Paul Strickland Scanner Center

England, United Kingdom

Paul Strickland Scanner Center

England, United Kingdom
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Nathan P.D.,Mount Vernon Cancer Center | Vinayan A.,Mount Vernon Cancer Center | Stott D.,University of Hertfordshire | Juttla J.,Paul Strickland Scanner Center | Goh V.,Paul Strickland Scanner Center
Cancer Biology and Therapy | Year: 2010

Background: Response assessment is critical in evaluating effectiveness of anticancer treatment. Tyrosine kinase inhibitors (TKIs) in renal cell carcinoma (RCC) are associated with significant clinical benefit but may not result in significant tumour size reduction. Thus standard size-based response assessment with ReCIsT is insensitive, resulting in low response rates which do not reflect disease control measured by time to progression. We compared the use of combined size and density response criteria with standard size based criteria in metastatic RCC patients treated with TKI's. Results: Partial response (PR) and stable disease (SD) defined by modified criteria successfully identified patients with a long TTP (448 days) or short TTP (89 days) respectively (p = 0.002). Neither ReCIsT nor standard Choi criteria successfully discriminated between patients having a short or long clinical benefit. Patients and methods: CT scans from 32 patients with metastatic RCC treated with either sunitinib (18) or cediranib (14) were assessed. 12 patients were excluded from the analysis as 10 had non-contrast enhanced scans due to renal impairment and 2 stopped treatment due to toxicity. scans from 20 evaluable patients at baseline and 12 weeks on treatment were assessed using RECIST, Choi and modified criteria in which both a 10% decrease in size and 15% decrease in density were required to define a partial response (PR). Response assessment performed using each of the three methods was compared with time to disease progression (TTP) defined by RECIST using Kaplan-Meier statistics and Log-rank test with significance at 5%. Conclusion: a combined reduction in both size and arterial phase density of RCC metastases treated with TKIs correlates with TTP. ReCIsT and standard Choi criteria appear inferior. © 2010 Landes Bioscience.

Garcia-Figueiras R.,Complexohospitalario Universitario Of Santiago Of Compostela | Goh V.J.,King's College London | Padhani A.R.,Paul Strickland Scanner Center | Baleato-Gonzalez S.,Complexohospitalario Universitario Of Santiago Of Compostela | And 3 more authors.
American Journal of Roentgenology | Year: 2013

OBJECTIVE. This article summarizes the current status of CT perfusion in oncologic imaging, including lesion characterization, staging, prediction of patient outcome or response to therapy, assessment of response to different therapies, and evaluation of tumor relapse. Technical limitations and drawbacks of CT perfusion are also discussed. CONCLUSION. Tumor angiogenesis is essential for cancer growth and provides an attractive target for oncologic therapies. CT perfusion is an emerging imaging tool that provides both qualitative and quantitative information regarding tumor angiogenesis. © American Roentgen Ray Society.

Padhani A.R.,Paul Strickland Scanner Center | Koh D.-M.,Royal Marsden Hospital | Collins D.J.,Cancer Research UK Research Institute
Radiology | Year: 2011

Diffusion-weighted (DW) magnetic resonance (MR) imaging is emerging as a powerful clinical tool for directing the care of patients with cancer. Whole-body DW imaging is almost at the stage where it can enter widespread clinical investigations, because the technology is stable and protocols can be implemented for the majority of modern MR imaging systems. There is a continued need for further improvements in data acquisition and analysis and in display technologies. Priority areas for clinical research include clarification of histologic relationships between tissues of interest and DW MR imaging biomarkers at diagnosis and during therapy response. Because whole-body DW imaging excels at bone marrow assessments at diagnosis and for therapy response, it can potentially address a number of unmet clinical and pharmaceutical requirements. There are compelling needs to document and understand how common and novel treatments affect whole-body DW imaging results and to establish response criteria that can be tested in prospective clinical studies that incorporate measures of patient benefit. ©RSNA, 2001.

