RSNA 2009 Registration Opens Tomorrow for Members
RSNA 2009 registration opens tomorrow, Wednesday, April 29, for RSNA members.
EARLY REGISTRATION gives you:
- The best selection of RSNA official hotels
- Free meeting registration
For annual meeting updates, as well as an electronic PDF copy of the Advance Registration and Housing brochure, go to RSNA.org/Register.
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Leading the News
Research
Technology
Medical-Legal Issues
Clinical Practice
Leading the News
FDA Convenes Rare Meeting to Discuss Complaints on Device Approval
Dr. Donna-Bea Tillman, director of the FDA's Office of Device Evaluation (ODE), called an internal meeting on April 22 that included all scientists within the ODE. The meeting was reportedly intended to address concerns raised by nine scientists that the agency approved medical devices that could put patients at risk, despite significant and often unanimous objections from scientific reviewers. Device types cited by the scientists include imaging equipment used to detect breast cancer and certain orthopedic devices. Dr. Tillman's decision to call the meeting follows a number of letters and memorandums sent by the scientists to President Obama and the agency's principal deputy commissioner, Dr. Joshua Sharfstein. A congressional investigation and a recent Government Accountability Office report have both echoed concerns regarding the FDA's device approval office. As a result, Congress is expected to propose legislation that will ask the Institute of Medicine to investigate concerns surrounding the device division.
From "Rare FDA Meeting to Discuss Complaints on Device Approval"
New York Times (04/22/09) Harris, Gardiner
Research
Researchers Compare Diffusion-Weighted MRI With Contrast-Enhanced MRI for the Characterization of T1 Hyperintense Renal Lesions
Dr. Sooah Kim of the New York University Medical Center Department of Radiology and colleagues recently found that the performance of diffusion-weighted (DW) imaging was equivalent to that of enhancement ratio in the characterization of T1 hyperintense renal lesions, with both methods having lower sensitivity than image subtraction without reaching significance. Kim and colleagues reached this conclusion following a study, published online in Radiology, in which two independent observers retrospectively assessed MR images in 41 patients with non-fat-containing T1 hyperintense renal lesions. In all, 64 lesions were assessed, including 38 benign T1 hyperintense cysts and 26 renal cell carcinomas. When data was pooled from both independent observers, area under the receiver operating characteristic curve, sensitivity, and specificity were 0.846, 71 percent, and 91 percent, respectively, for DW imaging and 0.865, 65 percent, and 96 percent, respectively for enhancement ratio, compared to 0.861, 83 percent, and 89 percent, respectively, for subtraction.
From "T1 Hyperintense Renal Lesions: Characterization With Diffusion-Weighted MR Imaging Versus Contrast-Enhanced MR Imaging"
Radiology Online (04/20/09) Kim, Sooah; Jain, Monica; Harris, Andrew B.
18F-FDG PET/CT Aids Restaging of Esophageal Cancer Following Surgical Resection and Radiotherapy
Whole body 18F-FDG PET/CT is effective in detecting relapse of esophageal cancer after surgical resection and radiotherapy, according to a recent study conducted by Minann PET Center Dr. L Sun and colleagues. Additionally, the researchers found that 18F-FDG PET/CT could have a significant clinical impact on the management of esophageal cancer by influencing clinical restaging and salvage treatment of patients.
From "Clinical Usefulness of 18F-FDG PET/CT in the Restaging of Esophageal Cancer After Surgical Resection and Radiotherapy"
World Journal of Gastroenterology (04/09) Vol. 15, P. 1836; Sun, L.; Su, X.H.; Guan, Y.S.
Fluorine MRI Tracks Immunotherapeutic Cell Types
Carnegie Mellon University researchers, led by Dr. B.M. Helfer, recently used a novel fluorine-based (F) MRI tracer agent to label clinically relevant human immune cells ex-vivo without a transfection reagent. This process allowed the tracer to be applied across both phagocytic and non phagocytic cell types without toxicity or altered proliferative characteristics. By doing so, researchers were able to visualize labeled cells by MRI in phantom studies as well as in-vivo after infection. Additionally, their study, presented at the American Association for Cancer Research Annual Meeting, found that pairing of the F MR image and conventional hydrogen (H) MRI, taken during the same MRI session, provided clear cell localization within anatomic context.
From "In Vivo Tracking of Immunotherapeutic Cell Types by Fluorine MRI"
American Association for Cancer Research (04/21/09) Helfer, B.M.; Nelson, A.D.; Janjic, J.M.
Simple IMRT Approach for the Treatment of Left-Sided Breast Cancer Reduces Risk of Cardiac Mortality
According to a recent study led by Universität Heidelberg Prof. Frank Lohr, aperture-based intensity-modulated radiotherapy (IMRT) significantly reduced the maximal dose to the left ventricle when used to treat left-sided breast cancer. Specifically, the study found that IMRT lowered the maximal dose to the left ventricle by a mean of 30.9 percent, while the mean dose to the left ventricle was reduced by an average of 10.7 percent and the mean heart dose increased by an average of 24 percent. A model-based reduction of the probability for excess therapy-associated cardiac death risk established that, in light of these findings, IMRT was able to reduce the cardiac death risk from 6.03 percent using a 3D treatment plan to 0.25 percent using IMRT plans.
