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David S, Visvikis D, Quellec G, Le Rest CC, Fernandez P, Allard M, Roux C, Hatt M. Image change detection using paradoxical theory for patient follow-up quantitation and therapy assessment. IEEE TRANSACTIONS ON MEDICAL IMAGING 2012; 31:1743-1753. [PMID: 22614573 DOI: 10.1109/tmi.2012.2199511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In clinical oncology, positron emission tomography (PET) imaging can be used to assess therapeutic response by quantifying the evolution of semi-quantitative values such as standardized uptake value, early during treatment or after treatment. Current guidelines do not include metabolically active tumor volume (MATV) measurements and derived parameters such as total lesion glycolysis (TLG) to characterize the response to the treatment. To achieve automatic MATV variation estimation during treatment, we propose an approach based on the change detection principle using the recent paradoxical theory, which models imprecision, uncertainty, and conflict between sources. It was applied here simultaneously to pre- and post-treatment PET scans. The proposed method was applied to both simulated and clinical datasets, and its performance was compared to adaptive thresholding applied separately on pre- and post-treatment PET scans. On simulated datasets, the adaptive threshold was associated with significantly higher classification errors than the developed approach. On clinical datasets, the proposed method led to results more consistent with the known partial responder status of these patients. The method requires accurate rigid registration of both scans which can be obtained only in specific body regions and does not explicitly model uptake heterogeneity. In further investigations, the change detection of intra-MATV tracer uptake heterogeneity will be developed by incorporating textural features into the proposed approach.
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Affiliation(s)
- Simon David
- LaTIM, INSERM, UMR1101, 29609 Brest, France. david.simon@ univ-brest.fr
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252
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Van Beers BE, Doblas S, Sinkus R. New acquisition techniques: fields of application. ACTA ACUST UNITED AC 2012; 37:155-63. [PMID: 21584637 DOI: 10.1007/s00261-011-9748-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Conventional MR imaging of the liver has a central role in the assessment of liver diseases. Diffusion-weighted MR imaging, MR elastography, and time-resolved dynamic contrast-enhanced MR imaging improve the anatomical information provided by conventional MR imaging and add quantitative functional information in diffuse and focal liver diseases. Particularly, accurate detection and characterization of liver fibrosis are feasible with quantitative MR elastography, detection of liver tumors is increased with diffusion-weighted MR imaging and time-resolved dynamic contrast-enhanced MR imaging, characterization of tumors can be improved with quantitative diffusion-weighted MR imaging and MR elastography. These methods also have the potential to provide adequate biomarkers for assessing the response to treatment. Currently, the main limitations of quantitative MR imaging are related to reproducibility, standardization, and/or limited clinical data. It is important to improve and standardize the quantitative MR methods and validate their role in large multicenter trials.
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Affiliation(s)
- Bernard E Van Beers
- Department of Radiology and IPMA, INSERM UMR773, Beaujon University Hospital, University of Paris Diderot, 100 Avenue du General Leclerc, 92110, Clichy, France.
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253
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Hayes LL, Jones RA, Palasis S, Aguilera D, Porter DA. Drop metastases to the pediatric spine revealed with diffusion-weighted MR imaging. Pediatr Radiol 2012; 42:1009-13. [PMID: 22052343 DOI: 10.1007/s00247-011-2295-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 10/05/2011] [Accepted: 10/07/2011] [Indexed: 01/17/2023]
Abstract
Identifying drop metastases to the spine from pediatric brain tumors is crucial to treatment and prognosis. MRI is currently the gold standard for identifying drop metastases, more sensitive than CSF cytology, but imaging is not uncommonly inconclusive. Although diffusion-weighted imaging (DWI) of the brain is very useful in the evaluation of hypercellular tumors, DWI of the spine has not been clinically useful in children because of susceptibility artifacts and lack of spatial resolution. A new technique, readout-segmented echo planar imaging (EPI), has improved these images, allowing for identification of hypercellular drop metastases. We report a case that illustrates the utility of spine DWI in the detection of metastatic disease in children with primary central nervous system (CNS) tumors. This case suggests that DWI of the spine with readout-segmented EPI should be included in the evaluation for drop metastases.
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Affiliation(s)
- Laura L Hayes
- Department of Radiology, Children's Healthcare of Atlanta at Scottish Rite, 1001 Johnson Ferry Road NE, Atlanta, GA 30342, USA.
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254
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Nilsson M, Lätt J, van Westen D, Brockstedt S, Lasič S, Ståhlberg F, Topgaard D. Noninvasive mapping of water diffusional exchange in the human brain using filter-exchange imaging. Magn Reson Med 2012; 69:1573-81. [PMID: 22837019 DOI: 10.1002/mrm.24395] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 05/22/2012] [Accepted: 06/05/2012] [Indexed: 12/20/2022]
Abstract
We present the first in vivo application of the filter-exchange imaging protocol for diffusion MRI. The protocol allows noninvasive mapping of the rate of water exchange between microenvironments with different self-diffusivities, such as the intracellular and extracellular spaces in tissue. Since diffusional water exchange across the cell membrane is a fundamental process in human physiology and pathophysiology, clinically feasible and noninvasive imaging of the water exchange rate would offer new means to diagnose disease and monitor treatment response in conditions such as cancer and edema. The in vivo use of filter-exchange imaging was demonstrated by studying the brain of five healthy volunteers and one intracranial tumor (meningioma). Apparent exchange rates in white matter range from 0.8±0.08 s(-1) in the internal capsule, to 1.6±0.11 s(-1) for frontal white matter, indicating that low values are associated with high myelination. Solid tumor displayed values of up to 2.9±0.8 s(-1). In white matter, the apparent exchange rate values suggest intra-axonal exchange times in the order of seconds, confirming the slow exchange assumption in the analysis of diffusion MRI data. We propose that filter-exchange imaging could be used clinically to map the water exchange rate in pathologies. Filter-exchange imaging may also be valuable for evaluating novel therapies targeting the function of aquaporins.
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Affiliation(s)
- Markus Nilsson
- Department of Medical Radiation Physics, Lund University, Lund, Sweden.
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255
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Characterizing tumor response to chemotherapy at various length scales using temporal diffusion spectroscopy. PLoS One 2012; 7:e41714. [PMID: 22911846 PMCID: PMC3404000 DOI: 10.1371/journal.pone.0041714] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/26/2012] [Indexed: 01/22/2023] Open
Abstract
Measurements of apparent diffusion coefficient (ADC) using magnetic resonance imaging (MRI) have been suggested as potential imaging biomarkers for monitoring tumor response to treatment. However, conventional pulsed-gradient spin echo (PGSE) methods incorporate relatively long diffusion times, and are usually sensitive to changes in cell density and necrosis. Diffusion temporal spectroscopy using the oscillating gradient spin echo (OGSE) sequence is capable of probing short length scales, and may detect significant intracellular microstructural changes independent of gross cell density changes following anti-cancer treatment. To test this hypothesis, SW620 xenografts were treated by barasertib (AZD1152), a selective inhibitor of Aurora B kinase which causes SW620 cancer cells to develop polyploidy and increase in size following treatment, ultimately leading to cell death through apoptosis. Following treatment, the ADC values obtained by both the PGSE and low frequency OGSE methods increased. However, the ADC values at high gradient frequency (i.e. short diffusion times) were significantly lower in treated tumors, consistent with increased intracellular restrictions/hindrances. This suggests that ADC values at long diffusion times are dominated by tumor microstructure at long length scales, and may not convey unambiguous information of subcellular space. While the diffusion temporal spectroscopy provides more comprehensive means to probe tumor microstructure at various length scales. This work is the first study to probe intracellular microstructural variations due to polyploidy following treatment using diffusion MRI in vivo. It is also the first observation of post-treatment ADC changes occurring in opposite directions at short and long diffusion times. The current study suggests that temporal diffusion spectroscopy potentially provides pharmacodynamic biomarkers of tumor early response which distinguish microstructural variations following treatment at both the subcellular and supracellular length scales.
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256
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James ML, Gambhir SS. A molecular imaging primer: modalities, imaging agents, and applications. Physiol Rev 2012; 92:897-965. [PMID: 22535898 DOI: 10.1152/physrev.00049.2010] [Citation(s) in RCA: 702] [Impact Index Per Article: 58.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Molecular imaging is revolutionizing the way we study the inner workings of the human body, diagnose diseases, approach drug design, and assess therapies. The field as a whole is making possible the visualization of complex biochemical processes involved in normal physiology and disease states, in real time, in living cells, tissues, and intact subjects. In this review, we focus specifically on molecular imaging of intact living subjects. We provide a basic primer for those who are new to molecular imaging, and a resource for those involved in the field. We begin by describing classical molecular imaging techniques together with their key strengths and limitations, after which we introduce some of the latest emerging imaging modalities. We provide an overview of the main classes of molecular imaging agents (i.e., small molecules, peptides, aptamers, engineered proteins, and nanoparticles) and cite examples of how molecular imaging is being applied in oncology, neuroscience, cardiology, gene therapy, cell tracking, and theranostics (therapy combined with diagnostics). A step-by-step guide to answering biological and/or clinical questions using the tools of molecular imaging is also provided. We conclude by discussing the grand challenges of the field, its future directions, and enormous potential for further impacting how we approach research and medicine.