Padhani A.R.,Paul Strickland Scanner Center | Koh D.-M.,Royal Marsden Hospital
Magnetic Resonance Imaging Clinics of North America | Year: 2011

Functional imaging techniques are increasingly being used to monitor response to therapies, often predicting the success of therapy before conventional measurements are changed. This review focuses on magnetic resonance imaging (MRI) depicted water diffusivity as a tumor response parameter. Response assessments are undertaken by noting changes in signal intensity on high b-value images or by using measurements of apparent diffusion coefficient values. The different diffusion-weighted (DW)-MRI appearances in response to treatment of soft tissue disease and bone metastases are discussed. DW-MRI changes observed in response to cytotoxics, radiotherapy, antiangiogenics, embolization, and thermocoagulation are detailed. © 2011 Elsevier Inc.

Koh D.-M.,Royal Marsden Hospital | Blackledge M.,Institute of Cancer Research | Padhani A.R.,Paul Strickland Scanner Center | Takahara T.,Tokai University | And 3 more authors.
American Journal of Roentgenology | Year: 2012

OBJECTIVE. We examine the clinical impetus for whole-body diffusion-weighted MRI and discuss how to implement the technique with clinical MRI systems. We include practical tips and tricks to optimize image quality and reduce artifacts. The interpretative pitfalls are enumerated, and potential challenges are highlighted. CONCLUSION. Whole-body diffusion-weighted MRI can be used for tumor staging and assessment of treatment response. Meticulous technique and knowledge of potential interpretive pitfalls will help to avoid mistakes and establish this modality in radiologic practice. © American Roentgen Ray Society.

Khoo M.M.Y.,Royal National Orthopaedic Hospital | Tyler P.A.,Royal National Orthopaedic Hospital | Saifuddin A.,Royal National Orthopaedic Hospital | Padhani A.R.,Paul Strickland Scanner Center
Skeletal Radiology | Year: 2011

Magnetic resonance imaging (MRI) is the mainstay of diagnosis, staging and follow-up of much musculoskeletal pathology. Diffusion-weighted magnetic resonance imaging (DWI) is a recent addition to the MR sequences conventionally employed. DWI provides qualitative and quantitative functional information concerning the microscopic movements of water at the cellular level. A number of musculoskeletal disorders have been evaluated by DWI, including vertebral fractures, bone marrow infection, bone marrow malignancy, primary bone and soft tissue tumours; post-treatment follow-up has also been assessed. Differentiation between benign and malignant vertebral fractures by DWI and monitoring of therapy response have shown excellent results. However, in other pathologies, such as primary soft tissue tumours, DWI data have been inconclusive in some cases, contributing little additional information beyond that gained from conventional MR sequences. The aim of this article is to critically review the current literature on the contribution of DWI to musculoskeletal MRI. © 2011 ISS.

Rosenkrantz A.B.,NYU Langone Medical Center | Padhani A.R.,Paul Strickland Scanner Center | Chenevert T.L.,University of Michigan | Koh D.-M.,Royal Marsden NHS Foundation Trust | And 3 more authors.
Journal of Magnetic Resonance Imaging | Year: 2015

Technologic advances enable performance of diffusion-weighted imaging (DWI) at ultrahigh b-values, where standard monoexponential model analysis may not apply. Rather, non-Gaussian water diffusion properties emerge, which in cellular tissues are, in part, influenced by the intracellular environment that is not well evaluated by conventional DWI. The novel technique, diffusion kurtosis imaging (DKI), enables characterization of non-Gaussian water diffusion behavior. More advanced mathematical curve fitting of the signal intensity decay curve using the DKI model provides an additional parameter Kapp that presumably reflects heterogeneity and irregularity of cellular microstructure, as well as the amount of interfaces within cellular tissues. Although largely applied for neural applications over the past decade, a small number of studies have recently explored DKI outside the brain. The most investigated organ is the prostate, with preliminary studies suggesting improved tumor detection and grading using DKI. Although still largely in the research phase, DKI is being explored in wider clinical settings. When assessing extracranial applications of DKI, careful attention to details with which body radiologists may currently be unfamiliar is important to ensure reliable results. Accordingly, a robust understanding of DKI is necessary for radiologists to better understand the meaning of DKI-derived metrics in the context of different tumors and how these metrics vary between tumor types and in response to treatment. In this review, we outline DKI principles, propose biostructural basis for observations, provide a comparison with standard monoexponential fitting and the apparent diffusion coefficient, report on extracranial clinical investigations to date, and recommend technical considerations for implementation in body imaging. © 2015 Wiley Periodicals, Inc.

