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Adding Bevacizumab to Initial Glibolastoma Treatment does not Improve …

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According to a new study, glioblastoma (GBM) which is the most common principal malignant adult brain tumor and, regardless of treatment improvements in past years, the mean survival of patients registered in clinical trials is less than 16 months with few patients living beyond five years. GBM tumors are categorized by angiogenesis, which is the formation of new blood vessels that support tumor growth stimulated by the GBM-produced vascular endothelial growth factor A (VEGF-A). Bevacizumab is a monoclonal antibody that seeks out VEGF-A production to obstruct the growth of tumor-based blood vessels. "Clinical trials evaluating the addition of bevacizumab to standard treatment for recurrent glioblastoma demonstrated clinical benefit and led to the drug's U.S. Food and Drug Administration approval for this indication.” said Radiation Therapy Oncology Group 0825 principal investigator and professor of neuro-oncology at The University of Texas MD Anderson Cancer Center in Houston, Mark Gilbert, M.D. “Additionally, compelling preclinical data suggest that anti-angiogenic targeted therapies may normalize the tumor's rapidly forming and underdeveloped blood vessels, resulting in improved oxygen and chemotherapy delivery to the tumor and potentially enhanced radiotherapy (RT) and chemotherapy treatment.” Six hundred and twenty-one adult study participants noted in the study's final analysis were registered in the multicenter trial and randomized into one of two study arms, with treating physicians blinded to treatment assignment. All participants were treated with standard-of-care (60 Gy RT and daily temozolomide chemotherapy). Bevacizumab (experimental arm) or a placebo (standard treatment arm) was delivered starting at week 4 of RT and continued every 2 weeks until 1) disease progression, or 2) severe treatment-related toxicity, or 3) completion of adjuvant therapy. At the time of disease progression, the treatment arm was unblinded allowing for follow on treatment with or without bevacizumab. The researchers reported data at an average follow-up time of 20.5 months, which showed no statistical difference in overall survival between the two study arms (average 16.1 months for the standard-treatment arm compared to 15.7 months for the bevacizumab arm). While there was a difference in progression-free survival (PFS) (7.3 months for the placebo arm compared to 10.7 months for the bevacizumab arm), the pre-established level of benefit for PFS was not achieved. "The relevant result is that the upfront use of bevacizumab is not indicated. It's important to emphasize that the question we sought to answer was whether administering bevacizumab as first-line treatment improved survival; the cross-over component allowed comparison of risk and benefit of early versus late treatment We now know by giving it late you delay the risk of toxicity, and that may be relevant,” said Gilbert. Due to the fact that bevacizumab is known to puzzle magnetic resonance imaging (MRI) examination results used to evaluate GBM tumor progression, RTOG 0825 researchers integrated a "net clinical benefit" component in the trial design to conclude if quality of life, symptom burden and neurocognitive function test results support MRI-reported stable or improved disease status. Over 80 percent of study participants conceded to take part in the net clinical benefits component, which revealed a higher decline of cognitive function for patients in the bevacizumab arm as opposed to those in the placebo arm. "While we found a difference in progression-free survival in the bevacizumab arm, there was an overall increase in symptom burden and decline in neurocognitive function and some measures of quality of life over time comparing the patients receiving bevacizumab with those on placebo," noted Gilbert. "Study participants' consent allowing the collection of tumor tissue and blood samples, as well as imaging examination, longitudinal symptom, QOL, and neurocognitive function data provides RTOG investigators a rich archive of data to support ongoing investigations of potential molecular markers to identify subgroups of patients who may benefit from early bevacizumab," said study co-principal investigator and chair of the Radiation Therapy Oncology Group Brain Tumor Committee and a professor of radiation oncology at the University of Maryland School of Medicine, Minesh Mehta, M.D. "The RTOG 0825 results provide important insight about the use of anti-angiogenic therapies with standard first-line treatment. he unprecedented collection of specimens and associated outcome data will provide significant future information as we investigate new treatment strategies for these patients within NRG Oncology. I thank our ECOG and NCCTG colleagues for their significant trial support,” said Radiation Therapy Oncology Group chairman, co-author and executive director of the Winship Cancer Center at Emory University in Atlanta, Walter J. Curran Jr., ... Read more

