9 results
Intermediation in Private Equity: The Role of Placement Agents
- Matthew D. Cain, Stephen B. McKeon, Steven Davidoff Solomon
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- Journal:
- Journal of Financial and Quantitative Analysis / Volume 55 / Issue 4 / June 2020
- Published online by Cambridge University Press:
- 15 May 2019, pp. 1095-1116
- Print publication:
- June 2020
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Intermediation in private equity involves illiquid investments, professional investors, and high information asymmetry. We use this unique setting to empirically evaluate theoretical predictions regarding intermediation. Using placement agents has become nearly ubiquitous, but agents are associated with significantly lower abnormal returns in venture and real estate funds, consistent with investor capture and influence peddling. However, returns are higher for buyout funds employing a top-tier agent and for first-time real estate and venture funds employing an agent, and are less volatile for agent-affiliated funds, consistent with a certification role. Our results suggest heterogeneous motives for intermediation in the private equity industry.
3 - Principles of irreversible electroporation
- from Section II - Principles of image-guided therapies
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- By Govindarajan Srimathveeravalli, Department of Radiology, Stephen B. Solomon, Department of Radiology
- Edited by Jean-Francois H. Geschwind, Michael C. Soulen
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- Book:
- Interventional Oncology
- Published online:
- 05 September 2016
- Print publication:
- 22 September 2016, pp 13-19
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Summary
Introduction
Electroporation is a phenomenon where cells exposed to a strong external electric field develop nano-scale pores in their plasma membrane. Typically, the pores reseal once the external electric field is removed and the cell continues functioning normally. However, if the number or size of pores formed in the membrane exceeds a certain threshold, the cell is unable to repair the pores, even after removal of the external electric field. This effect has been termed irreversible electroporation (IRE). IRE may be considered a non-thermal ablation technique, as cell death is largely due to electroporation-related factors and is not contingent on sustained changes in temperature. However, this does not completely preclude heating of the treated tissue, as Joule heating-induced damage to tissue during IRE has been seen to occur within a 2–3-mm zone adjacent to the probes. The largely non-thermal mechanism of cell lysis makes IRE an attractive option for the treatment of tumors that are contraindicated for established thermal ablation techniques. As IRE ablation seems unaffected by variations in tissue perfusion and biological heat-sink effects, it has been used to treat hypervascular tumors and lesions adjacent to large blood vessels (Figure 3.1). Unlike thermal ablation techniques, which can denature proteins and completely destroy collagenous structures within the ablation zone, ablation with IRE has been observed to spare the extracellular matrix within the treated regions. This has allowed the safe application of IRE to treat tumors abutting the bile duct or the rectum in patients (Figure 3.1).
IRE presents a new clinical paradigm for the planning and delivery of image-guided ablations. Unlike thermal ablation techniques, where the ablation zone is centered on a single ablation probe, treatment delivery using IRE is typically planned between two monopolar needle electrodes (Figure 3.2). Small variations in the geometry of probe placement can significantly affect the size and shape of the resulting effective ablation zone, affecting the volume of tissue that undergoes destruction (Figure 3.3). The strong electric fields used for IRE ablation can induce neuromuscular activation and affect physiological functions that are sensitive to electrical energy. Therefore, use of IRE in patients has special anesthesia requirements, including the use of a deep paralytic agent to reduce current-induced neuromuscular stimulation.
8 - Imaging in interventional oncology: Role of image guidance
- from Section II - Principles of image-guided therapies
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- By François Cornelis, Department of Radiology, Stephen B. Solomon, Department of Radiology
- Edited by Jean-Francois H. Geschwind, Michael C. Soulen
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- Book:
- Interventional Oncology
- Published online:
- 05 September 2016
- Print publication:
- 22 September 2016, pp 65-76
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Summary
Introduction
Advances in medical imaging have created the opportunity for minimally invasive, image-guided oncologic care by allowing: (1) procedure planning; (2) device delivery; (3) intraprocedure monitoring; and (4) therapy assessment. Although most current image-guided therapy still utilizes standard diagnostic imaging equipment, interventional use of imaging equipment has in fact different priorities compared with diagnostic uses of such equipment. Therefore, interventional procedures prioritize imaging equipment that: (1) provides real-time imaging; (2) lowers radiation dose; and (3) provides greater physician access to the patient. In contrast to diagnostic imaging, lower image quality is an acceptable compromise for real-time imaging for interventional procedures. Patients have already undergone high-quality diagnostic imaging when they are referred to interventional therapies. Moreover, high-quality diagnostic imaging may require more time and more radiation dose than fast imaging of a restricted region of interest as performed for image guidance of interventions.