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Affiliation(s)
- Michelle L James
- Molecular Imaging Program, Department of Radiology, Stanford University, Palo Alto, CA 94305, USA
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257
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Hoff BA, Kozloff KM, Boes JL, Brisset JC, Galbán S, Van Poznak CH, Jacobson JA, Johnson TD, Meyer CR, Rehemtulla A, Ross BD, Galbán CJ. Parametric response mapping of CT images provides early detection of local bone loss in a rat model of osteoporosis. Bone 2012; 51:78-84. [PMID: 22542461 PMCID: PMC3371150 DOI: 10.1016/j.bone.2012.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 03/09/2012] [Accepted: 04/09/2012] [Indexed: 01/18/2023]
Abstract
Loss of bone mass due to disease, such as osteoporosis and metastatic cancer to the bone, is a leading cause of orthopedic complications and hospitalization. Onset of bone loss resulting from disease increases the risk of incurring fractures and subsequent pain, increasing medical expenses while reducing quality of life. Although current standard CT-based protocols provide adequate prognostic information for assessing bone loss, many of the techniques for evaluating CT scans rely on measures based on whole-bone summary statistics. This reduces the sensitivity at identifying local regions of bone resorption, as well as formation. In this study, we evaluate the effectiveness of a voxel-based image post-processing technique, called the Parametric Response Map (PRM), for identifying local changes in bone mass in weight-bearing bones on CT scans using an established animal model of osteoporosis. Serial CT scans were evaluated weekly using PRM subsequent to ovariectomy or sham surgeries over the period of one month. For comparison, bone volume fraction and mineral density measurements were acquired and found to significantly differ between groups starting 3 weeks post-surgery. High resolution ex vivo measurements acquired four weeks post-surgery validated the extent of bone loss in the surgical groups. In contrast to standard methodologies for assessing bone loss, PRM results were capable of identifying local decreases in bone mineral by week 2, which were found to be significant between groups. This study concludes that PRM is able to detect changes in bone mineral with higher sensitivity and spatial differentiation than conventional techniques for evaluating CT scans, which may aid in clinical decision making for patients suffering from bone loss.
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Affiliation(s)
- Benjamin A. Hoff
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Kenneth M. Kozloff
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Jennifer L. Boes
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | | | - Stefanie Galbán
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | | | - Jon A. Jacobson
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Timothy D. Johnson
- Department of Biostatistics, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Charles R. Meyer
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Alnawaz Rehemtulla
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Brian D. Ross
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Craig J. Galbán
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, 48109, USA
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258
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Allen AM, Ben-Ami M, Reshef A, Steinmetz A, Kundel Y, Inbar E, Djaldetti R, Davidson T, Fenig E, Ziv I. Assessment of response of brain metastases to radiotherapy by PET imaging of apoptosis with ¹⁸F-ML-10. Eur J Nucl Med Mol Imaging 2012; 39:1400-8. [PMID: 22699524 DOI: 10.1007/s00259-012-2150-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 04/30/2012] [Indexed: 01/01/2023]
Abstract
PURPOSE Early assessment of tumor response to therapy is vital for treatment optimization for the individual cancer patient. Induction of apoptosis is an early and nearly universal effect of anticancer therapies. The purpose of this study was to assess the performance of (18)F-ML-10, a novel PET radiotracer for apoptosis, as a tool for the early detection of response of brain metastases to whole-brain radiation therapy (WBRT). MATERIALS AND METHODS Ten patients with brain metastases treated with WBRT at 30 Gy in ten daily fractions were enrolled in this trial. Each patient underwent two (18)F-ML-10 PET scans, one prior to the radiation therapy (baseline scan), and the second after nine or ten fractions of radiotherapy (follow-up scan). MRI was performed at 6-8 weeks following completion of the radiation therapy. Early treatment-induced changes in tumor (18)F-ML-10 uptake on the PET scan were measured by voxel-based analysis, and were then evaluated by correlation analysis as predictors of the extent of later changes in tumor anatomical dimensions as seen on MRI scans 6-8 weeks after completion of therapy. RESULTS In all ten patients, all brain lesions were detected by both MRI and the (18)F-ML-10 PET scan. A highly significant correlation was found between early changes on the (18)F-ML-10 scan and later changes in tumor anatomical dimensions (r = 0.9). CONCLUSION These results support the potential of (18)F-ML-10 PET as a novel tool for the early detection of response of brain metastases to WBRT.
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Affiliation(s)
- Aaron M Allen
- Department of Radiation Oncology, Nuclear Medicine, Radiology and Neurology, Rabin Medical Center, Petach-Tikvah, Israel.
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259
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Brindle K. Watching tumours gasp and die with MRI: the promise of hyperpolarised 13C MR spectroscopic imaging. Br J Radiol 2012; 85:697-708. [PMID: 22496072 PMCID: PMC3474112 DOI: 10.1259/bjr/81120511] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 01/03/2012] [Accepted: 01/05/2012] [Indexed: 12/31/2022] Open
Abstract
A better understanding of tumour biology has led to the development of "targeted therapies", in which a drug is designed to disrupt a specific biochemical pathway important for tumour cell survival or proliferation. The introduction of these drugs into the clinic has shown that patients can vary widely in their responses. Molecular imaging is likely to play an increasingly important role in predicting and detecting these responses and thus in guiding treatment in individual patients: so-called "personalised medicine". The aim of this review is to discuss how hyperpolarised (13)C MR spectroscopic imaging might be used for treatment response monitoring. This technique, which increases the sensitivity of detection of injected (13)C-labelled molecules by >10,000-fold, has allowed a new approach to metabolic imaging. The basic principles of the technique and its potential advantages over other imaging methods for detecting early evidence of treatment response will be discussed. Given that the technique is poised to translate to the clinic, I will also speculate on its likely applications.
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Affiliation(s)
- K Brindle
- Department of Biochemistry, University of Cambridge, Cambridge, UK.
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260
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Early diffusion weighted magnetic resonance imaging can predict survival in women with locally advanced cancer of the cervix treated with combined chemo-radiation. Eur Radiol 2012; 22:2319-27. [DOI: 10.1007/s00330-012-2496-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Accepted: 04/06/2012] [Indexed: 01/17/2023]
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261
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Halappa VG, Bonekamp S, Corona-Villalobos CP, Li Z, Mensa M, Reyes D, Eng J, Bhagat N, Pawlik TM, Geschwind JF, Kamel IR. Intrahepatic cholangiocarcinoma treated with local-regional therapy: quantitative volumetric apparent diffusion coefficient maps for assessment of tumor response. Radiology 2012; 264:285-94. [PMID: 22627601 DOI: 10.1148/radiol.12112142] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE To evaluate volumetric changes in apparent diffusion coefficient (ADC) and contrast material enhancement on contrast-enhanced (CE) magnetic resonance (MR) images in hepatic arterial and portal venous phases for assessing early response in cholangiocarcinoma treated with transcatheter arterial chemoembolization (TACE). MATERIALS AND METHODS Twenty-nine patients with unresectable cholangiocarcinoma, including 11 men (mean age, 60 years; standard deviation, 16.8) and 18 women (mean age, 63 years; standard deviation, 11.5) were included in this retrospective institutional review board-approved, HIPAA-compliant study; informed consent was waived. Sixty-nine TACE procedures were performed during the observational time (range, one to five TACE sessions). No patients received another form of therapy after treatment with TACE. MR Imaging was performed before and 3-4 weeks after TACE, and images were analyzed with a semiautomatic volumetric software package. Patients were stratified as responders and nonresponders on the basis of overall survival (OS) as the primary end point. Differences between responders and nonresponders were analyzed with paired t tests, and OS was calculated with the Kaplan-Meier method. Significant differences were analyzed with the log-rank test. RESULTS Mean volumetric ADC increased from 1.54×10(-3) mm2/sec to 1.92×10(-3) mm2/sec (P<.0001), with no significant decrease in mean volumetric enhancement in hepatic arterial (40.6% vs 37.5%, P=.546) and portal venous (79.0% vs 70.0%, P=.105) phases. Patients who demonstrated improved survival of 10 months or more had a significant increase in mean volumetric ADC and volumetric ADC above the threshold level of 1.60×10(-3) mm2/sec (P<.002). Patients with 45% or greater (n=21; log-rank test, P<.02) and 60% or greater (n=12; log-rank test, P<.009) ADC changes for the whole tumor volume demonstrated better OS compared with patients in whom these ADC changes were not achieved. CONCLUSION Patients with percentage tumor volume increase in ADC of 45% or greater and 60% or greater above the threshold level of 1.60×10(-3) mm2/sec had favorable response to therapy and improved survival.
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Affiliation(s)
- Vivek Gowdra Halappa
- Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, 600 N Wolfe St, Room 143, Baltimore, MD 21287, USA
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262
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Savolainen S, Kortesniemi M, Timonen M, Reijonen V, Kuusela L, Uusi-Simola J, Salli E, Koivunoro H, Seppälä T, Lönnroth N, Välimäki P, Hyvönen H, Kotiluoto P, Serén T, Kuronen A, Heikkinen S, Kosunen A, Auterinen I. Boron neutron capture therapy (BNCT) in Finland: technological and physical prospects after 20 years of experiences. Phys Med 2012; 29:233-48. [PMID: 22613369 DOI: 10.1016/j.ejmp.2012.04.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 04/17/2012] [Accepted: 04/24/2012] [Indexed: 01/18/2023] Open
Abstract
Boron Neutron Capture Therapy (BNCT) is a binary radiotherapy method developed to treat patients with certain malignant tumours. To date, over 300 treatments have been carried out at the Finnish BNCT facility in various on-going and past clinical trials. In this technical review, we discuss our research work in the field of medical physics to form the groundwork for the Finnish BNCT patient treatments, as well as the possibilities to further develop and optimize the method in the future. Accordingly, the following aspects are described: neutron sources, beam dosimetry, treatment planning, boron imaging and determination, and finally the possibilities to detect the efficacy and effects of BNCT on patients.
