Showing papers by "Michael T. McDermott published in 2011"

New American Thyroid Association and American Association of Clinical Endocrinologists Guidelines for Thyrotoxicosis and Other Forms of Hyperthyroidism: Significant Progress for the Clinician and a Guide to Future Research

Abstract: The authors of the new American Thyroid Association (ATA) and American Association of Clinical Endocrinologists (AACE) guidelines for hyperthyroidism and other forms of thyrotoxicosis, published in this issue (1), are to be congratulated. These guidelines are much needed. They serve to update separate previous guidelines from the ATA in 1995 (2) and from AACE in 2002 (3). The updated version is far more comprehensive than the older versions, including topics such as thyroiditis, gestational thyrotoxicosis, surgical preparation and extent, and radiation safety, which were not previously discussed. The new guidelines are also more modern in format, incorporating separate recommendations together with levels of evidence. An important shortcoming of the new guidelines is that they are based on relatively limited available evidence. Of the 100 graded recommendations, 80 are strong recommendations (grade 1) and 20 are weak recommendations (grade 2). Seventy are based on low-quality evidence (þ), 29 are based on moderate-quality evidence (þþ), and only one is based on high-quality evidence (þþþ). Of the 80 strong recommendations, 56 (70%) are based on low-quality evidence (þ), 23 (29%) are based on moderate-quality evidence (þþ), and only one (1%) is based on high-quality evidence (þþþ). Of the 20 weak recommendations, 15 (75%) are based on low-quality evidence (þ) and five (25%) are based on moderate-quality evidence (þþ). Therefore, most are strong recommendations that are based on low-quality evidence. This indicates that clinical management of hyperthyroidism is still largely rooted in expert opinion and personal experience. Given this, it is perhaps remarkable that 98 of the recommendations were unanimous, whereas two of the recommendations had a single dissenting member. One goal of this editorial is to explore areas where we three editorialists disagreed with the recommendations and with each other. One minor area of disagreement among us relates to determining the etiology of thyrotoxicosis. All of us appreciate the guidelines’ emphasis on the use of the radioactive iodine uptake when the etiology of hyperthyroidism is not clinically apparent. However, one of us feels that, given concerns about unnecessary medical radiation exposure and costs, thyroid receptor antibody (TRAb) testing should be considered as an alternative to nuclear medicine testing in all patients, not just pregnant and nursing women. All of us are united in the hope that these guidelines will help to decrease the ordering of unnecessary iodinated contrast imaging in hyperthyroid patients, an all-too-frequent practice that delays subsequent radioactive iodine imaging or treatment. With regard to ruling out factitious thyrotoxicosis, we would add that the triiodothyronine (T3)/thyroxine (T4) ratio is typically <20 with excess L-thyroxine (LT4) ingestion and >20 with excess T3 ingestion, but it may be unhelpful in thyroid hormone extract ingestion because the T4/T3 ratios of thyroid hormone extract products may be inconsistent. Although the U.S. Food and Drug Administration has warned against this practice, manufacturers have previously marketed 3,5,30-triiodothyroacetic acid (TRIAC)-containing supplements as weight loss aids. High TRIAC doses would be expected to cause low serum thyrotopin (TSH) and T4 levels, but elevated serum T3 due to cross-reactivity of TRIAC with T3 assays (4). The suggestion to check fecal T4 levels to rule out factitious thyrotoxicosis in thyroglobulin antibody positive patients is both novel and helpful. The previous AACE guidelines noted that ‘‘in the U.S. radioactive iodine is currently the treatment of choice for Graves’’’ and largely ignored other treatment options. The new guidelines give more equal and balanced consideration to I-131, anti-thyroid drugs (ATDs), and surgery in the management of Graves’ disease. We applaud Recommendation 4, with its emphasis on individualizing the management plan with proper attention paid to the preferences of each patient. Although all therapeutic options are recognized, we believe that the duration of ATD use is appropriately limited under the current guidelines. Definitive therapy is preferred in

Use of proton magnetic resonance spectroscopic imaging data in planning focal radiation therapies for brain tumors

Abstract: Advances in radiation therapy for malignant neoplasms have produced techniques such as Gamma Knife radiosurgery, capable of delivering an ablative dose to a specific, irregular volume of tissue. However, efficient use of these techniques requires the identification of a target volume that will produce the best therapeutic response while sparing surrounding normal brain tissue. Accomplishing this task using conventional computed tomography (CT) and contrast-enhanced magnetic resonance imaging (MRI) techniques has proven difficult because of the difficulties in identifying the effective tumor margin. Magnetic resonance spectroscopic imaging (MRSI) has been shown to offer a clinically-feasible metabolic assessment of the presence and extent of neoplasm that can complement conventional anatomic imaging. This paper reviews current Gamma Knife protocols and MRSI acquisition, reconstruction, and interpretation techniques, and discusses the motivation for including magnetic resonance spectroscopy findings while planning focal radiation therapies. A treatment selection and planning strategy incorporating MRSI is then proposed, which can be used in the future to assess the efficacy of spectroscopy-based therapy planning.

Comprar Al-Mefty's Meningiomas | Michael McDermott | 9781604060539 | Thieme

Abstract: Tienda online donde Comprar Al-Mefty's Meningiomas al precio 179,50 € de Michael McDermott | Franco DeMonte | Ossama Al-Mefty, tienda de Libros de Medicina, Libros de Medicina Interna - Medicina interna