Although current imaging systems provide some of the required features for interventional procedures, none provides all of them. Ultrasound (US) is a real-time, multiplanar technique, but is limited in terms of detection or tumor visualization. Computed tomography (CT) provides partial access and can be used to guide procedures intermittently, but exposes patients and staff to ionizing radiation. Moreover, CT is primarily a two-dimensional (2D) planar tool; real-time, three-dimensional (3D) imaging is not yet fully integrated into interventional CT applications. Magnetic resonance imaging (MRI) seems to be the most reliable technique, allowing interventions to be performed for tumors that are visible only with MRI, such as in case of soft-tissue tumors, and provides thermal monitoring of ablations, but access to MRI systems is limited and MR tool compatibility is lacking. However, using these techniques, recent intervention-focused improvements have helped broaden the applications of image-guided therapy.
Imaging for procedure planning
The first critical application of imaging in any image-guided procedure or, for that matter, any surgical procedure is in the planning phase. In this application, the most relevant, high-quality diagnostic imaging study available must be evaluated. In many cases, the evaluation requires an assortment of imaging studies. Some may be anatomic studies such as contrast CT or MR, and other studies may be physiologic studies such as positron emission tomography (PET) or single-photon emission computed tomography (SPECT).
27 - Prostate ablations
- from Section IX - Organ-specific cancers – prostate
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- By François Cornelis, Department of Radiology, Jeremy C. Durack, Department of Radiology, Behfar Ehdaie, Department of Urology, Jonathan Coleman, Department of Urology, Stephen B. Solomon, Department of Radiology
- Edited by Jean-Francois H. Geschwind, Michael C. Soulen
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- Book:
- Interventional Oncology
- Published online:
- 05 September 2016
- Print publication:
- 22 September 2016, pp 265-282
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Summary
Introduction
In the last decades, the incidence of prostate cancer tripled to 152 new cases of prostate cancer per 100,000 men in 2013. Among cancer in men, it is the third most common cause of death in men, with 23 per 100,000 men/year. A better understanding of prostate cancer biology and earlier detection with prostate-specific antigen (PSA) screening and imaging have contributed to interest in less invasive alternatives to surgical resection.
Focal tumor ablation has been increasingly used for local control or with curative intent in solid-organ tumors such as kidney, thyroid, breast, liver, and lung. While stimulating thought about ablation application in prostate cancer, clinical application has been limited despite encouraging functional and short-term oncological outcomes. Furthermore, despite evidence that men with low-risk localized prostate cancer may not benefit from treatment in terms of prostate cancer-specific mortality, many men still elect to undergo radical treatment. For these patients, minimally invasive options that could provide oncologic efficacy with little impact on quality of life may be attractive. More importantly, focal ablation of intermediate-risk tumors may enable more men to remain on active surveillance, thereby sparing them the consequent harms associated with radical treatment, including sexual, urinary, and bowel complications.
Prostate ablation is an emerging treatment modality offering promise for local cancer control with reduced morbidity relative to alternatives. The image-guided nature of focal ablation techniques is particularly appealing as preservation of erectile, urinary, and rectal function can be achieved by minimizing damage to the neurovascular bundles, external sphincter, bladder neck, and rectum. The reality, however, is that ablation strategies have not been standardized in the prostate. A trend toward targeted treatments in men with smaller tumor volume and away from whole- or half-gland therapy has been observed. One explanation is that the natural history of the disease is driven by the largest lesion with the highest grade, the so-called “index lesion,” and not by the presence of multiple foci of disease observed in surgical series. Improvements in imaging techniques, particularly magnetic resonance imaging (MRI), now enable visualization of small foci of prostate cancer. Whether focal ablation should play an increasing role in prostate cancer management is a matter of ongoing debate, though clinical outcomes after treatment of smaller-volume disease in other organs have been encouraging.