MRI Offers Advancements in Treatment for Chronic …

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Scientists at The University of Nottingham have recently constructed detailed structural and functional 'maps' of the human kidney made using advanced scanning technology. The research, funded with £107,623 from the Dr Hadwen Trust, a non-animal biomedical research charity, aims to further expand medical understanding on how the kidneys operate, with the main goal of leading to better monitoring and treatment for chronic kidney disease. The study will be the very first of its kind to employ magnetic resonance imaging to examine the role which oxygen plays in keeping the human kidney healthy. The study, headed led by Dr Sue Francis from the University's Sir Peter Mansfield Magnetic Resonance Centre and is in collaboration with Professor Chris McIntyre from the University's School of Medicine. "Current tests for chronic kidney disease can be very invasive and patients may need to return to the hospital on a number of occasions. The aim of this project is to produce a set of non-invasive measurements that we can produce in a single, one-hour scanning session that can assess the blood flow and oxygenation of the kidney and which could eventually be rolled out in a clinical setting to benefit patients,” said Francis. The kidneys play a crucial role in the human body, sifting waste products from the blood before changing them to urine. They also help to maintain blood pressure, regulate chemical levels in the body, keep bones healthy by producing a type of vitamin D, and stimulate the production of red blood cells. However, health conditions such as diabetes and high blood pressure can have a tremendous impact on how efficiently the kidneys can operate and can lead to chronic kidney disease, causing tiredness, water retention, weight loss, and a loss of appetite. As of today, the disease is diagnosed by a blood test which measures the GFR, glomerular filtration rate, which is the quantity of blood that is filtered through the kidneys. In more serious kidney conditions, a renal biopsy may need to be performed, which involves removing a small sample of tissue from the kidney. “Current methods can only offer a fairly crude picture of what is happening in the kidneys and how that is changing over time. For example, if one kidney is doing most of the work it can be difficult to tell and taking just a small sample of tissue from one area of the kidney may not be representative of the organ as a whole,” noted Francis. The research will instead employ magnetic resonance imaging (MRI), powered by a 3 Tesla magnet, to scan the kidney and construct a detailed picture of perfusion in the kidney, the manner in which blood is transported to and flows through the organ. Additionally, it will measure the metabolic rate of oxygen, how oxygen is consumed within the kidney, which has not been done before using MR imaging. The research aims to develop novel MRI methods, and utilize these methods in healthy volunteers to document and study the kidney's response to oxygen and CO2 changes to evaluate how the kidney behaves under stress which mimics diseased kidneys. For the next phase of the study, the researchers will scan 20 patients with diabetic nephropathy (kidney disease caused by diabetes) in a proposal to prove the effectiveness of their techniques. The scanning technique could be used to track the progression of a patient's disease and to observe the effect and effectiveness of drugs being used to treat the ... Read more

Novel Imaging Method Can Diagnose Common Heart …

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A new imaging technique used for measuring blood flow in the heart and vessels can diagnose a common congenital heart abnormality, bicuspid aortic valve, and could very well lead to better prediction of any future complications. A Northwestern Medicine team reported their discoveries in the journal Circulation. In the study, the researchers exhibited, for the first time a previously unknown relationship between heart valve abnormalities, blood flow changes in the heart, and aortic disease. They revealed that blood flow changes were caused by certain kinds of abnormal aortic valves, and they were able to directly link blood flow blueprints with aortic diseases. "Blood flow in patients with bicuspid aortic valves was significantly different compared to that in patients with normal valves. We now have direct evidence that bicuspid valves induce changes in blood flow and that the type of flow abnormality may contribute to the development of different expressions of heart disease in these patients,” said senior author and associate professor of radiology at Northwestern University Feinberg School of Medicine, Michael Markl. Bicuspid aortic valve is a heart condition in which the aortic valve only has two leaflets, instead of the usual three. It affects around one to two of every 100 Americans and is the most prevalent congenital cardiovascular abnormality. Regardless of the non-existence of symptoms, the condition can lead to major and potentially life-threatening complications, including enlargement of the blood vessel (aneurysm) and rupture. However, it is not known which patients are at the highest risk for complications and whether the condition's source is genetic or associated to changes in blood flow. The 4D flow MRI (magnetic resonance imaging) employed during the course of the study has the potential for better predictive ability. "The study demonstrated that new imaging techniques may help to determine patient-specific changes in blood flow to better understand which regional areas of the aorta are most prone to developing disease," said Markl. "In addition, the knowledge of abnormal blood flow patterns could be important to better identify patients at risk for the development of heart disease." Markl's team was quite taken aback when they saw such a clear distinction between individual expressions of aortic complications for different types of congenital valve disease. While the present data demonstrates evidence of this association, long-term observational studies are required to better understand the potential of 4D flow MRI to improve disease prediction ability. A longitudinal follow-up study in patients with bicuspid aortic valves is currently being carried out at Northwestern. "Ultimately, we hope that this imaging technique will facilitate early identification of high-risk blood flow patterns associated with progressive aortic enlargement, improving the allocation of health care resources in caring for patients with this prevalent condition," Markl ... Read more

