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Start Over Author "Arthur, J. A." Publisher elsevier b.v.
1,694 results on '"Arthur, J. A."'

39. Physics Considerations for Evaluation of Dose for Dose-Response Models of Pediatric Late Effects From Radiation Therapy: A PENTEC Introductory Review.

Author

Olch, Arthur J., van Luijk, Peter, Hua, Chia-Ho, Avanzo, Michele, Howell, Rebecca M., Yorke, Ellen, Aznar, Marianne C., and Kry, Stephen F.

Subjects
*RADIOTHERAPY, *DRUG dosage, *CHILD patients, *TASK forces, *LITERARY sources
Abstract

We describe the methods used to estimate the accuracy of dosimetric data found in literature sources used to construct the Pediatric Normal Tissue Effects in the Clinic (PENTEC) dose-response models, summarize these findings of each organ-specific task force, describe some of the dosimetric challenges and the extent to which these efforts affected the final modeling results, and provide guidance on the interpretation of the dose-response results given the various dosimetric uncertainties. Each of the PENTEC task force medical physicists reviewed all the journal articles used for dose-response modeling to identify, categorize, and quantify dosimetric uncertainties. These uncertainties fell into 6 broad categories. A uniform nomenclature was developed for describing the "dosimetric quality" of the articles used in the PENTEC reviews. Among the multidisciplinary experts in the PENTEC effort, the medical physicists were charged with the dosimetric evaluation, as they are most expert in this subject. The percentage dosimetric uncertainty was estimated for each late effect endpoint for all PENTEC organ reports. Twelve specific sources of dose uncertainty were identified related to the 6 broad categories. The most common reason for organ dose uncertainty was that prescribed dose rather than organ dose was reported. Percentage dose uncertainties ranged from 5% to 200%. Systematic uncertainties were used to correct the dose component of the models. Random uncertainties were also described in each report and in some cases used to modify dose axis error bars. In addition, the potential effects of dose binning were described. PENTEC reports are designed to provide guidance to radiation oncologists and treatment planners for organ dose constraints. It is critical that these dose constraint recommendations are as accurate as possible, acknowledging the large error bars for many. Achieving this accuracy is important as it enables clinicians to better balance target dose coverage with risk of late effects. Evidence-based dose constraints for pediatric patients have been lacking and, in this regard, PENTEC fills an important unmet need. One must be aware of the limitations of our recommendations, and that for some organ systems, large uncertainties exist in the dose-response model because of clinical endpoint uncertainty, dosimetric uncertainty, or both. [ABSTRACT FROM AUTHOR]

Published
2024
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40. Pediatric Normal Tissue Effects in the Clinic (PENTEC): An International Collaboration to Assess Normal Tissue Radiation Dose-Volume-Response Relationships for Children With Cancer.

Author

Constine, Louis S., Olch, Arthur J., Jackson, Andrew, Hua, Chia-Ho, Ronckers, Cecile M., Milano, Michael T., Marcus, Karen J., Yorke, Ellen, Hodgson, David C., Howell, Rebecca M., Hudson, Melissa M., Williams, Jacqueline P., Marples, Brian, C.M. Kremer, Leontien, Marks, Lawrence B., and Bentzen, Søren M.

Subjects
*CHILDHOOD cancer, *TISSUES, *RADIATION
Published
2024
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49. Reliability of isokinetic decay slope is superior to using fatigue indices for shoulder horizontal abduction.

Author

Evans, Neil A., Simon, Janet E., Konz, Suzanne M., Nitz, Arthur J., and Uhl, Timothy L.

Abstract

Reliable and valid measurements for shoulder muscular endurance should be available for clinical use. The posterior shoulder endurance test offers a potential clinical assessment, but its construct validity isn't available. Since a criterion measure of muscular endurance is not available, this study's purpose was to determine a reliable method for testing shoulder muscular endurance using an isokinetic dynamometer. The test-retest reliability, standard error measurement, and minimal detectable change were calculated on four different paradigms to quantify muscular fatigue using two isokinetic speeds (60°sec−1,180°sec−1). Calculation paradigms included peak torque fatigue index (FI), average torque FI, area-under-the-curve FI, and peak torque decay slope. Testing occurred on two days. Repeated measures analysis of variance compared the two peak torque decay slopes across both testing days. Superior reliability was found within the decay slope measurements at both 60°sec−1 (ICC = 0.941) and 180°sec−1 (ICC = 0.764) speeds, with the 60°sec−1 decay slope being the highest reliability between the two angular velocities. There was a greater amount of fatigue in the 60°sec−1 decay slope compared to the 180°sec−1 decay slope. Using the decay slope of isokinetic shoulder horizontal abduction at 60°sec−1 is a reliable method to validate other muscular endurance clinical measures. Rehabilitation specialists should utilize the decay slope of the isokinetic dynamometry to monitor responsiveness. [ABSTRACT FROM AUTHOR]

Published
2024
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