16 - Colorectal masses: Ablation
- from Section IV - Organ-specific cancers – liver metastases
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- By Elena N. Petre, Department of Radiology, Stephen B. Solomon, Department of Radiology, Constantinos T. Sofocleous, Department of Radiology
- Edited by Jean-Francois H. Geschwind, Michael C. Soulen
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- Book:
- Interventional Oncology
- Published online:
- 05 September 2016
- Print publication:
- 22 September 2016, pp 139-147
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Summary
Introduction
Colorectal cancer (CRC) is the third most frequently diagnosed cancer and the third leading cause of cancer-related death in the USA. About 10–25% of patients present with synchronous liver metastases at the time of primary diagnosis and another 20–25% develop metachronous liver metastases during the course of the disease. Surgical resection of distant CRC metastases may result in improved long-term survival and even cure in a subset of selected patients. The 5-year survival rates after curative resection of liver metastases range from 35% to 58%. However, only 25% of patients with colorectal liver metastases (CLM) are candidates for liver resection, while the majority remain unresectable. Chemotherapy and newer therapies can extend survival of patients with non-resectable CLM up to 24 months.
In recent years, image-guided percutaneous ablation therapies have flourished as alternative treatment options for selected patients with unresectable CLM. Different ablation technologies include radiofrequency, microwave, laser, and cryoablation, that use heat or freezing as a means of causing cell damage and death of the target tumor. More recently, irreversible electroporation (IRE), a non-thermal technology, has been applied for liver tumor ablation, including CLM.
The goal of local tumor ablation is to efficiently destroy the malignant tumor with surrounding margins while minimizing the destruction of non-affected liver. This is an important parameter for patients with low volume of healthy functioning parenchyma as those with underlying cirrhosis or steatohepatitis from prolonged chemotherapy exposure as well as those who have previously undergone extensive liver resection and present for ablation as a salvage therapy for postsurgical recurrences.
The safety and effectiveness of local tumor ablation in patients with CLM have been demonstrated in several uncontrolled studies. Patient survival after percutaneous ablation seems comparable to that of surgical series (up to 55% at 5 years) in selected patients with small-volume disease that can be treated with sufficient margins. This observation may suggest that image-guided ablation could be an equally effective and less morbid alternative to surgery for a subset of selected patients.
Contributors
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- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
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- Book:
- The Cambridge Dictionary of Philosophy
- Published online:
- 05 August 2015
- Print publication:
- 27 April 2015, pp ix-xxx
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7 - Imaging in Interventional Oncology: Role of Image Guidance
- from PART II - PRINCIPLES OF IMAGE-GUIDED THERAPIES
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- By Stephen B. Solomon, Associate Attending Physician, Co-Director, Center for Image-guided Intervention, Memorial Sloan-Kettering Cancer Center, New York, NY
- Edited by Jean-François H. Geschwind, The Johns Hopkins University School of Medicine, Michael C. Soulen, University of Pennsylvania School of Medicine
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- Book:
- Interventional Oncology
- Published online:
- 18 May 2010
- Print publication:
- 15 September 2008, pp 78-85
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Summary
Advances in medical imaging have created the opportunity for minimally invasive, image-guided oncologic care. Through the 1980s and 1990s, as diagnostic scan quality improved, it became obvious to make the transition from using imaging tools simply for diagnostic use to roles that could aid in intervention. As an interventional tool, medical imaging allows visualization of anatomic targets inside the body without requiring direct, open surgical visualization. When combined with advances in medical device design and device miniaturization, medical imaging can guide devices to targets for therapy without large incisions. These less invasive, image-guided procedures offer patients an opportunity for faster, less complicated recoveries.
Interventional use of imaging equipment has different priorities compared with diagnostic uses of imaging equipment. In general, generating the highest quality image is most important for diagnosis. This means that taking more imaging time or applying more radiation are acceptable “costs” for diagnostic imaging. In contrast, patients come to interventional procedures already having undergone high-quality diagnostic imaging. For interventional procedures, in general, lower-quality imaging is an acceptable compromise for real-time imaging with lower radiation dose. Interventional procedures, therefore, prioritize imaging equipment that (1) provides real-time imaging, (2) lowers radiation dose and (3) provides greater physician access to the patient. Although most current image-guided therapy still utilizes standard diagnostic imaging equipment, more and more imaging equipment is being customized for the particular needs of interventional procedures. These future intervention-focused improvements will help broaden the applications of image-guided therapy.