From "Potential Effect of Robust and Simple IMRT Approach for Left-Sided Breast Cancer on Cardiac Mortality"
International Journal of Radiation Oncology, Biology, Physics (05/09) Vol. 74, No. 1, P. 73; Lohr, Frank; El-Haddad, Mostafa; Dobler, Barbara
Technology
Semiautomatic Volumetry Is Useful for Lung Nodule Management
Semiautomatic volumetry is sufficiently accurate and repeatable and may be useful in assisting with lung nodule management in a lung cancer screening program, according to a study published online in Radiology. The study, conducted by Dr. Alfonso Marchiano of the Fondazione IRCCS Instituto Nationale dei Tumori Department of Diagnostic Imaging in Milan and Radiotherapy and colleagues, created an automated software algorithm in pulmonary nodules detected during a lung cancer screening trial. Marchiano and his team tested the algorithm on 101 patients with 233 eligible nodules. The 95 percent confidence interval for difference in measured volumes was in the range of plus or minus 27 percent. Approximately 70 percent of measurements had a relative difference in nodule volume of less than 10 percent. There were no malignant lesions registered during follow-up for these subjects.
From "Pulmonary Nodules: Volume Repeatability at Multidetector CT Lung Cancer Screening"
Radiology Online (04/20/09) Marchiano, Alfonso; Calabro, Elisa; Civelli, Enrico
CBCT Provides Improved Treatment Planning
Dr. John D. Louie of the Stanford University Department of Radiology and colleagues established that cone-beam computed tomography (CBCT) can provide additional information about tumor and tissue perfusion not currently detectable using digital subtraction angiography (DSA) or technetium-99m-labeled macroaggregated (99m TcMAA) albumin scintigraphy. This conclusion is based on the findings of a study of 42 patients who underwent radioembolization and were evaluated using CBCT, DSA, and 99m TcMAA scintigraphy. The results showed that 52 percent of extrahepatic enhancement or incomplete tumor perfusion seen on CBCT affected the treatment plan, while in 33 percent of patients, the findings were found on CBCT but not DSA. When comparing CBCT and 99m TcMAA scintigraphy, CBCT showed 19 percent of extrahepatic enhancement not apparent on 99m TcMAA imaging.
From "Incorporating Cone-Beam CT Into the Treatment Planning for Yttrium-90 Radioembolization"
Journal of Vascular and Interventional Radiology (05/09) Vol. 20, No. 5, P. 606; Louie, John D.; Kothary, Nishita; Kuo, William T.
PET Imaging Has Limitations for Biological Adaptive-IMRT Assessed in Animal Models
Dose painting based on PET images should be carefully considered and should factor in possible discrepancies between PET images and the underlying microscopic reality represented by autoradiography (AR) images. These discrepancies were detected in a study conducted by Dr. Nicolas Christian of the Center for Molecular Imaging and Experimental Radiotherapy at the Universite Catholique de Louvain, in Brussels, and colleagues. In the study, which used a specific template for tumor-bearing mouse imaging, researchers segmented AR and FDG-PET images using a threshold-based method, selected to obtain absolute equal volumes in PET and AR images. Matching indexes were then calculated between the various volumes. This process allowed the researchers to establish low matching values of 39 percent between the volumes delineated on the PET images and those delineated on AR.
From "The Limitation of PET Imaging for Biological Adaptive-IMRT Assessed in Animal Models"
Radiotherapy & Oncology (04/09) Vol. 91, No. 1, P. 101; Christian, Nicolas; Lee, John A.; Bol, Anne
Medical-Legal Issues
New Rules Could Cut Physician Medicare Income
New Medicare rules could not only deny revenue for practices but even get them kicked out of the program. The new rules, which went into effect at the start of April, dramatically reduce the timeframe under which physicians can bill retroactively for services after a successful enrollment or re-enrollment from 27 months to 30 days. Practices must also alert contractors of any changes in practice locations within 30 days or risk being expelled from Medicare for up to two years. The changes were originally set to go into effect January 1 but were delayed after the American Medical Association and Medical Group Management Association successfully lobbied the Centers for Medicare & Medicaid Services (CMS) for a delay. CMS is telling physicians that it will not punish practices that are doing their best to comply and notes that there is a workaround for the enrollment problem that can extend the retroactive billing window.
From "New Rules Could Cut Physician Medicare Income"
Fierce Healthcare (04/20/2009)
Clinical Practice
Emergency Physicians Do Not Always use d-Dimer Screening Effectively to Evaluate the Need for CT in Patients With Suspected PE
D-Dimer screening currently is not used according to set diagnostic algorithms to determine the need for MDCT in patients with suspected acute pulmonary embolism (PE) in all emergency departments. This conclusion is based on a retrospective review of all patients who underwent d-dimer testing or MDCT in the emergency department of the Warren Albert Medical School of Brown University and Rhode Island Hospital. The review, led by Dr. Michael T. Corwin of the university's Department of Diagnostic Imaging, found that of 3,716 d-dimer tests, 39 percent were positive and 61 percent were negative. MDCT was performed in 7 percent of patients with negative d-dimer results and 58 percent of patients with positive results. The prevalence of PE in patients with a high clinical suspicion and no d-dimer testing was 9 percent, which was higher than the rate of PE in the positive d-dimer group at 2 percent. Furthermore, the researchers noted, there was no significant difference in the prevalence of PE in the positive and negative d-dimer groups.
From "Do Emergency Physicians Use Serum d-Dimer Effectively to Determine the Need for CT When Evaluating Patients for Pulmonary Embolism?"
American Journal of Roentgenology (05/01/2009) Vol. 192, No. 5, P. 1319; Corwin, Michael T.; Donohoo, Jay H.; Partridge, Robert
RSNA Weekly is a briefing of the latest radiology-related news selected from hundreds of sources by the editors of Information, Inc. While care is taken to use good sources, inaccuracies in source material are not the responsibility of RSNA or Information, Inc.
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