Padhani A.R.,Paul Strickland Scanner Center | Gogbashian A.,Paul Strickland Scanner Center
Cancer Imaging | Year: 2011

There are no universally accepted methods for assessing tumour response in skeletal sites with metastatic disease; response is assessed by a combination of imaging tests, serum and urine biochemical markers and symptoms assessments. Whole-body diffusion magnetic resonance imaging excels at bone marrow assessments at diagnosis and for therapy evaluations. It can potentially address unmet clinical and pharmaceutical needs for a reliable measure of tumour response. Signal intensity on high b-value images and apparent diffusion coefficient values can be related to underlying biophysical properties of skeletal metastases. Four patterns of change in response to therapy are described this review. Therapy response criteria need to be tested in prospective clinical studies that incorporate conventional measures of patient benefit. © 2009 International Cancer Imaging Society.

Padhani A.R.,Paul Strickland Scanner Center | Collins D.J.,Cancer Research UK Research Institute | D'Sa S.,Mount Vernon Cancer Center | Makris A.,Academic Oncology Unit
American Journal of Roentgenology | Year: 2013

OBJECTIVE. The purposes of this study were to observe the relation between signal intensity (SI) on MR images with a high b value and the apparent diffusion coefficient (ADC) of bone marrow on body diffusion-weighted MR images, to determine cutoff values that enable separation of malignant and normal bone marrow, and to identify the upper ADC values of untreated multiple myeloma lesions and bone metastatic lesions of breast cancer. MATERIALS AND METHODS. Retrospective evaluations of 16 patients without bone disease, 21 patients with untreated metastases of breast cancer, and 12 patients with myeloma undergoing body diffusion-weighted MRI were performed (b values, 50 s/mm2 and 800 or 900 s/mm2). Normal yellow and red bone marrow regions were compared with metastatic breast and myeloma bone marrow lesions (one to five regions of interest per patient). SI values were normalized to kidney, muscle, and spinal cord SI. Signal-to-noise ratio and ADC for each lesion were recorded. Nonparametric, receiver operating characteristic, and nonlinear regression analyses were performed. RESULTS. Yellow bone marrow and red bone marrow ADC values were lower than the tumor values (p < 0.001; area under the curve, 0.94; cutoff, 774 μm2/s). Tissue-normalized SI and the signal-to-noise ratio of normal bone marrow were also lower than those in tumor regions (p < 0.001; area under the curve, 0.86-0.88). Second-order polynomial curve fitting between SI and ADC was observed (muscle normalized SI, R 2 = 0.4). The 95th percentile and maximum values for mean tumor ADC distribution were 1209 μm2/s and 1433 μm2/s. CONCLUSION. Both tissue-normalized SI and ADC measurements allow differentiation between normal bone marrow and tumors of myeloma and breast cancer. The presence of a nonlinear relation between bone marrow SI and ADC values enables definition of an upper limit of ADC value for untreated myeloma lesions and metastatic lesions of breast cancer. © American Roentgen Ray Society.

Padhani A.R.,Paul Strickland Scanner Center
Cancer Imaging | Year: 2011

Multifunctional magnetic resonance imaging (MRI) techniques are increasingly being used to address bottlenecks in prostate cancer patient management. These techniques yield qualitative, semi-quantitative and fully quantitative biomarkers that reflect on the underlying biological status of a tumour. If these techniques are to have a role in patient management, then standard methods of data acquisition, analysis and reporting have to be developed. Effective communication by the use of scoring systems, structured reporting and a graphical interface that matches prostate anatomy are key elements. Practical guidelines for integrating multiparametric MRI into clinical practice are presented. © 2009 International Cancer Imaging Society.

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