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263
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Reischauer C, Gutzeit A, Vorburger RS, Froehlich JM, Binkert CA, Boesiger P. Optimizing the functional diffusion map using Monte Carlo simulations. J Magn Reson Imaging 2012; 36:1002-9. [PMID: 22550013 DOI: 10.1002/jmri.23690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/30/2012] [Indexed: 01/17/2023] Open
Abstract
PURPOSE To optimize the diagnostic accuracy of the functional diffusion map for monitoring tumor treatment response in cancer patients. MATERIALS AND METHODS Using Monte Carlo simulations, measurement precision of the apparent diffusion coefficient (ADC), and particularly accuracy of threshold determination from healthy reference tissue, are evaluated by investigating the repeatability limit of the ADC as a function of different degrees of diffusion weighting of the sequence. Phantom and in-vivo experiments are performed to verify and illustrate the results of the simulations. RESULTS While diagnostic accuracy of the functional diffusion map is hardly diminished by differing values of the T(2) relaxation time in tumor and reference tissue, it is shown to be impaired by differing ADCs, resulting in erroneously determined segmentation thresholds. This problem can be addressed by decreasing the maximum b-factor and increasing the number of signal averages at the maximum b-factor or, alternatively, the number of b-factors while favoring schemes with higher b-factors. Phantom experiments confirm the results of the simulations. In-vivo data are presented to illustrate the effect of sequence optimization on the diagnostic accuracy of the functional diffusion map. CONCLUSION The present work demonstrates that the diagnostic accuracy of the functional diffusion map can be impaired by inaccurate segmentation thresholds and derives means for its optimization that will increase the fidelity of future clinical studies.
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Affiliation(s)
- Carolin Reischauer
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.
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264
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Paldino MJ, Desjardins A, Friedman HS, Vredenburgh JJ, Barboriak DP. A change in the apparent diffusion coefficient after treatment with bevacizumab is associated with decreased survival in patients with recurrent glioblastoma multiforme. Br J Radiol 2012; 85:382-9. [PMID: 21224297 PMCID: PMC3486655 DOI: 10.1259/bjr/24774491] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 06/09/2010] [Accepted: 06/22/2010] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVES The aim of this study was to determine the prognostic significance of changes in parameters derived from diffusion tensor imaging (DTI) that occur in response to treatment with bevacizumab and irinotecan in patients with recurrent glioblastoma multiforme. METHODS 15 patients with recurrent glioblastoma multiforme underwent serial 1.5 T MRI. Axial single-shot echo planar DTI was obtained on scans performed 3 days and 1 day prior to and 6 weeks after initiation of therapy with bevacizumab and irinotecan. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps were registered to whole brain contrast-enhanced three-dimensional (3D) spoiled gradient recalled and 3D fluid attenuation inversion recovery (FLAIR) image volumes. Anatomic image volumes were segmented to isolate regions of interest defined by tumour-related enhancement (TRE) and FLAIR signal abnormality (FSA). Mean ADC and mean FA were calculated for each region. A Bland-Altman repeatability coefficient was also calculated for each parameter based on the two pre-treatment studies. A patient was considered to have a change in FA or ADC after therapy if the difference between the pre- and post-treatment values was greater than the repeatability coefficient for that parameter. Survival was compared using a Cox proportional hazard model. RESULTS DTI detected a change in ADC within FSA after therapy in nine patients (five in whom ADC was increased; four in whom it was decreased). Patients with a change in ADC within FSA had significantly shorter overall survival (p=0.032) and progression free survival (p=0.046) than those with no change. CONCLUSION In patients with recurrent glioblastoma multiforme treated with bevacizumab and irinotecan, a change in ADC after therapy in FSA is associated with decreased survival.
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Affiliation(s)
- M J Paldino
- Department of Radiology, Duke University Medical Center, Durham, NC, USA.
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265
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Abstract
Head and neck imaging has benefited from 1.5 T magnetic resonance (MR) imaging, providing faster sequences, better soft tissue evaluation, and 3-axis imaging, with less radiation and iodine-based contrast injection. The US Food and Drug Administration has approved human MR imaging at high-field strength up to 4 T in clinical practice. 3 T MR imaging has become widely available, with the hope of significant advance in the evaluation of the head and neck region. This article reviews the benefits, disadvantages, and challenges of high-field imaging of the head and neck region, focusing on the imaging of head and neck cancer.
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266
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Martincich L, Deantoni V, Bertotto I, Redana S, Kubatzki F, Sarotto I, Rossi V, Liotti M, Ponzone R, Aglietta M, Regge D, Montemurro F. Correlations between diffusion-weighted imaging and breast cancer biomarkers. Eur Radiol 2012; 22:1519-28. [PMID: 22411304 DOI: 10.1007/s00330-012-2403-8] [Citation(s) in RCA: 171] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 12/17/2011] [Accepted: 12/21/2011] [Indexed: 12/15/2022]
Abstract
OBJECTIVE We evaluated whether the apparent diffusion coefficient (ADC) provided by diffusion-weighted imaging (DWI) varies according to biological features in breast cancer. METHODS DWI was performed in 190 patients undergoing dynamic contrast-enhanced magnetic resonance imaging (MRI) for local staging. For each of the 192 index cancers we studied the correlation between ADC and classical histopathological and immunohistochemical breast tumour features (size, histological type, grade, oestrogen receptor [ER] and Ki-67 expression, HER2 status). ADC was compared with immunohistochemical surrogates of the intrinsic subtypes (Luminal A; Luminal B; HER2-enriched; triple-negative). Correlations were analysed using the Mann-Whitney U and Kruskal-Wallis H tests. RESULTS A weak, statistically significant correlation was observed between ADC values and the percentage of ER-positive cells (-0.168, P = 0.020). Median ADC values were significantly higher in ER-negative than in ER-positive tumours (1.110 vs 1.050 × 10(-3) mm(2)/s, P = 0.015). HER2-enriched tumours had the highest median ADC value (1.190 × 10(-3) mm(2)/s, range 0.950-2.090). Multiple comparisons showed that this value was significantly higher than that of Luminal A (1.025 × 10(-3) mm(2)/s [0.700-1.340], P = 0.004) and Luminal B/HER2-negative (1.060 × 10(-3) mm(2)/s [0.470-2.420], P = 0.008) tumours. A trend towards statistical significance (P = 0.018) was seen with Luminal B/HER2-positive tumours. CONCLUSIONS ADC values vary significantly according to biological tumour features, suggesting that cancer heterogeneity influences imaging parameters. KEY POINTS DWI may identify biological heterogeneity of breast neoplasms. • ADC values vary significantly according to biological features of breast cancer. • Compared with other types, HER2-enriched tumours show highest median ADC value. • Knowledge of biological heterogeneity of breast neoplasm may improve imaging interpretation.
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Affiliation(s)
- Laura Martincich
- Unit of Radiology, Institute for Cancer Research and Treatment (IRCC), Strada Provinciale 142, 10060, Candiolo, Turin, Italy.
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267
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Statistical power in quantitative diffusion MRI of tumor response: strategies for future studies. Acad Radiol 2012; 19:326-30. [PMID: 22177972 DOI: 10.1016/j.acra.2011.10.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 10/11/2011] [Accepted: 10/12/2011] [Indexed: 01/18/2023]
Abstract
RATIONALE AND OBJECTIVES Diffusion magnetic resonance imaging may be useful in tracking tumor growth and response to treatment. However, studies using these measures may lack statistical power to draw definitive conclusions regarding changes in tumor cellularity. Using apparent diffusion coefficient values taken from the literature, the investigators estimated sample sizes for a range of changes to the mean. MATERIALS AND METHODS A literature search was performed of studies measuring the average apparent diffusion coefficients for various bodily tissues, and the mean and standard deviation from each study were recorded. Analyses of statistical power were then performed using these values and comparing them to a population of healthy controls. RESULTS Tumor cellularity as measured by apparent diffusion coefficients may have high sensitivity, but the analyses indicate that investigations in this field may potentially suffer from low statistical power. For example, the findings indicate that samples of <20 patients may require a mean change of approximately 25% between study conditions. CONCLUSIONS Suggestions are offered for improvements in methodologic approaches and in data reporting to assist in overcoming the limitations of small sample sizes. On the basis of this literature review, reference values are provided to help investigators estimate study sample size to achieve adequate statistical power.
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268
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Advances in ultra-high field MRI for the clinical management of patients with brain tumors. Curr Opin Neurol 2012; 24:605-15. [PMID: 22045220 DOI: 10.1097/wco.0b013e32834cd495] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
PURPOSE OF REVIEW The last 5 years have seen the number of ultra-high field (UHF; 7 T and beyond) MRI scanners nearly double. Benefits include improved specificity, better sensitivity for signal-starved compounds, and the ability to detect, quantify, and monitor tumor activity and treatment effects. This is especially important in the current climate in which new treatments alter established markers of tumor and the surrounding environment, confounding traditional response criteria. RECENT FINDINGS Intra-tumoral heterogeneity and dramatic improvement in spatial localization have been observed with 7 and 8 T high-resolution T2-weighted and T2*-weighted imaging. This depiction of lesions that were not readily detected at lower field improved the classification of glioma. Sub-millimeter visualization of microvasculature has facilitated the detection of microbleeds associated with long-term effects of radiation. New metabolic markers seen at UHF may also assist in distinguishing tumor progression from treatment effect. SUMMARY Although progress has been limited by technical challenges, initial experience has demonstrated the promise of 7-T MRI in advancing existing paradigms for diagnosing, monitoring, and managing patients with brain tumors. The success of these systems will depend upon what new information can be gained by UHF, rather than simply improving the quality of the current lower field standard.