Combination of MRI/Ultrasound Imaging Enhances …

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A powerful combination of MRI-ultrasound imaging system can lead to fewer biopsies and overall improved treatment decisions for prostate cancer patients. The technology, called UroNav®, merges images from magnetic resonance imaging (MRI) with ultrasound to construct a detailed, three-dimensional view of the prostate. This enhanced view aids physicians in performing biopsies with much higher precision, and increases prostate cancer detection, according to Loyola University Medical Center prostate cancer surgeon Gopal Gupta, MD. Loyola is the first hospital in Illinois to employ such a system. "This is revolutionizing how we diagnose prostate cancer and make treatment decisions. When prostate cancer is suspected due to results of a PSA blood test or digital rectal exam, a physician performs a prostate biopsy. This typically involves sticking a needle into 12 different areas of the prostate. However, this traditional method can miss a tumor. Consequently, the physician either will falsely conclude the patient does not have cancer, or will perform one or more additional biopsies to find the suspected tumor,” said Gupta. In the new fusion technique, the patient receives a MRI exam prior to undergoing a biopsy. The MRI can detect lesions in the prostate that may be cancerous. During the biopsy, the MR image is merged with ultrasound imaging. The system applies GPS-type technology to guide the biopsy needle to the lesions detected by the MRI, leading to considerably fewer needle biopsies. "Compared with traditional biopsy techniques that randomly sample the prostate, the new technology helps prevent physicians from missing hard-to-find and often aggressive prostate cancers. This potentially will help provide greater certainty regarding the extent and aggressiveness of the disease. And it could enable patients to avoid multiple and unnecessary repeat prostate biopsies,” notes Gupta. “Traditional biopsies lack precision, which can lead to either too much treatment or not enough treatment. For example, if the biopsy fails to identify an aggressive tumor, the patient may be under treated. Conversely, a patient may undergo surgery or radiation for a tumor that likely would grow too slowly to endanger the patient during his expected lifetime,” Gupta added. Biopsies guided by MRI/ultrasound fusion will allow physicians and patients to opt for active observation, when suitable. Under active observation, the patient avoids having surgery or radiation and instead undergoes periodic digital rectal exams, PSA tests and ultrasounds to see whether the cancer is growing. “MRI/ultrasound fusion is the next generation of MRI evaluation in the fight against prostate cancer," said Loyola radiologist Ari Goldberg, MD, PhD. "These leading-edge imaging technologies will improve patient care by enabling physicians to detect and characterize abnormalities at the earliest possible stages. The techniques also will give physicians better insight into whether, for example, a cancer has spread, and how effective a treatment has been,” said chair of Loyola's Department of Radiology, Scott Mirowitz, ... Read more

