHING GROUP, 2016-10-01)In countries with the best cancer outcomes, approximately 60% of patients receive radiotherapy as part of their treatment, which is one of the most cost-effective cancer treatments. Notably, around 40% of cancer cures ... -
Data-driven mapping of hypoxia-related tumor heterogeneity using DCE-MRI and OE-MRI.
Featherstone, AK; O'Connor, JPB; Little, RA; Watson, Y; Cheung, S; et al. (WILEY, 2018-04-01)PURPOSE: Previous work has shown that combining dynamic contrast-enhanced (DCE)-MRI and oxygen-enhanced (OE)-MRI binary enhancement maps can identify tumor hypoxia. The current work proposes a novel, data-driven method for ... -
Detecting gas-induced vasomotor changes via blood oxygenation level-dependent contrast in healthy breast parenchyma and breast carcinoma.
Wallace, TE; Patterson, AJ; Abeyakoon, O; Bedair, R; Manavaki, R; et al. (WILEY-BLACKWELL, 2016-08-01)PURPOSE: To evaluate blood oxygenation level-dependent (BOLD) contrast changes in healthy breast parenchyma and breast carcinoma during administration of vasoactive gas stimuli. MATERIALS AND METHODS: Magnetic resonance ... -
Diffusion model comparison identifies distinct tumor sub-regions and tracks treatment response.
McHugh, DJ; Lipowska-Bhalla, G; Babur, M; Watson, Y; Peset, I; et al. (WILEY, 2020-09-01)PURPOSE: MRI biomarkers of tumor response to treatment are typically obtained from parameters derived from a model applied to pre-treatment and post-treatment data. However, as tumors are spatially and temporally heterogeneous, ... -
Do imaging biomarkers relate to outcome in patients treated with VEGF inhibitors?
O'Connor, JPB; Jayson, GC (AMER ASSOC CANCER RESEARCH, 2012-12-15)The management of solid tumors has been transformed by the advent of VEGF pathway inhibitors. Early clinical evaluation of these drugs has used pharmacodynamic biomarkers derived from advanced imaging such as dynamic MRI, ... -
Effect of oxaliplatin plus 5-fluorouracil or capecitabine on circulating and imaging biomarkers in patients with metastatic colorectal cancer: a prospective biomarker study.
Mahmood, RD; Shaw, D; Descamps, T; Zhou, C; Morgan, RD; et al. (BMC, 2021-04-01)BACKGROUND: Patients with metastatic colorectal cancer are treated with cytotoxic chemotherapy supplemented by molecularly targeted therapies. There is a critical need to define biomarkers that can optimise the use of these ... -
Evaluation of dynamic contrast-enhanced MRI biomarkers for stratified cancer medicine: How do permeability and perfusion vary between human tumours?
Little, RA; Barjat, H; Hare, JI; Jenner, M; Watson, Y; et al. (ELSEVIER SCIENCE INC, 2018-02-01)BACKGROUND: Solid tumours exhibit enhanced vessel permeability and fenestrated endothelium to varying degree, but it is unknown how this varies in patients between and within tumour types. Dynamic contrast-enhanced (DCE) ... -
Imaging biomarker roadmap for cancer studies.
O'Connor, JPB; Aboagye, EO; Adams, JE; Aerts, HJWL; Barrington, SF; et al. (NATURE PORTFOLIO, 2017-03-01)Imaging biomarkers (IBs) are integral to the routine management of patients with cancer. IBs used daily in oncology include clinical TNM stage, objective response and left ventricular ejection fraction. Other CT, MRI, PET ... -
Imaging tumour hypoxia with oxygen-enhanced MRI and BOLD MRI.
O'Connor, JPB; Robinson, SP; Waterton, JC (BRITISH INST RADIOLOGY, 2019-01-01)Hypoxia is known to be a poor prognostic indicator for nearly all solid tumours and also is predictive of treatment failure for radiotherapy, chemotherapy, surgery and targeted therapies. Imaging has potential to identify, ... -
Incorporating radiomics into clinical trials: expert consensus endorsed by the European Society of Radiology on considerations for data-driven compared to biologically driven quantitative biomarkers.