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269
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Pan J, Zang L, Zhang Y, Hong J, Yao Y, Zou C, Zhang L, Chen Y. Early changes in apparent diffusion coefficients predict radiosensitivity of human nasopharyngeal carcinoma xenografts. Laryngoscope 2012; 122:839-43. [DOI: 10.1002/lary.23208] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 12/17/2011] [Accepted: 12/22/2011] [Indexed: 01/17/2023]
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Abstract
This article aims to provide an educational document of magnetic resonance imaging principles for applied biomedical users of the technology. Basic principles are illustrated using simple experimental models on a preclinical imaging system.
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Affiliation(s)
- W D Foltz
- STTARR Innovation Centre, Department of Radiation Oncology, Princess Margaret Hospital, Toronto, Ontario, Canada.
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271
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Russell G, Harkins KD, Secomb TW, Galons JP, Trouard TP. A finite difference method with periodic boundary conditions for simulations of diffusion-weighted magnetic resonance experiments in tissue. Phys Med Biol 2012; 57:N35-46. [PMID: 22297418 DOI: 10.1088/0031-9155/57/4/n35] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A new finite difference (FD) method for calculating the time evolution of complex transverse magnetization in diffusion-weighted magnetic resonance imaging and spectroscopy experiments is described that incorporates periodic boundary conditions. The new FD method relaxes restrictions on the allowable time step size employed in modeling which can significantly reduce computation time for simulations of large physical extent and allow for more complex, physiologically relevant, geometries to be simulated.
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Affiliation(s)
- Greg Russell
- Department of Physics, University of Arizona, Tucson, AZ, USA
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272
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Liver metastases from colorectal cancer treated with conventional and antiangiogenetic chemotherapy: evaluation with liver computed tomography perfusion and magnetic resonance diffusion-weighted imaging. J Comput Assist Tomogr 2012; 35:690-6. [PMID: 22082538 DOI: 10.1097/rct.0b013e318230d905] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE The objectives of the study were to determine whether perfusion computed tomography (CT-p) and magnetic resonance diffusion-weighted imaging (MR-DWI) can allow evaluation of the effects of chemotherapy combined with antiangiogenetic treatment on liver metastases in patients with advanced colorectal cancer and to determine if changes in CT-p and MR-DWI correlate with the response to therapy as assessed by conventional Response Evaluation Criteria in Solid Tumors (RECIST). METHODS Eighteen patients with liver metastases from colorectal cancer underwent CT-p and MR-DWI before and 6 months after chemotherapy and antiangiogenetic treatment. Lesions were classified according to RECIST criteria (complete response [CR], partial response [PR], stable disease [SD], and progressive disease) and calculations of CT-p parameters including blood flow (BF), blood volume (BV), capillary permeability (CP), and MR-DWI apparent diffusion coefficient (ADC) values were performed; RECIST, CT-p, and MR-DWI measurements at baseline and follow-up were tested for statistically significant differences using the paired-samples t test. Baseline and follow-up perfusion parameters of the lesions were also compared on the basis of therapy response assessed by RECIST criteria using independent-samples t test. P < 0.05 was considered indicative of a statistically significant difference for all statistical test. RESULTS Six patients (6/18; 33.3%) were classified as PR (), and the remaining 12 (12/18; 66.7%) were classified as SD. On a per-lesion basis, 2 (2/32; 6.3%) cannot be identified at follow-up, 6 (6/32; 18.8%) showed a decrease in size of more than 30%, and 24 (24/32; 75%) were substantially stable in size. No cases of progressive disease were demonstrated at follow-up. No statistically significant differences were demonstrated between PR, CR, and SD lesions for BF (P = 0.19), BV (P = 0.14), and ADC (P = 0.68) measurements, whereas CP was significantly higher in CR and PR lesions (P = 0.038). Considering differences between baseline and follow-up values, no statistically significant differences were noted between PR and CR lesions versus SD lesions for CT-p values (BF: P = 0.77; BV: P = 0.15; CP: P = 0.64). A statistically significant difference between PR and CR lesions and SD lesions was noted for ADC values (P = 0.047). CONCLUSION Both CT-p and MR-DWI can detect therapy-induced modifications in lesion vascularization before significant changes in size are evident.
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273
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Heijmen L, Verstappen MCHM, Ter Voert EEGW, Punt CJA, Oyen WJG, de Geus-Oei LF, Hermans JJ, Heerschap A, van Laarhoven HWM. Tumour response prediction by diffusion-weighted MR imaging: ready for clinical use? Crit Rev Oncol Hematol 2012; 83:194-207. [PMID: 22269446 DOI: 10.1016/j.critrevonc.2011.12.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 12/06/2011] [Accepted: 12/28/2011] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The efficacy of anticancer therapy is usually evaluated by anatomical imaging. However, this method may be suboptimal for the evaluation of novel treatment modalities, such as targeted therapy. Theoretically, functional assessment of tumour response by diffusion weighted imaging (DWI) is an attractive tool for this purpose and may allow an early prediction of response. The optimal use of this method has still to be determined. METHOD We reviewed the published literature on clinical DWI in the prediction of response to anticancer therapy, especially targeted therapy. Studies investigating the role of DWI in patients with cancer either for response prediction and/or response monitoring were selected for this analysis. RESULTS We identified 24 studies that met our criteria. Most studies showed a significant correlation between (changes in) apparent diffusion coefficient (ADC) values and treatment response. However, in different tumours and studies, both high and low pretreatment ADC were found to be associated with response rate. In the course of treatment, an increase in ADC was associated with response in most cases. CONCLUSION The potential of DWI for (early) response monitoring of anticancer therapies has been demonstrated. However, validation is hampered by the lack of reproducibility and standardisation. We recommend that these issues should be properly addressed prior to further testing the clinical use of DWI in the assessment of treatments.
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Affiliation(s)
- Linda Heijmen
- Department of Medical Oncology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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274
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Ellingson BM, Cloughesy TF, Zaw T, Lai A, Nghiemphu PL, Harris R, Lalezari S, Wagle N, Naeini KM, Carrillo J, Liau LM, Pope WB. Functional diffusion maps (fDMs) evaluated before and after radiochemotherapy predict progression-free and overall survival in newly diagnosed glioblastoma. Neuro Oncol 2012; 14:333-43. [PMID: 22270220 DOI: 10.1093/neuonc/nor220] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Functional diffusion mapping (fDM) has shown promise as a sensitive imaging biomarker for predicting survival in initial studies consisting of a small number of patients, mixed tumor grades, and before routine use of anti-angiogenic therapy. The current study tested whether fDM performed before and after radiochemotherapy could predict progression-free and overall survival in 143 patients with newly diagnosed glioblastoma from 2007 through 2010, many treated with anti-angiogenic therapy after recurrence. Diffusion and conventional MRI scans were obtained before and 4 weeks after completion of radiotherapy and concurrent temozolomide treatment. FDM was created by coregistering pre- and posttreatment apparent diffusion coefficient (ADC) maps and then performing voxel-wise subtraction. FDMs were categorized according to the degree of change in ADC in pre- and posttreatment fluid-attenuated inversion recovery (FLAIR) and contrast-enhancing regions. The volume fraction of fDM-classified increasing ADC(+), decreasing ADC(-), and change in ADC(+/-) were tested to determine whether they were predictive of survival. Both Bonferroni-corrected univariate log-rank analysis and Cox proportional hazards modeling demonstrated that patients with decreasing ADC in a large volume fraction of pretreatment FLAIR or contrast-enhancing regions were statistically more likely to progress earlier and expire sooner than in patients with a lower volume fraction. The current study supports the hypothesis that fDM is a sensitive imaging biomarker for predicting survival in glioblastoma.
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Affiliation(s)
- Benjamin M Ellingson
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 924 Westwood Blvd, Suite 615, Los Angeles, CA 90024, USA.
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275
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Quantifying heterogeneity in human tumours using MRI and PET. Eur J Cancer 2012; 48:447-55. [PMID: 22265426 DOI: 10.1016/j.ejca.2011.12.025] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 12/20/2011] [Indexed: 01/11/2023]
Abstract
Most tumours, even those of the same histological type and grade, demonstrate considerable biological heterogeneity. Variations in genomic subtype, growth factor expression and local microenvironmental factors can result in regional variations within individual tumours. For example, localised variations in tumour cell proliferation, cell death, metabolic activity and vascular structure will be accompanied by variations in oxygenation status, pH and drug delivery that may directly affect therapeutic response. Documenting and quantifying regional heterogeneity within the tumour requires histological or imaging techniques. There is increasing evidence that quantitative imaging biomarkers can be used in vivo to provide important, reproducible and repeatable estimates of tumoural heterogeneity. In this article we review the imaging methods available to provide appropriate biomarkers of tumour structure and function. We also discuss the significant technical issues involved in the quantitative estimation of heterogeneity and the range of descriptive metrics that can be derived. Finally, we have reviewed the existing clinical evidence that heterogeneity metrics provide additional useful information in drug discovery and development and in clinical practice.
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276
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Sinkus R, Van Beers BE, Vilgrain V, DeSouza N, Waterton JC. Apparent diffusion coefficient from magnetic resonance imaging as a biomarker in oncology drug development. Eur J Cancer 2012; 48:425-31. [PMID: 22226479 DOI: 10.1016/j.ejca.2011.11.034] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 11/27/2011] [Indexed: 12/13/2022]
Abstract
Magnetic resonance imaging (MRI) can be made sensitive to diffusion of water molecules in biological tissues: this phenomenon can be quantitated to provide a biomarker, the apparent diffusion coefficient (ADC). Over the past decade, evidence has accumulated from numerous clinical and animal studies that ADC is abnormal in tumours; that elevated ADC reflects an elevated non-cellular fraction; and that acute increases in ADC following therapy can indicate that tumour cells have been killed. However there remain substantial challenges in ensuring robust and valid ADC measurements, particularly in multicentre studies in common sites of metastasis such as lung and liver. Moreover, there is uncertainty about how best to select the timing of observation post-therapy to avoid false-negatives, and how to minimise the confounding factors which could decouple drug-induced ADC increase from drug-induced cell kill. In this review we summarise the physical basis of the biomarker, the evidence that it reflects non-viable fraction, particularly in extracranial tumours, and suggest a roadmap for validation and qualification.
