The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiation therapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the γ function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the lung and in the tumor area. These differences are not always in DVH of the lung, although the Wilcoxon test indicated significant differences in 2 of 4 patients. Disagreement in the lung region was also found when the Γ analysis was performed. The effect on TCP is less important than for NTCP because of the slope of the curve at the level of the dose of interest. The effect of dose calculation inaccuracy is patient-dependent and strongly related to beam geometry and to the localization of the tumor. When multiple intensity-modulated beams are used, the effect of the presence of the heterogeneity on dose distribution may not always be easily predictable.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.meddos.2010.03.008 | DOI Listing |
J Family Med Prim Care
November 2024
Centre for Community Medicine, All India Institute of Medical Sciences, New Delhi, India.
Introduction: Intravenous iron sucrose (IVIS) is a rapidly acting, safe, and effective treatment for moderate anemia among pregnant women. The effectiveness of IVIS at 6 months post IVIS infusion was unknown. We, therefore, assessed the mean increase in hemoglobin concentration and body iron replenishment status at 6 months after the last dose of IVIS infusion.
View Article and Find Full Text PDFFront Neurol
December 2024
Brain Rehabilitation Research Center, Malcom Randall Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, United States.
Background: High-dose testosterone replacement therapy (TRT), paired with finasteride (type II 5α-reductase inhibitor), improves body composition, muscle strength, and bone mineral density (BMD) in older men, without inducing prostate enlargement-a side effect associated with TRT. Men with spinal cord injury (SCI) exhibit neuromuscular impairment, muscle atrophy, bone loss, and increased central adiposity, along with low testosterone. However, sparse evidence supports TRT efficacy after SCI.
View Article and Find Full Text PDFLancet Digit Health
January 2025
Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Artificial Intelligence in Medicine (AIM) Program, Mass General Brigham, Harvard Medical School, Boston, MA, USA. Electronic address:
Background: Palliative spine radiation therapy is prone to treatment at the wrong anatomic level. We developed a fully automated deep learning-based spine-targeting quality assurance system (DL-SpiQA) for detecting treatment at the wrong anatomic level. DL-SpiQA was evaluated based on retrospective testing of spine radiation therapy treatments and prospective clinical deployment.
View Article and Find Full Text PDFParkinsonism Relat Disord
December 2024
Department of Neurosurgery, University of Iowa, Iowa City, IA, United States. Electronic address:
Introduction: Efficacy of deep brain stimulation (DBS) is established for several movement and psychiatric disorders. However, the mechanism of action and local tissue changes are incompletely described. We describe neurohistopathological findings of 9 patients who underwent DBS for parkinsonism and performed a systematic literature review on postmortem pathologic reports post-DBS.
View Article and Find Full Text PDFBMJ Open Respir Res
December 2024
Chiesi Ltd, Manchester, UK
Background: Inhalers are widely used for the management of asthma and chronic obstructive pulmonary disease. However, there is little knowledge about the extent to which an inhaler is used and when it is disposed of, despite the implications for an individual's health (when used beyond the recommended number of doses (overused)), and medicine wastage, healthcare costs and the environment (when discarded with remaining doses (underused)). To explore inhaler use, we assessed the number of doses remaining in pressurised metered-dose inhalers (pMDIs) returned via a Chiesi Inhaler Recycling scheme.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!