Radiation-free Imaging Method Efficiently Diagnoses …

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According to a study recently published in The Lancet Oncology, researchers from Stanford University School of Medicine in California tested a new whole-body diffusion-weighted magnetic resonance imaging (MRI) technique. The imaging method uses ferumoxytol, an iron supplement, to significantly improve the visibility of tumors. Ferumoxytol consists of tiny superparamagnetic iron oxide particles that can be detected when using MRI. Typical imaging systems, such as PET and CT scans, are used to evaluate the development of cancer in children. However, these imaging techniques can expose children to radiation that raises their risk of secondary cancers later in life. Now, this new research has outlined a novel whole-body imaging technique that could eliminate such a risk. The research team, led by Dr. Heike Daldrup-Link, recognizes that computed tomography (CT) and F-fludeoxyglucose (18F-FDG) positron emission tomography (PET)/CT scans are the prime methods employed to see what stage cancers are at and to assess the best treatment plan. However, Daldrup-Link notes previous research has shown the secondary cancer risks linked with these techniques. According to the study background, ionizing radiation, high frequency radiation that has enough energy to damage cells' DNA, in early childhood has been demonstrated to triple the risk of lifetime cancer, as opposed to adults exposed to the radiation from the age of 30. Moreover, the researchers note that growing radiation exposure from diagnostic CT scans may almost triple the risk of secondary leukemia and brain cancer later in life. Daldrup-Link illuminates the point that children are much more sensitive to radiation than adults are, and are more likely to experience secondary cancers because they will live for a longer period following exposure. The researchers wanted to see how their new whole-body MRI technique, which uses no radiation exposure, would match up in terms of diagnostic precision with the standard F-FDG PET/CT approach. The investigators utilized both the whole-body MRI and F-FDG PET/CT to scan 22 children and young adults aged between 0 and 33 years who had malignant lymphomas and sarcomas. Mean radiation exposure was verified as zero for the whole-body MRI technique, while the F-FDG PET/CT method exposed patients to 12.5 millisieverts (mSv). The investigators discovered that the diagnostic accuracy of the whole-body MRI technique was 97.2%, as opposed to 98.3% in the F-FDG PET/CT technique. The whole-body MRI also exhibited similar sensitivities and specificities to the F-FDG PET/CT, at 93.7% vs. 90.8% and 97.7% vs. 99.5%, respectively. "Present techniques used for diagnosis and treatment, albeit effective, might bear certain risks and thus do not meet our high standards on patient care. This new imaging test might solve this conundrum of the need for diagnostic cancer staging procedures and concurrent risk of secondary cancer development later in life,” the researchers commented on their findings. Yet, in a comment piece connected to the study, Thomas C. Kwee, of the University Medical Centre Utrecht in the Netherlands, notes that “although the new whole-body MRI technique has shown success in this study, further work is needed before it can become a clinical alternative to F-FDG PET/CT." Daldrup-Link acknowledges such claims and states that the research team plans to conduct and gather further research regarding the study. She noted the team has already formed a collaboration with six centers in the US, including the University of California, San Francisco, and Stanford University, in order to test the new MRI imaging method against radiotracer-based staging examinations. "We are in the process of applying for funding at the moment and if all goes well, might be able to start the multi-center trial this fall. We already received requests from two centers in Europe who want to join in as well," said ... Read more

