Browsing by Subject "Radiation Protection"

Now showing 1 - 4 of 4
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    ChatGPT versus Radiology Institutional Websites: Comparative Analysis of Radiation Protection Information Provided to Patients.
    (Radiology, 2024-06) Jankowski, Sofyan; Rotzinger, David; Ria, Francesco; Pozzessere, Chiara
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    Flattening filter-free accelerators: a report from the AAPM Therapy Emerging Technology Assessment Work Group.
    (Journal of applied clinical medical physics, 2015-05-08) Xiao, Ying; Kry, Stephen F; Popple, Richard; Yorke, Ellen; Papanikolaou, Niko; Stathakis, Sotirios; Xia, Ping; Huq, Saiful; Bayouth, John; Galvin, James; Yin, Fang-Fang
    This report describes the current state of flattening filter-free (FFF) radiotherapy beams implemented on conventional linear accelerators, and is aimed primarily at practicing medical physicists. The Therapy Emerging Technology Assessment Work Group of the American Association of Physicists in Medicine (AAPM) formed a writing group to assess FFF technology. The published literature on FFF technology was reviewed, along with technical specifications provided by vendors. Based on this information, supplemented by the clinical experience of the group members, consensus guidelines and recommendations for implementation of FFF technology were developed. Areas in need of further investigation were identified. Removing the flattening filter increases beam intensity, especially near the central axis. Increased intensity reduces treatment time, especially for high-dose stereotactic radiotherapy/radiosurgery (SRT/SRS). Furthermore, removing the flattening filter reduces out-of-field dose and improves beam modeling accuracy. FFF beams are advantageous for small field (e.g., SRS) treatments and are appropriate for intensity-modulated radiotherapy (IMRT). For conventional 3D radiotherapy of large targets, FFF beams may be disadvantageous compared to flattened beams because of the heterogeneity of FFF beam across the target (unless modulation is employed). For any application, the nonflat beam characteristics and substantially higher dose rates require consideration during the commissioning and quality assurance processes relative to flattened beams, and the appropriate clinical use of the technology needs to be identified. Consideration also needs to be given to these unique characteristics when undertaking facility planning. Several areas still warrant further research and development. Recommendations pertinent to FFF technology, including acceptance testing, commissioning, quality assurance, radiation safety, and facility planning, are presented. Examples of clinical applications are provided. Several of the areas in which future research and development are needed are also indicated.
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    Risk assessment and economic impact analysis of the implementation of new European legislation on radiopharmaceuticals in Italy: the case of the new monograph chapter Compounding of Radiopharmaceuticals (PHARMEUROPA, Vol. 23, No. 4, October 2011).
    (Curr Radiopharm, 2013-12) Chitto, Giuseppe; Di Domenico, Elvira; Gandolfo, Patrizia; Ria, Francesco; Tafuri, Chiara; Papa, Sergio
    An assessment of the new monograph chapter Compounding of Radiopharmaceuticals has been conducted on the basis of the first period of implementation of Italian legislation on Good Radiopharmaceuticals Practice (NBP) in the preparation of radiopharmaceuticals, in keeping with Decree by the Italian Ministry of Health dated March 30, 2005. This approach is well grounded in the several points of similarity between the two sets of regulations. The impact on patient risk, on staff risk, and on healthcare organization risk, has been assessed. At the same time, the actual costs of coming into compliance with regulations have been estimated. A change risk analysis has been performed through the identification of healthcare-associated risks, the analysis and measurement of the likelihood of occurrence and of the potential impact in terms of patient harm and staff harm, and the determination of the healthcare organization's controlling capability. In order to evaluate the economic impact, the expenses directly related to the implementation of the activities as per ministerial decree have been estimated after calculating the overall costs unrelated to NBP implementation. The resulting costs have then been averaged over the total number of patient services delivered. NBP implementation shows an extremely positive impact on risk management for both patients receiving Nuclear Medicine services and the healthcare organization. With regard to healthcare workers, instead, the implementation of these regulations has a negative effect on the risk for greater exposure and a positive effect on the defense against litigation. The economic impact analysis of NBP implementation shows a 34% increase in the costs for a single patient service. The implementation of the ministerial decree allows for greater detectability of and control over a number of critical elements, paving the way for risk management and minimization. We, therefore, believe that the proposed tool can provide basic criteria for analysis that could be used by other organizations setting about completing the same process.
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    Spectrotemporal CT data acquisition and reconstruction at low dose.
    (Med Phys, 2015-11) Clark, Darin P; Lee, Chang-Lung; Kirsch, David G; Badea, Cristian T
    PURPOSE: X-ray computed tomography (CT) is widely used, both clinically and preclinically, for fast, high-resolution anatomic imaging; however, compelling opportunities exist to expand its use in functional imaging applications. For instance, spectral information combined with nanoparticle contrast agents enables quantification of tissue perfusion levels, while temporal information details cardiac and respiratory dynamics. The authors propose and demonstrate a projection acquisition and reconstruction strategy for 5D CT (3D+dual energy+time) which recovers spectral and temporal information without substantially increasing radiation dose or sampling time relative to anatomic imaging protocols. METHODS: The authors approach the 5D reconstruction problem within the framework of low-rank and sparse matrix decomposition. Unlike previous work on rank-sparsity constrained CT reconstruction, the authors establish an explicit rank-sparse signal model to describe the spectral and temporal dimensions. The spectral dimension is represented as a well-sampled time and energy averaged image plus regularly undersampled principal components describing the spectral contrast. The temporal dimension is represented as the same time and energy averaged reconstruction plus contiguous, spatially sparse, and irregularly sampled temporal contrast images. Using a nonlinear, image domain filtration approach, the authors refer to as rank-sparse kernel regression, the authors transfer image structure from the well-sampled time and energy averaged reconstruction to the spectral and temporal contrast images. This regularization strategy strictly constrains the reconstruction problem while approximately separating the temporal and spectral dimensions. Separability results in a highly compressed representation for the 5D data in which projections are shared between the temporal and spectral reconstruction subproblems, enabling substantial undersampling. The authors solved the 5D reconstruction problem using the split Bregman method and GPU-based implementations of backprojection, reprojection, and kernel regression. Using a preclinical mouse model, the authors apply the proposed algorithm to study myocardial injury following radiation treatment of breast cancer. RESULTS: Quantitative 5D simulations are performed using the MOBY mouse phantom. Twenty data sets (ten cardiac phases, two energies) are reconstructed with 88 μm, isotropic voxels from 450 total projections acquired over a single 360° rotation. In vivo 5D myocardial injury data sets acquired in two mice injected with gold and iodine nanoparticles are also reconstructed with 20 data sets per mouse using the same acquisition parameters (dose: ∼60 mGy). For both the simulations and the in vivo data, the reconstruction quality is sufficient to perform material decomposition into gold and iodine maps to localize the extent of myocardial injury (gold accumulation) and to measure cardiac functional metrics (vascular iodine). Their 5D CT imaging protocol represents a 95% reduction in radiation dose per cardiac phase and energy and a 40-fold decrease in projection sampling time relative to their standard imaging protocol. CONCLUSIONS: Their 5D CT data acquisition and reconstruction protocol efficiently exploits the rank-sparse nature of spectral and temporal CT data to provide high-fidelity reconstruction results without increased radiation dose or sampling time.