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Affiliation(s)
- Ralph Sinkus
- Centre de Recherche Biomédicale Bichat Beaujon, Beaujon Hospital, Clichy, France.
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277
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Diffusion-Weighted MRI Versus 18F-FDG PET/CT: Performance as Predictors of Tumor Treatment Response and Patient Survival in Patients With Non–Small Cell Lung Cancer Receiving Chemoradiotherapy. AJR Am J Roentgenol 2012; 198:75-82. [DOI: 10.2214/ajr.11.6525] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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278
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Wu J, Johnson TD, Galbán CJ, Chenevert TL, Meyer CR, Rehemtulla A, Hamstra DA, Ross BD. Predicting treatment efficacy via quantitative magnetic resonance imaging: a Bayesian joint model. J R Stat Soc Ser C Appl Stat 2012; 61:83-98. [PMID: 22577240 PMCID: PMC3346284 DOI: 10.1111/j.1467-9876.2011.01015.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The prognosis for patients with high grade gliomas is poor, with a median survival of 1 year. Treatment efficacy assessment is typically unavailable until 5-6 months post diagnosis. Investigators hypothesize that quantitative magnetic resonance imaging can assess treatment efficacy 3 weeks after therapy starts, thereby allowing salvage treatments to begin earlier. The purpose of this work is to build a predictive model of treatment efficacy by using quantitative magnetic resonance imaging data and to assess its performance. The outcome is 1-year survival status. We propose a joint, two-stage Bayesian model. In stage I, we smooth the image data with a multivariate spatiotemporal pairwise difference prior. We propose four summary statistics that are functionals of posterior parameters from the first-stage model. In stage II, these statistics enter a generalized non-linear model as predictors of survival status. We use the probit link and a multivariate adaptive regression spline basis. Gibbs sampling and reversible jump Markov chain Monte Carlo methods are applied iteratively between the two stages to estimate the posterior distribution. Through both simulation studies and model performance comparisons we find that we can achieve higher overall correct classification rates by accounting for the spatiotemporal correlation in the images and by allowing for a more complex and flexible decision boundary provided by the generalized non-linear model.
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Affiliation(s)
- Jincao Wu
- University of Michigan, Ann Arbor, USA
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279
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Affiliation(s)
- Ian F Parney
- Department of Neurological Surgery, Mayo Clinic, Rochester, MN, USA.
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280
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Qian Y, Zhao T, Zheng H, Weimer J, Boada FE. High-resolution sodium imaging of human brain at 7 T. Magn Reson Med 2011; 68:227-33. [PMID: 22144258 DOI: 10.1002/mrm.23225] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 08/29/2011] [Accepted: 08/30/2011] [Indexed: 01/17/2023]
Abstract
The feasibility of high-resolution sodium magnetic resonance imaging on human brain at 7 T was demonstrated in this study. A three-dimensional anisotropic resolution data acquisition was used to address the challenge of low signal-to-noise ratio associated with high resolution. Ultrashort echo-time sequence was used for the anisotropic data acquisition. Phantoms and healthy human brains were studied on a whole-body 7-T magnetic resonance imaging scanner. Sodium images were obtained at two high nominal in-plane resolutions (1.72 and 0.86 mm) at a slice thickness of 4 mm. Signal-to-noise ratio in the brain image (cerebrospinal fluid) was measured as 14.4 and 6.8 at the two high resolutions, respectively. The actual in-plane resolution was measured as 2.9 and 1.6 mm, 69-86% larger than their nominal values. The quantification of sodium concentration on the phantom and brain images enabled better accuracy at the high nominal resolutions than at the low nominal resolution of 3.44 mm (measured resolution 5.5 mm) due to the improvement of in-plane resolution.
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Affiliation(s)
- Yongxian Qian
- MR Research Center, Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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281
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Wu X, Kellokumpu-Lehtinen PL, Pertovaara H, Korkola P, Soimakallio S, Eskola H, Dastidar P. Diffusion-weighted MRI in early chemotherapy response evaluation of patients with diffuse large B-cell lymphoma--a pilot study: comparison with 2-deoxy-2-fluoro- D-glucose-positron emission tomography/computed tomography. NMR IN BIOMEDICINE 2011; 24:1181-90. [PMID: 21387451 DOI: 10.1002/nbm.1689] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 12/03/2010] [Accepted: 01/11/2011] [Indexed: 05/22/2023]
Abstract
To determine the feasibility of diffusion-weighted MRI (DWI) in the evaluation of the early chemotherapeutic response in patients with aggressive non-Hodgkin's lymphoma (NHL), eight patients with histologically proven diffuse large B-cell lymphoma were imaged by MRI, including DWI, and positron emission tomography/computed tomography (PET/CT) before treatment (E1), and after 1 week (E2) and two cycles (E3) of chemotherapy. In all patients, whole-body screening using T(1) - and T(2) -weighted images in the coronal plane was performed. To quantitatively evaluate the chemotherapeutic response, axial images including DWI were acquired. Apparent diffusion coefficient (ADC) maps were reconstructed, and the ADC value of the tumor was measured. In addition, the tumor volume was estimated on axial T(2) -weighted images. The maximum standardized uptake value (SUV(max) ) and active tumor volume were measured on fused PET/CT images. Lymphomas showed high signal intensity on DW images and low signal intensity on ADC maps, except for necrotic foci. The mean pre-therapy ADC was 0.71 × 10(-3) mm(2) /s; it increased by 77% at E2 (p < 0.05) and 24% more at E3 (insignificant); the total increase was 106% (p < 0.05). The mean tumor volume by MRI was 276 mL at baseline; it decreased by 58% at E2 (p < 0.05) and 65% more at E3 (p < 0.05), giving a total decrease of 84% (p < 0.05). All the imaged pre-therapy tumors were strongly positive on PET/CT, with a mean SUV(max) of 20. The SUV(max) decreased by 60% at E2 (p < 0.05) and 59% more at E3 (p < 0.05), giving a total decrease of 83% (p < 0.05). The active tumor burden decreased by 66% at E2 (p < 0.05). At baseline, both central and peripheral tumor ADC values correlated inversely with SUV(max) (p < 0.05), and also correlated inversely with active tumor burden on PET/CT and with tumor volume on MRI at E2 (p < 0.05). In conclusion, the results of DWI in combination with whole-body MRI were comparable with those of integrated PET/CT.
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Affiliation(s)
- Xingchen Wu
- Department of Oncology, Tampere University Hospital, Teiskontie 35, Tampere, Finland.
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282
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Advantages of high b-value diffusion-weighted imaging to diagnose pseudo-responses in patients with recurrent glioma after bevacizumab treatment. Eur J Radiol 2011; 81:2805-10. [PMID: 22100373 DOI: 10.1016/j.ejrad.2011.10.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 10/15/2011] [Accepted: 10/19/2011] [Indexed: 01/18/2023]
Abstract
BACKGROUND The diagnosis of pseudo-responses after bevacizumab treatment is difficult. Because diffusion-weighted imaging (DWI) is associated with cell density, it may facilitate the differentiation between true- and pseudo-responses. Furthermore, as high b-value DWI is even more sensitive to diffusion, it has been reported to be diagnostically useful in various clinical settings. MATERIALS AND METHODS Between September 2008 and May 2011, 10 patients (5 males, 5 females; age range 6-65 years) with recurrent glioma were treated with bevacizumab. All underwent pre- and post-treatment MRI including T2- or FLAIR imaging, post-gadolinium contrast T1-weighted imaging, and DWI with b-1000 and b-4000. Response rates were evaluated by MacDonald- and by response assessment in neuro-oncology working group (RANO) criteria. We also assessed the response rate by calculating the size of high intensity areas using high b-value diffusion-weighted criteria. Prognostic factors were evaluated using Kaplan-Meier survival curves (log-rank test). RESULTS It was easier to identify pseudo-responses with RANO- than MacDonald criteria, however the reduction of edema by bevacizumab rendered the early diagnosis of tumor progression difficult by RANO criteria. In some patients with recurrent glioma treated with bevacizumab, high b-value diffusion-weighted criteria did, while MacDonald- and RANO criteria did not identify pseudo-responses at an early point after the start of therapy. DISCUSSION AND CONCLUSION High b-value DWI reflects cell density more accurately than regular b-value DWI. Our findings suggest that in patients with recurrent glioma, high b-value diffusion-weighted criteria are useful for the differentiation between pseudo- and true responses to treatment with bevacizumab.
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283
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Budde MD, Gold E, Jordan EK, Frank JA. Differential microstructure and physiology of brain and bone metastases in a rat breast cancer model by diffusion and dynamic contrast enhanced MRI. Clin Exp Metastasis 2011; 29:51-62. [PMID: 22042553 DOI: 10.1007/s10585-011-9428-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 09/29/2011] [Indexed: 12/17/2022]
Abstract
Pharmacological approaches to treat breast cancer metastases in the brain have been met with limited success. In part, the impermeability of the blood brain barrier (BBB) has hindered delivery of chemotherapeutic agents to metastatic tumors in the brain. BBB-permeable chemotherapeutic drugs are being developed, and noninvasively assessing the efficacy of these agents will be important in both preclinical and clinical settings. In this regard, dynamic contrast enhanced (DCE) and diffusion weighted imaging (DWI) are magnetic resonance imaging (MRI) techniques to monitor tumor vascular permeability and cellularity, respectively. In a rat model of metastatic breast cancer, we demonstrate that brain and bone metastases develop with distinct physiological characteristics as measured with MRI. Specifically, brain metastases have limited permeability of the BBB as assessed with DCE and an increased apparent diffusion coefficient (ADC) measured with DWI compared to the surrounding brain. Microscopically, brain metastases were highly infiltrative, grew through vessel co-option, and caused extensive edema and injury to the surrounding neurons and their dendrites. By comparison, metastases situated in the leptomenengies or in the bone had high vascular permeability and significantly lower ADC values suggestive of hypercellularity. On histological examination, tumors in the bone and leptomenengies were solid masses with distinct tumor margins. The different characteristics of these tissue sites highlight the influence of the microenvironment on metastatic tumor growth. In light of these results, the suitability of DWI and DCE to evaluate the response of chemotherapeutic and anti-angiogenic agents used to treat co-opted brain metastases, respectively, remains a formidable challenge.