Single Chip Device Offers Real-time 3D Images inside …

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Researchers from the Georgia Institute of Technology have creating the technology for a catheter-based device that would provide insightful, real-time, three-dimensional (3D) imaging from inside the heart, coronary arteries, and peripheral blood vessels. With its all encompassing imaging, the novel device could better aid surgeons when working in the heart, and possibly allow more of patients' clogged arteries to be cleared without major surgery. The device incorporates ultrasound transducers with processing electronics on a single 1.4 millimeter silicon chip. On-chip processing of signals permits data from more than a hundred elements on the device to be transmitted using just 13 tiny cables, enabling it to easily travel through circuitous blood vessels. The insightful images produced by the device would offer extensively more information than current cross-sectional ultrasound could or can. Researchers have developed and tested a model able to present image data at 60 frames per second, and plan next to perform animal studies that could result in commercialization of the device. "Our device will allow doctors to see the whole volume that is in front of them within a blood vessel. This will give cardiologists the equivalent of a flashlight so they can see blockages ahead of them in occluded arteries. It has the potential for reducing the amount of surgery that must be done to clear these vessels,” said, professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology, F. Levent Degertekin. Findings and details of the research were published online in the February 2014 issue of the journal IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. Research leading to the development of the device was supported and funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of the National Institutes of Health. "If you're a doctor, you want to see what is going on inside the arteries and inside the heart, but most of the devices being used for this today provide only cross-sectional images. If you have an artery that is totally blocked, for example, you need a system that tells you what's in front of you. You need to see the front, back and sidewalls altogether. That kind of information is basically not available at this time,” said Degertekin. The single chip device integrates capacitive micromachined ultrasonic transducer (CMUT) arrays with front-end CMOS electronics technology to provide 3D intravascular ultrasound (IVUS) and intracardiac echography (ICE) images. The dual-ring array includes 56 ultrasound transmit elements and 48 receive elements. When gathered, the donut-shaped array is just 1.5 millimeters in diameter, with a 430-micron center hole to house a guide wire. Power-saving circuitry in the array shuts down sensors when they are no longer required, enabling the device to function with just 20 milliwatts of power, decreasing the amount of heat generated inside the body. The ultrasound transducers operate at a frequency of 20 megahertz (MHz). Imaging devices working from within blood vessels can offer higher resolution images than devices working from outside the body because they can function at higher frequencies. However, operating inside blood vessels calls for devices that are tiny and flexible enough to travel through the circulatory system. They must also be able to operate in blood. Performing such a task requires a large number of factors to transmit and receive the ultrasound information. Transmitting data from these factors to external processing equipment could involve many cable connections, potentially limiting the device's ability to be threaded inside the body. Degertekin and his collaborators have taken not and have addressed such a challenge by miniaturizing the elements and carrying out some of the processing on the probe itself, allowing them to attain what they believe are clinically-useful images with only 13 cables. "You want the most compact and flexible catheter possible. We could not do that without integrating the electronics and the imaging array on the same chip,” Degertekin explained. Based on their mock-model, the researchers anticipate to perform animal trials to showcase the device's potential applications. They ultimately expect to license the technology to an established medical diagnostic firm to conduct the clinical trials necessary to obtain FDA approval. In the meantime, Degertekin hopes to develop a version of the device that could guide interventions in the heart under magnetic resonance imaging (MRI). Other plans include further reducing the size of the device to place it on a 400-micron diameter guide ... Read more

Device Shaped like Credit-card can Analyze Biopsy, …

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The results of pancreatic cancer are often devastatingly grave, with at least 94 percent of patients dying within five years from initial diagnosis. And in 2013 pancreatic cancer was ranked as one of the top 10 deadliest cancers. Regular screenings for breast, colon, and lung cancers have improved treatment and outcomes for patients with these diseases, mainly because the cancer can be detected and handled early. However, because little is known about how pancreatic cancer behaves and develops patients usually receive a diagnosis when it's already too late. Therefore, University of Washington scientists and engineers are developing a cost-effective device that could significantly aid pathologists diagnose pancreatic cancer sooner and faster. The initial model can perform the basic steps for processing a biopsy, relying on fluid transport in place of human hands to process the tissue. The team presented its preliminary findings this month (February 2014) at the SPIE Photonics West conference and recently filed for exclusive rights for this first-generation device and future technology advancements. "This new process is expected to help the pathologist make a more rapid diagnosis and be able to determine more accurately how invasive the cancer has become, leading to improved prognosis," said UW research professor of mechanical engineering and director of the department's Human Photonics Laboratory, Eric Seibel. The novel device would fundamentally mechanize and streamline the manual, time-consuming process a pathology lab undergoes to diagnose cancer. Presently, a pathologist extracts a biopsy tissue sample, then sends it to the lab where it's cut into thin slices, stained, and set on slides, then analyzed optically in 2-D for abnormalities. “The UW's technology would process and analyze whole tissue biopsies for 3-D imaging, which offers a more complete picture of the cellular makeup of a tumor,” said UW postdoctoral researcher in bioengineering who is the lead author on a related paper, Ronnie Das. "As soon as you cut a piece of tissue, you lose information about it. If you can keep the original tissue biopsy intact, you can see the whole story of abnormal cell growth. You can also see connections, cell morphology and structure as it looks in the body," he explained. The research team is in the process of constructing a thick, credit card-sized, flexible device out of silicon that permits a piece of tissue to pass through tiny channels and undergo a sequence of steps that duplicate what occurs on a much larger scale in a pathology lab. The device binds the characteristics of microfluidics, which allows tissue to move and stop with ease through small channels without needing to apply a considerable amount of external force. It also keeps clinicians from having to handle the tissue; instead, a tissue biopsy taken with a syringe needle could be deposited directly into the device to begin processing. Researchers note that this is the very first time material larger than a single-celled organism has successfully moved in a microfluidic device. This could have implications across the sciences in automating analyses that usually are carried out by humans. Das and Chris Burfeind, a UW undergraduate student in mechanical engineering, tailored the device to be simple to manufacture and use. They first constructed a mold using a petri dish and Teflon tubes, then poured a viscous, silicon material into the mold. The outcome is a small, transparent instrument with textbook channels that are both curved and straight. The researchers have utilized the device to process a tissue biopsy one step at a time, following the same stages as a pathology lab would. In the future they hope to integrate all of the steps into a more forceful device, including 3-D imaging, then construct and optimize it for use in a lab. Future repetitions of the device could include layers of channels that would allow more analyses on a piece of tissue without adding more bulk to the device. “The technology could be used overseas as an over-the-counter kit that would process biopsies, then send that information to pathologists who could look for signs of cancer from remote locations. Additionally, it could potentially reduce the time it takes to diagnose cancer to a matter of minutes, “said ... Read more