Comparing Bloodstream Infection Rates: The Effect of Indicator Specifications in the Evaluation of Processes and Indicators in Infection Control (EPIC) Study
- Barbara I. Braun, Stephen B. Kritchevsky, Linda Kusek, Edward S. Wong, Steven L. Solomon, Lynn Steele, Cheryl L. Richards, Robert P. Gaynes, Bryan Simmons, Evaluation of Processes and Indicators in Infection Control (EPIC) Study Group
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 27 / Issue 1 / January 2006
- Published online by Cambridge University Press:
- 21 June 2016, pp. 14-22
- Print publication:
- January 2006
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Objective.
Bloodstream infection (BSI) rates are used as comparative clinical performance indicators; however, variations in definitions and data-collection approaches make it difficult to compare and interpret rates. To determine the extent to which variation in indicator specifications affected infection rates and hospital performance rankings, we compared absolute rates and relative rankings of hospitals across 5 BSI indicators.
Design.Multicenter observational study. BSI rate specifications varied by data source (clinical data, administrative data, or both), scope (hospital wide or intensive care unit specific), and inclusion/exclusion criteria. As appropriate, hospital-specific infection rates and rankings were calculated by processing data from each site according to 2-5 different specifications.
Setting.A total of 28 hospitals participating in the EPIC study.
Participants.Hospitals submitted deidentified information about all patients with BSIs from January through September 1999.
Results.Median BSI rates for 2 indicators based on intensive care unit surveillance data ranged from 2.23 to 2.91 BSIs per 1000 central-line days. In contrast, median rates for indicators based on administrative data varied from 0.046 to 7.03 BSIs per 100 patients. Hospital-specific rates and rankings varied substantially as different specifications were applied; the rates of 8 of 10 hospitals were both greater than and less than the mean. Correlations of hospital rankings among indicator pairs were generally low (rs = 0-0.45), except when both indicators were based on intensive care unit surveillance (rs = 0.83).
Conclusions.Although BSI rates seem to be a logical indicator of clinical performance, the use of various indicator specifications can produce remarkably different judgments of absolute and relative performance for a given hospital. Recent national initiatives continue to mix methods for specifying BSI rates; this practice is likely to limit the usefulness of such information for comparing and improving performance.
Preventing Central Venous Catheter-Associated Primary Bloodstream Infections: Characteristics of Practices Among Hospitals Participating in the Evaluation of Processes and Indicators in Infection Control (EPIC) Study
- Barbara I. Braun, Stephen B. Kritchevsky, Edward S. Wong, Steve L. Solomon, Lynn Steele, Cheryl L. Richards, Bryan P. Simmons, Evaluation of Processes and Indicators in Infection Control (EPIC) Study Group
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 24 / Issue 12 / December 2003
- Published online by Cambridge University Press:
- 02 January 2015, pp. 926-935
- Print publication:
- December 2003
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Objectives:
To describe the conceptual framework and methodology of the Evaluation of Processes and Indicators in Infection Control (EPIC) study and present results of CVC insertion characteristics and organizational practices for preventing BSIs. The goal of the EPIC study was to evaluate relationships among processes of care, organizational characteristics, and the outcome of BSI.
Design:This was a multicenter prospective observational study of variation in hospital practices related to preventing CVC-associated BSIs. Process of care information (eg, barrier use during insertions and experience of the inserting practitioner) was collected for a random sample of approximately 5 CVC insertions per month per hospital during November 1998 to December 1999. Organization demographic and practice information (eg, surveillance activities and staff and ICU nurse staffing levels) was also collected.
Setting:Medical, surgical, or medical-surgical ICUs from 55 hospitals (41 U.S. and 14 international sites).
Participants:Process information was obtained for 3,320 CVC insertions with an average of 58.2 (± 16.1) insertions per hospital. Fifty-four hospitals provided policy and practice information.
Results:Staff spent an average of 13 hours per week in study ICU surveillance. Most patients received nontunneled, multiple lumen CVCs, of which fewer than 25% were coated with antimicrobial material. Regarding barriers, most clinicians wore masks (81.5%) and gowns (76.8%); 58.1% used large drapes. Few hospitals (18.1%) used an intravenous team to manage ICU CVCs.
Conclusions:Substantial variation exists in CVC insertion practice and BSI prevention activities. Understanding which practices have the greatest impact on BSI rates can help hospitals better target improvement interventions.