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Affiliation(s)
- Matthew D Budde
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Building 10, B1N256, Bethesda, MD 20892, USA.
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284
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Hatakenaka M, Shioyama Y, Nakamura K, Yabuuchi H, Matsuo Y, Sunami S, Kamitani T, Yoshiura T, Nakashima T, Nishikawa K, Honda H. Apparent diffusion coefficient calculated with relatively high b-values correlates with local failure of head and neck squamous cell carcinoma treated with radiotherapy. AJNR Am J Neuroradiol 2011; 32:1904-10. [PMID: 21778248 DOI: 10.3174/ajnr.a2610] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND AND PURPOSE Few studies have investigated the relationship between ADC and clinical outcome in HNSCC. Our hypothesis has that relatively high pretreatment ADC would correlate with local failure of HNSCC treated with radiation therapy. MATERIALS AND METHODS This includes prospective and validation studies. Seventeen patients treated with radiation therapy for primary HNSCC completed the prospective study. Variables considered to affect local failure including MR imaging-related parameters such as ADC and its change ratio were compared between patients with local failure and controls, and those showing difference or association with local failure were further tested by survival analysis. Furthermore, variables were analyzed in 40 patients enrolled in the validation study. RESULTS Relatively high ADC calculated with b-values (300, 500, 750, and 1000 s/mm(2)) before treatment, high ADC increase ratio, and treatment method (chemoradiotherapy versus radiation therapy alone) revealed significant difference between patients with local failure and controls or association with local failure. In Cox proportional hazard testing, high ADC before treatment alone showed significant association with local failure (P = .0186). In the validation study, tumor volume before treatment, high ADC before treatment, T stage (T12 versus T34), and treatment method showed significance. Tumor volume before treatment (P = .0217) and high ADC before treatment (P = .0001) revealed significant association with local failure in Cox proportional hazard testing. High ADC before treatment was superior to tumor volume before treatment regarding association with local failure. CONCLUSIONS These results suggest pretreatment ADC obtained at high b-values as well as tumor volume correlate with local failure of HNSCC treated with radiation therapy.
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Affiliation(s)
- M Hatakenaka
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Japan.
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285
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Peeters F, Rommel D, Abarca-Quinones J, Grégoire V, Duprez T. Early (72-hour) detection of radiotherapy-induced changes in an experimental tumor model using diffusion-weighted imaging, diffusion tensor imaging, and Q-space imaging parameters: a comparative study. J Magn Reson Imaging 2011; 35:409-17. [PMID: 21990132 DOI: 10.1002/jmri.22836] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Accepted: 09/09/2011] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To assess and compare the potential of various diffusion-related magnetic resonance imaging (MRI) parameters to detect early radiotherapy (RT)-induced changes in tumors. MATERIALS AND METHODS Nineteen tumors in a rat model were imaged on a clinical 3T system before and 72 hours after a single RT session. Diffusion imaging was performed using an echo planar sequence containing 16 b-factors and six gradient directions. This allowed us to perform a tensor analysis of mono- and biexponential decays and a q-space analysis. Parametric maps (both trace and fractional anisotropy) were reconstructed for: 2-point apparent diffusion coefficient (ADC), 16-point ADC, biexponential amplitudes and ADCs, and height, width, and kurtosis of the probability density function (PDF). A texture analysis yielded quantities such as average and contrast. The sensitivity of diffusion-related parameters was quantified in terms of the mean relative difference (when comparing pre- and post-RT status). RESULTS Traces and anisotropies display differences in response to RT. Average traces are most sensitive for ADCs and kurtosis. Average anisotropies are all very sensitive except the slow biexponential component. The best contrast (traces) was found for the ADCs and the width of the PDF. CONCLUSION ADC performed well, but high b-values analysis added extra sensitive parameters for monitoring early RT-induced changes.
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Affiliation(s)
- Frank Peeters
- Department of Radiology and Medical Imaging, Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
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286
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Jung SH, Heo SH, Kim JW, Jeong YY, Shin SS, Soung MG, Kim HR, Kang HK. Predicting response to neoadjuvant chemoradiation therapy in locally advanced rectal cancer: diffusion-weighted 3 Tesla MR imaging. J Magn Reson Imaging 2011; 35:110-6. [PMID: 21989997 DOI: 10.1002/jmri.22749] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 07/19/2011] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To evaluate the efficacy of diffusion-weighted imaging (DWI) on 3 Tesla (T) MR imaging to predict the tumor response to neoadjuvant chemoradiation therapy (CRT) in patients with locally advanced rectal cancer. MATERIALS AND METHODS Thirty-five patients who underwent neoadjuvant CRT and subsequent surgical resection were included. Tumor volume was measured on T2-weighted MR images before and after neoadjuvant CRT and the percentage of tumor volume reduction was calculated. The apparent diffusion coefficient (ADC) value was measured on the DWI before and after neoadjuvant CRT, and the change of ADC (Δ ADC) was calculated. The histopathologic response was categorized either as a responder to CRT or as a nonresponder. The relationship between the ADC parameters and the percentage of tumor volume reduction or histopathologic response was then evaluated. RESULTS There was a significant correlation between tumor volume reduction and pre-CRT ADC and Δ ADC, respectively (r = -0.352, r = 0.615). Pre-CRT ADC of the histopathologic responders was significantly lower than that of the histopathologic nonresponders (P = 0.034). Δ ADC of the histopathologic responders was significantly higher than that of the histopathologic nonresponders (P < 0.005). CONCLUSION DWI on 3T MR imaging may be a promising technique for helping to predict and monitor the treatment response to neoadjuvant CRT in patients with locally advanced rectal cancer.
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Affiliation(s)
- Se Hee Jung
- Department of Radiology, Chonnam National University Hospital, Dong-gu, Gwangju, South Korea
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287
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Wang Y, Miller FH, Chen ZE, Merrick L, Mortele KJ, Hoff FL, Hammond NA, Yaghmai V, Vahid Y, Nikolaidis P. Diffusion-weighted MR imaging of solid and cystic lesions of the pancreas. Radiographics 2011; 31:E47-64. [PMID: 21721197 DOI: 10.1148/rg.313105174] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Diffusion-weighted magnetic resonance (MR) imaging is increasingly used in the detection and characterization of pancreatic lesions. Diffusion-weighted imaging may provide additional information to radiologists evaluating patients who have cystic or solid neoplasms of the pancreas. Because of greater freedom of motion of water molecules in fluid-rich environments, simple cysts in the pancreas have higher signal intensity on diffusion-weighted images with a b value of 0 sec/mm2 and lower signal intensity on high-b-value images. High apparent diffusion coefficient (ADC) values can be obtained on ADC maps because of the T2 “shine-through” effect. In contrast, solid neoplasms of the pancreas show increased signal intensity relative to the pancreas on diffusion-weighted images with a b value of 0 sec/mm2 and relatively high signal intensity on high-b-value images. Diffusion-weighted imaging can help detect solid pancreatic neoplasms with extremely dense cellularity or extracellular fibrosis by demonstrating significantly low ADC values, and these neoplasms may be better detected on diffusion-weighted MR images because of better contrast, although the resolution is generally worse. However, diffusion-weighted imaging may not be capable of helping definitively characterize solid lesions as inflammatory or neoplastic because of an overlap in ADC values between the two types. For example, it is difficult to distinguish poorly differentiated pancreatic adenocarcinoma from mass-forming pancreatitis at diffusion-weighted imaging because of similarly low ADC values attributed to dense fibrosis.
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Affiliation(s)
- Yi Wang
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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288
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Ollivro S, Eliat PA, Hitti E, Tran L, de Certaines JD, Saint-Jalmes H. Preliminary MRI Quality Assessment and Device Acceptance Guidelines for a Multicenter Bioclinical Study: The GO Glioblastoma Project. J Neuroimaging 2011; 22:336-42. [DOI: 10.1111/j.1552-6569.2011.00638.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Ellingson BM, Cloughesy TF, Lai A, Mischel PS, Nghiemphu PL, Lalezari S, Schmainda KM, Pope WB. Graded functional diffusion map-defined characteristics of apparent diffusion coefficients predict overall survival in recurrent glioblastoma treated with bevacizumab. Neuro Oncol 2011; 13:1151-61. [PMID: 21856685 DOI: 10.1093/neuonc/nor079] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Diffusion imaging has shown promise as a predictive and prognostic biomarker in glioma. We assessed the ability of graded functional diffusion maps (fDMs) and apparent diffusion coefficient (ADC) characteristics to predict overall survival (OS) in recurrent glioblastoma multiforme (GBM) patients treated with bevacizumab. Seventy-seven patients with recurrent GBMs were retrospectively examined. MRI scans were obtained before and approximately 6 weeks after treatment with bevacizumab. Graded fDMs were created by registering datasets to each patient's pretreatment scan and then performing voxel-wise subtraction between post- and pretreatment ADC maps. Voxels were categorized according to the degree of change in ADC within pretreatment fluid-attenuated inversion recovery (FLAIR) and contrast-enhancing regions of interest (ROIs). We found that the volume of tissue showing decreased ADC within both FLAIR and contrast-enhancing regions stratified OS (log-rank, P < .05). fDMs applied to contrast-enhancing ROIs more accurately predicted OS compared with fDMs applied to FLAIR ROIs. Graded fDMs (showing voxels with decreased ADC between 0.25 and 0.4 µm(2)/ms) were more predictive of OS than traditional (single threshold) fDMs, and the predictive ability of graded fDMs could be enhanced even further by adding the ADC characteristics from the fDM-classified voxels to the analysis (log-rank, P < .001). These results demonstrate that spatially resolved diffusion-based tumor metrics are a powerful imaging biomarker of survival in patients with recurrent GBM treated with bevacizumab.