HRCT Scans Can Spot Fatal Lung Disease…

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Based on a new study recently published in The Lancet Respiratory Medicine, people who have suspected idiopathic pulmonary fibrosis (IPF) without typical patterns on high resolution computed tomography scans could in the future be spared the considerable risks of lung biopsy and be given a strong diagnosis of IPF predicated on clinical and radiological findings alone. Studies from the UK and USA suggest IPF is becoming more prevalent. There are an approximated 5000 new cases in the UK annually and IPF causes more annual deaths than either leukaemia, ovarian cancer, or kidney cancer. In the USA, around 50,000 new cases are diagnosed every year and as many as 40,000 Americans die from IPF each year, the same number as die of breast cancer.   IPF causes progressive scarring of lung tissue, which eventually obstructs the lungs from being able to supply the body with sufficient oxygen. IPF has no known cure and most people live only 3 to 5 years following diagnosis. Suitable treatment is difficult due to the fact that a definitive diagnosis often requires a lung biopsy.   HRCT scans of the lungs can identify typical 'honeycombing pattern' of lung scarring and damage to the air sacs known as usual interstitial pneumonia (UIP) in people with IPF. In a patient with progressive breathlessness who has no major environmental exposures leading to pulmonary fibrosis, or evidence of collagen vascular diseases, the UIP pattern on HRCT is indicative of IPF. When patients suspected to have IPF do not have the definitive UIP pattern on HRCT images, international guidelines suggest a surgical lung biopsy to make a solid diagnosis of IPF in such patients.   "Surgical lung biopsy is associated with substantial risks and many patients are too elderly, sick, and/or have comorbid conditions to tolerate the invasive procedure", explains Professor Ganesh Raghu from the University of Washington Medical Center, Seattle, USA who led the research.   "A confident diagnosis of IPF is needed to ensure that patients are well informed of the poor prognosis associated with IPF, are treated with the most appropriate therapies, consider participation in clinical trials of new therapies, and to identify those most suitable for lung transplantation."   In this retrospective study of 315 patients aged 40 years and older with little or no (5% or less) honeycombing on high resolution CT, 79 (94%) of 84 patients who had a high-resolution pattern of possible UIP diagnosed by an expert radiologist and pathologist had histopathological UIP confirmed after analysis of lung biopsy samples.   "Our findings suggest that when a team of multidisciplinary experts in interstitial lung disease at a regional center (that includes a chest radiologist and a pulmonologist) work together to interpret possible UIP pattern on high-resolution CT in a patient suspected to have IPF, surgical lung biopsy might not be necessary to reach a diagnosis of IPF,” said Raghu.   "Since the patients enrolled in our study were a highly selected cohort of patients suspected to have IPF and referred to regional sites for consideration of participation in a clinical trial, the findings from our study must not be extrapolated for all patients demonstrating the possible UIP pattern on HRCT images interpreted by general pulmonologists and radiologists in the community,” he concludes   "The results will also help to provide clarity about treatment options for a greater number of patients and increase the pool of patients suitable for inclusion in clinical trials of new therapies…In the modern era with optimal high-resolution CT imaging and thoracic radiologists familiar with interpretation of interstitial lung disease patterns through participation in multidisciplinary meetings, the role of lung biopsy assessment might diminish further. In future, combination of high-resolution CT with new noninvasive biomarkers and functional imaging could be used to better define phenotypes of fibrotic interstitial lung disease,” wrote Dr Simon Hart from Hull York Medical School in the ... Read more