Fournier, L; Costaridou, L; Bidaut, L; Michoux, N; Lecouvet, FE; et al. (SPRINGER, 2021-01-25)Existing quantitative imaging biomarkers (QIBs) are associated with known biological tissue characteristics and follow a well-understood path of technical, biological and clinical validation before incorporation into ... -
Independent component analysis (ICA) applied to dynamic oxygen-enhanced MRI (OE-MRI) for robust functional lung imaging at 3 T.
Needleman, SH; Kim, M; McClelland, JR; Naish, JH; Tibiletti, M; et al. (WILEY, 2024-03-01)PURPOSE: Dynamic lung oxygen-enhanced MRI (OE-MRI) is challenging due to the presence of confounding signals and poor signal-to-noise ratio, particularly at 3 T. We have created a robust pipeline utilizing independent ... -
Is heterogeneity in stage 3 non-small cell lung cancer obscuring the potential benefits of dose-escalated concurrent chemo-radiotherapy in clinical trials?
Hudson, A; Chan, C; Woolf, D; McWilliam, A; Hiley, C; et al. (ELSEVIER IRELAND LTD, 2018-04-01)The current standard of care for the management of inoperable stage 3 non-small cell lung cancer (NSCLC) is concurrent chemoradiotherapy (cCRT) using radiotherapy dose-fractionation and chemotherapy regimens that were ... -
Mapping Hypoxia in Renal Carcinoma with Oxygen-enhanced MRI: Comparison with Intrinsic Susceptibility MRI and Pathology.
Little, RA; Jamin, Y; Boult, JKR; Naish, JH; Watson, Y; et al. (RADIOLOGICAL SOC NORTH AMERICA, 2018-09-01)Purpose To cross-validate T1-weighted oxygen-enhanced (OE) MRI measurements of tumor hypoxia with intrinsic susceptibility MRI measurements and to demonstrate the feasibility of translation of the technique for patients. ... -
Mitochondrial Inhibitor Atovaquone Increases Tumor Oxygenation and Inhibits Hypoxic Gene Expression in Patients with Non-Small Cell Lung Cancer.
Skwarski, M; McGowan, DR; Belcher, E; Di Chiara, F; Stavroulias, D; et al. (AMER ASSOC CANCER RESEARCH, 2021-05-01)PURPOSE: Tumor hypoxia fuels an aggressive tumor phenotype and confers resistance to anticancer treatments. We conducted a clinical trial to determine whether the antimalarial drug atovaquone, a known mitochondrial inhibitor, ... -
Oxygen Enhanced Optoacoustic Tomography (OE-OT) Reveals Vascular Dynamics in Murine Models of Prostate Cancer.
Tomaszewski, MR; Gonzalez, IQ; O'Connor, JP; Abeyakoon, O; Parker, GJ; et al. (IVYSPRING INT PUBL, 2017-01-01)Poor oxygenation of solid tumours has been linked with resistance to chemo- and radio-therapy and poor patient outcomes, hence non-invasive imaging of oxygen supply and demand in tumours could improve disease staging and ... -
Oxygen-Enhanced MRI Accurately Identifies, Quantifies, and Maps Tumor Hypoxia in Preclinical Cancer Models.
O'Connor, JPB; Boult, JKR; Jamin, Y; Babur, M; Finegan, KG; et al. (AMER ASSOC CANCER RESEARCH, 2015-11-19)There is a clinical need for noninvasive biomarkers of tumor hypoxia for prognostic and predictive studies, radiotherapy planning, and therapy monitoring. Oxygen-enhanced MRI (OE-MRI) is an emerging imaging technique for ... -
Oxygen-enhanced MRI Is Feasible, Repeatable, and Detects Radiotherapy-induced Change in Hypoxia in Xenograft Models and in Patients with Non-small Cell Lung Cancer.
Salem, A; Little, RA; Latif, A; Featherstone, AK; Babur, M; et al. (AMER ASSOC CANCER RESEARCH, 2019-07-01)PURPOSE: Hypoxia is associated with poor prognosis and is predictive of poor response to cancer treatments, including radiotherapy. Developing noninvasive biomarkers that both detect hypoxia prior to treatment and track ...