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Affiliation(s)
- Benjamin M Ellingson
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 924 Westwood Blvd., Suite 650, Los Angeles, CA 90024, USA.
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290
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Heiss WD, Raab P, Lanfermann H. Multimodality assessment of brain tumors and tumor recurrence. J Nucl Med 2011; 52:1585-600. [PMID: 21840931 DOI: 10.2967/jnumed.110.084210] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Neuroimaging plays a significant role in the diagnosis of intracranial tumors, especially brain gliomas, and must consist of an assessment of location and extent of the tumor and of its biologic activity. Therefore, morphologic imaging modalities and functional, metabolic, or molecular imaging modalities should be combined for primary diagnosis and for following the course and evaluating therapeutic effects. MRI is the gold standard for providing detailed morphologic information and can supply some additional insights into metabolism (MR spectroscopy) and perfusion (perfusion-weighted imaging) but still has limitations in identifying tumor grade, invasive growth into neighboring tissue, and treatment-induced changes, as well as recurrences. These insights can be obtained by various PET modalities, including imaging of glucose metabolism, amino acid uptake, nucleoside uptake, and hypoxia. Diagnostic accuracy can benefit from coregistration of PET results and MRI, combining the high-resolution morphologic images with the biologic information. These procedures are optimized by the newly developed combination of PET and MRI modalities, permitting the simultaneous assessment of morphologic, functional, metabolic, and molecular information on the human brain.
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291
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Applications of molecular imaging. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 95:237-98. [PMID: 21075334 DOI: 10.1016/b978-0-12-385071-3.00009-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Today molecular imaging technologies play a central role in clinical oncology. The use of imaging techniques in early cancer detection, treatment response, and new therapy development is steadily growing and has already significantly impacted on clinical management of cancer. In this chapter, we overview three different molecular imaging technologies used for the understanding of disease biomarkers, drug development, or monitoring therapeutic outcome. They are (1) optical imaging (bioluminescence and fluorescence imaging), (2) magnetic resonance imaging (MRI), and (3) nuclear imaging (e.g., single-photon emission computed tomography (SPECT) and positron emission tomography (PET)). We review the use of molecular reporters of biological processes (e.g., apoptosis and protein kinase activity) for high-throughput drug screening and new cancer therapies, diffusion MRI as a biomarker for early treatment response and PET and SPECT radioligands in oncology.
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A feasibility study of parametric response map analysis of diffusion-weighted magnetic resonance imaging scans of head and neck cancer patients for providing early detection of therapeutic efficacy. Transl Oncol 2011; 2:184-90. [PMID: 19701503 DOI: 10.1593/tlo.09175] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 07/02/2009] [Accepted: 07/06/2009] [Indexed: 01/05/2023] Open
Abstract
The parametric response map (PRM) was evaluated as an early surrogate biomarker for monitoring treatment-induced tissue alterations in patients with head and neck squamous cell carcinoma (HNSCC). Diffusion-weighted magnetic resonance imaging (DW-MRI) was performed on 15 patients with HNSCC at baseline and 3 weeks after treatment initiation of a nonsurgical organ preservation therapy (NSOPT) using concurrent radiation and chemotherapy. PRM was applied on serial apparent diffusion coefficient (ADC) maps that were spatially aligned using a deformable image registration algorithm to measure the tumor volume exhibiting significant changes in ADC (PRM(ADC)). Pretherapy and midtherapy ADC maps, quantified from the DWIs, were analyzed by monitoring the percent change in whole-tumor mean ADC and the PRM metric. The prognostic values of percentage change in tumor volume and mean ADC and PRM(ADC) as a treatment response biomarker were assessed by correlating with tumor control at 6 months. Pixel-wise differences as part of PRM(ADC) analysis revealed regions where water mobility increased. Analysis of the tumor ADC histograms also showed increases in mean ADC as early as 3 weeks into therapy in patients with a favorable outcome. Nevertheless, the percentage change in mean ADC was found to not correlate with tumor control at 6 months. In contrast, significant differences in PRM(ADC) and percentage change in tumor volume were observed between patients with pathologically different outcomes. Observations from this study have found that diffusion MRI, when assessed by PRM(ADC), has the potential to provide both prognostic and spatial information during NSOPT of head and neck cancer.
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293
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Kim YC, Lim JS, Keum KC, Kim KA, Myoung S, Shin SJ, Kim MJ, Kim NK, Suh J, Kim KW. Comparison of diffusion-weighted MRI and MR volumetry in the evaluation of early treatment outcomes after preoperative chemoradiotherapy for locally advanced rectal cancer. J Magn Reson Imaging 2011; 34:570-6. [PMID: 21751285 DOI: 10.1002/jmri.22696] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 05/24/2011] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To compare diffusion-weighted imaging (DWI) and magnetic resonance (MR) volumetry for predicting treatment outcomes of locally advanced rectal cancers with preoperative chemoradiotherapy (CRT). MATERIALS AND METHODS This prospective study was approved by our Institutional Review Board. Thirty-four patients underwent three MR examinations: pre-CRT (before CRT), early CRT (2 weeks after CRT initiation), and post-CRT (before surgery). The tumor apparent diffusion coefficient (ADC), ADC increase rate, and volume reduction rate were compared between responders and nonresponders using three reference standards: downstaging, modified Response Evaluation Criteria in Solid Tumors (mRECIST), and tumor regression grade (TRG). For DWI and volumetry, differences between responders and nonresponders were assessed by receiver operating characteristic analysis. RESULTS The median early tumor volume reduction rate of responders, subgrouped by downstaging and mRECIST (47.97% and 53.97%, respectively), was significantly higher than that of nonresponders (20.94% and 20.36%; P = 0.0024 and 0.0001, respectively), but there were no significant differences in pre-CRT ADC and early ADC increase rate using all references. When using the downstaging and mRECIST, the diagnostic performance of early tumor volume reduction rate (Az = 0.81 and 0.94, respectively) was higher than that of pre-CRT ADC (Az = 0.55 and 0.62; P = 0.033 and 0.007) and early ADC increase rate (Az = 0.58 and 0.64; P = 0.055 and 0.01) for predicting the treatment outcome. For TRG, there were no significant differences between DWI and volumetry. CONCLUSION Early tumor volume reduction rate at the second week after CRT initiation may be a better indicator than DWI based on the mean ADC measurements for predicting CRT treatment outcome.
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Affiliation(s)
- Young Chul Kim
- Department of Radiology, Research Institute of Radiological Science, Yonsei University Health System, Seoul, Republic of Korea
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294
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Lee CH, Braga L, de Campos ROP, Semelka RC. Hepatic tumor response evaluation by MRI. NMR IN BIOMEDICINE 2011; 24:721-733. [PMID: 21793076 DOI: 10.1002/nbm.1637] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 09/29/2010] [Accepted: 10/07/2010] [Indexed: 05/31/2023]
Abstract
Noninvasive evaluation of hepatic tumor response is necessary to improve the survival rate and quality of life of cancer patients. Among radiologic imaging modalities, MRI plays a significant role in the management of patients with hepatic tumor and is crucial for diagnosis, treatment planning and assessment of response or recurrence, because of its high contrast resolution, lack of ionizing radiation and the possibility of performing functional imaging sequences. This review provides an overview of the MRI findings after various treatments in patients with primary and secondary focal liver malignancies. The imaging methods described focus on the recent trends of using MRI techniques as biomarkers for disease. We also describe the appearance of successful and incomplete response for the various forms of treatment, including transcatheter arterial chemoembolization, ablative therapy, systemic chemotherapy and radiation therapy. Dynamic contrast-enhanced MRI is regarded as an established noninvasive method and potential biomarker for tumor detection, as well as for the characterization of the tumor response. Diffusion-weighted MRI, perfusion-weighted MRI and MRS are also promising functional biomarkers to help select patients for various therapies and to assess the response to treatments. However, further validation and standardization should be performed before their widespread use as imaging biomarkers.