Cardiac Tests Result in More Tests, With Little Answers…

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A recent study analysis of more than 220 US hospitals demonstrates wide variation in the use of noninvasive imaging in patients admitted to the emergency department with chest pain. Regardless of the variation, hospitals with high rates of imaging did not have lower MI readmission rates than those with lower rates of noninvasive cardiac imaging. Yet patients treated at hospitals that were frequent users of noninvasive imaging were more likely to be admitted to the hospital and to undergo coronary angiography. Our experience is that there are a lot of different approaches being employed by hospitals around the country, some with protocol-based chest-pain centers and others with more ad hoc approaches. And it seems like there is much less discretion in terms of patients who would merit imaging and how best to apply it. We wanted to get some perspective on how much variation there was and whether there was any relationship between the variation and patient outcomes,” said senior investigator from Yale University School of Medicine, New Haven, CT, Dr. Harlan Krumholz. According to Krumholz the study, recently published online February 10, 2014 in JAMA: Internal Medicine, was meant to offer some data on the nationwide assessment of patients with suspected ischemic heart disease, particularly those with acute coronary syndromes. These patients are often difficult to track because they can be lost to follow-up once they enter into the hospital. The current analysis is predicated on data from the PREMIER database of 2700 acute-care hospitals in the US. All in all, 549 078 patients from 224 hospitals were included in the study, and the use of noninvasive imaging ranged from 0.2% to 55.7%. When the hospitals were stratified by quartiles (Q), the use of noninvasive testing was performed 6.0%, 15.9%, 23.5%, and 34.8% in Q1, Q2, Q3, and Q4, respectively. Myocardial perfusion imaging and stress echocardiograms were the most frequently employed imaging tests. In total, 80.4% of the 113 602 imaging tests performed were myocardial perfusion tests, 16.6% were echocardiograms, and 1.2% were computed tomography coronary angiograms (CTCAs). "We found a remarkable variation in the use of imaging, which is an expensive intervention, and its use was strongly linked to what happened to the patient subsequently. The testing cascade has been discussed in other articles, but this is more proof that the more expensive tests you do the more likely you are to pursue additional tests,” said Krumholz. When compared with those in Q1, hospitals with the highest rates of imaging (Q4) were more likely to admit patients and conduct coronary angiography. Hospitals with lower rates of imaging performed angiography in 1.2% of patients as opposed to 4.9% in patients treated at hospitals with higher use of noninvasive imaging. The rate of coronary revascularization was also higher among patients treated at hospitals with higher rates of noninvasive imaging. Yet, in terms of revascularizations per imaging study and revascularizations per angiogram, hospitals in Q1 had significantly better yield than those in Q4. In spite of the differences in care among hospitals more likely to use imaging, there was no difference in the patients readmitted to hospital within the month or the following month. "We couldn't find any evidence that patients are being benefited by the approach," said Krumholz, referring to the higher rates of imaging at some hospitals. “A lot of hospitals don't have any feedback in terms of where they stand in relationship to other hospitals with their use of noninvasive imaging tests. In analyzing the patient characteristics and hospital factors, the group also found that nearly 25% of the between-hospital variation is attributable to institutional factors and not the types of patients treated. Regarding best clinical practices, the study was not designed to determine whether imaging was appropriate, but the researchers contend that patient-case mix would unlikely account for the variation in cardiac imaging rates,” he added. In an accompanying article, Drs Ezra Amsterdam and Edris Aman from the University of California, Davis point out that accelerated diagnostic protocols (ADPs) involve identifying low-risk patients based on clinical stability, a normal ECG, and a negative biomarker test. Predischarge testing is then used to identify patients for early discharge, and this could include anything from an exercise treadmill test to CCTA. "At the University of California, Davis, Medical Center in Sacramento, we practice physician discretion in selecting patients for predischarge testing. In more than 500 patients discharged directly from the unit after evaluation consisting of normal results of electrocardiograms and cardiac troponin tests, there has been only one adverse cardiac event (0.2%) at the 30-day follow-up,” they write. However, such tactics depends on attaining a detailed family history, an accurate assessment of the ECG, and a reliable assay for cardiac troponin, as well as the willingness of clinicians to implement such an algorithm, especially given the hazards of a missed acute coronary ... Read more

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