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Affiliation(s)
- Chang Hee Lee
- Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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295
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Nelson SJ. Assessment of therapeutic response and treatment planning for brain tumors using metabolic and physiological MRI. NMR IN BIOMEDICINE 2011; 24:734-49. [PMID: 21538632 PMCID: PMC3772179 DOI: 10.1002/nbm.1669] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 11/14/2010] [Accepted: 12/10/2010] [Indexed: 05/26/2023]
Abstract
MRI is routinely used for diagnosis, treatment planning and assessment of response to therapy for patients with glioma. Gliomas are spatially heterogeneous and infiltrative lesions that are quite variable in terms of their response to therapy. Patients classified as having low-grade histology have a median overall survival of 7 years or more, but need to be monitored carefully to make sure that their tumor does not upgrade to a more malignant phenotype. Patients with the most aggressive grade IV histology have a median overall survival of 12-15 months and often undergo multiple surgeries and adjuvant therapies in an attempt to control their disease. Despite improvements in the spatial resolution and sensitivity of anatomic images, there remain considerable ambiguities in the interpretation of changes in the size of the gadolinium-enhancing lesion on T(1) -weighted images as a measure of treatment response, and in differentiating between treatment effects and infiltrating tumor within the larger T(2) lesion. The planning of focal therapies, such as surgery, radiation and targeted drug delivery, as well as a more reliable assessment of the response to therapy, would benefit considerably from the integration of metabolic and physiological imaging techniques into routine clinical MR examinations. Advanced methods that have been shown to provide valuable data for patients with glioma are diffusion, perfusion and spectroscopic imaging. Multiparametric examinations that include the acquisition of such data are able to assess tumor cellularity, hypoxia, disruption of normal tissue architecture, changes in vascular density and vessel permeability, in addition to the standard measures of changes in the volume of enhancing and nonenhancing anatomic lesions. This is particularly critical for the interpretation of the results of Phase I and Phase II clinical trials of novel therapies, which are increasingly including agents that are designed to have anti-angiogenic and anti-proliferative properties as opposed to having a direct effect on tumor cell viability.
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Affiliation(s)
- Sarah J Nelson
- University of California at San Francisco - Mission Bay, San Francisco, CA, USA.
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296
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Ellingson BM, Cloughesy TF, Lai A, Nghiemphu PL, Lalezari S, Zaw T, Motevalibashinaeini K, Mischel PS, Pope WB. Quantification of edema reduction using differential quantitative T2 (DQT2) relaxometry mapping in recurrent glioblastoma treated with bevacizumab. J Neurooncol 2011; 106:111-9. [PMID: 21706273 DOI: 10.1007/s11060-011-0638-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 06/17/2011] [Indexed: 01/18/2023]
Abstract
The purpose of the current study was to quantify the reduction in T2 signal abnormality accompanying administration of the anti-angiogenic drug bevacizumab in recurrent glioblastoma (GBM) patients using a voxel-wise differential quantitative T2 (DQT2) mapping technique. Twenty-six patients with recurrent GBM treated with bevacizumab were scanned before and 4-6 weeks after treatment on a 1.5T clinical MR scanner. Quantitative T2 maps were created from proton density and T2-weighted images acquired using a standard multi-echo fast-spin echo sequence. T2 maps after treatment were co-registered with T2 maps prior to treatment in the same patient, and then voxel-wise subtraction was performed to create DQT2 maps for each patient. Results suggest DQT2 maps allow visualization and quantification of voxel-wise T2 changes resulting from anti-VEGF therapy. Results demonstrated a significant decrease in T2 within pre-treatment T2 abnormal regions (mean reduction = 49.4 ms at 1.5T) following anti-VEGF treatment (Wilcoxon signed rank test, P < 0.0001). An elevated residual, post-treatment, median T2 was predictive of both progression-free (Log-rank, P = 0.0074) and overall survival (Log-rank, P = 0.0393).
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Affiliation(s)
- Benjamin M Ellingson
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 924 Westwood Blvd., Suite 650, Los Angeles, CA 90095, USA.
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297
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Ellingson BM, Cloughesy TF, Lai A, Nghiemphu PL, Pope WB. Nonlinear registration of diffusion-weighted images improves clinical sensitivity of functional diffusion maps in recurrent glioblastoma treated with bevacizumab. Magn Reson Med 2011; 67:237-45. [PMID: 21702063 DOI: 10.1002/mrm.23003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 04/21/2011] [Accepted: 04/24/2011] [Indexed: 01/17/2023]
Abstract
Diffusion-weighted imaging estimates of apparent diffusion coefficient (ADC) have shown sensitivity to brain tumor cellularity as well as response to therapy. Functional diffusion maps (fDMs) exploit these principles by examining voxelwise changes in ADC within the same patient over time. Currently, the fDM technique involves linear image registration of ADC maps from subsequent follow-up times to pretreatment ADC maps; however, misregistration of ADC maps due to geometric distortions as well as mass effect from growing tumor can confound fDM measurements. In this study, we compare the use of a nonlinear registration scheme to the current linear fDM technique in 70 patients with recurrent glioblastoma multiforme treated with bevacizumab. Results suggest that nonlinear registration of pretreatment ADC maps to post-treatment ADC maps improves the clinical predictability, sensitivity, and specificity of fDMs for both progression-free and overall survival.
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Affiliation(s)
- Benjamin M Ellingson
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.
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298
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Røe K, Kakar M, Seierstad T, Ree AH, Olsen DR. Early prediction of response to radiotherapy and androgen-deprivation therapy in prostate cancer by repeated functional MRI: a preclinical study. Radiat Oncol 2011; 6:65. [PMID: 21651782 PMCID: PMC3130663 DOI: 10.1186/1748-717x-6-65] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 06/08/2011] [Indexed: 01/04/2023] Open
Abstract
Background In modern cancer medicine, morphological magnetic resonance imaging (MRI) is routinely used in diagnostics, treatment planning and assessment of therapeutic efficacy. During the past decade, functional imaging techniques like diffusion-weighted (DW) MRI and dynamic contrast-enhanced (DCE) MRI have increasingly been included into imaging protocols, allowing extraction of intratumoral information of underlying vascular, molecular and physiological mechanisms, not available in morphological images. Separately, pre-treatment and early changes in functional parameters obtained from DWMRI and DCEMRI have shown potential in predicting therapy response. We hypothesized that the combination of several functional parameters increased the predictive power. Methods We challenged this hypothesis by using an artificial neural network (ANN) approach, exploiting nonlinear relationships between individual variables, which is particularly suitable in treatment response prediction involving complex cancer data. A clinical scenario was elicited by using 32 mice with human prostate carcinoma xenografts receiving combinations of androgen-deprivation therapy and/or radiotherapy. Pre-radiation and on days 1 and 9 following radiation three repeated DWMRI and DCEMRI acquisitions enabled derivation of the apparent diffusion coefficient (ADC) and the vascular biomarker Ktrans, which together with tumor volumes and the established biomarker prostate-specific antigen (PSA), were used as inputs to a back propagation neural network, independently and combined, in order to explore their feasibility of predicting individual treatment response measured as 30 days post-RT tumor volumes. Results ADC, volumes and PSA as inputs to the model revealed a correlation coefficient of 0.54 (p < 0.001) between predicted and measured treatment response, while Ktrans, volumes and PSA gave a correlation coefficient of 0.66 (p < 0.001). The combination of all parameters (ADC, Ktrans, volumes, PSA) successfully predicted treatment response with a correlation coefficient of 0.85 (p < 0.001). Conclusions We have in a preclinical investigation showed that the combination of early changes in several functional MRI parameters provides additional information about therapy response. If such an approach could be clinically validated, it may become a tool to help identifying non-responding patients early in treatment, allowing these patients to be considered for alternative treatment strategies, and, thus, providing a contribution to the development of individualized cancer therapy.
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Affiliation(s)
- Kathrine Røe
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, PO Box 4953 Nydalen, 0424 Oslo, Norway.
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299
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Abstract
Cells undergoing apoptosis show a plethora of time-dependent changes. The available tools for imaging apoptosis in live cells rely either on the detection of the activity of caspases, or on the visualization of exposure of phosphatidyl serine in the outer leaflet of the cell membrane. We report here a novel method for the detection of mitochondrial events during apoptosis, namely translocation of Bax to mitochondria and release of cytochrome c (Cyt c) using bimolecular fluorescence complementation. Expression of split yellow fluorescent protein (YFP) fragments fused to Bax and Cyt c, resulted in robust induction of YFP fluorescence at the mitochondria of apoptotic cells with very low background. In vivo expression of split YFP protein fragments in liver hepatocytes and intra-vital imaging of subcutaneous tumor showed elevated YFP fluorescence upon apoptosis induction. Thus, YFP complementation could be applied for high-throughput screening and in vivo molecular imaging of mitochondrial events during apoptosis.
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300
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Gore JC, Manning HC, Quarles CC, Waddell KW, Yankeelov TE. Magnetic resonance in the era of molecular imaging of cancer. Magn Reson Imaging 2011; 29:587-600. [PMID: 21524870 PMCID: PMC3285504 DOI: 10.1016/j.mri.2011.02.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 02/26/2011] [Indexed: 12/16/2022]
Abstract
Magnetic resonance imaging (MRI) has played an important role in the diagnosis and management of cancer since it was first developed, but other modalities also continue to advance and provide complementary information on the status of tumors. In the future, there will be a major continuing role for noninvasive imaging in order to obtain information on the location and extent of cancer, as well as assessments of tissue characteristics that can monitor and predict treatment response and guide patient management. Developments are currently being undertaken that aim to provide improved imaging methods for the detection and evaluation of tumors, for identifying important characteristics of tumors such as the expression levels of cell surface receptors that may dictate what types of therapy will be effective and for evaluating their response to treatments. Molecular imaging techniques based mainly on radionuclide imaging can depict numerous, specific, cellular and molecular markers of disease and have unique potential to address important clinical and research challenges. In this review, we consider what continuing and evolving roles will be played by MRI in this era of molecular imaging. We discuss some of the challenges for MRI of detecting imaging agents that report on molecular events, but highlight also the ability of MRI to assess other features such as cell density, blood flow and metabolism which are not specific hallmarks of cancer but which reflect molecular changes. We discuss the future role of MRI in cancer and describe the use of selected quantitative imaging techniques for characterizing tumors that can be translated to clinical applications, particularly in the context of evaluating novel treatments.
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Affiliation(s)
- John C Gore
- Vanderbilt University Institute of Imaging Science AA1105 MCN, Vanderbilt University Nashville, TN 37232-2310, USA.
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