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Enrique Gaona
Universidad Autonoma Metropolitana - Xochimilco
Mexico City, Mexico
"Reflexiones en el desarrollo de la dosimetría y
la física médica en México: Una perspectiva histórica" |
Some historical reflections are presented that highlight events, names of pioneers
and institutions that have contributed to the development of dosimetry and medical physics in Mexico.
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Telma Cristina Ferreira Fonseca
Escola do Engenharia, Universidade Federal de Minas Gerais
Belo Horizonte, Brazil
"In Silico and in vitro approaches: A way to understanding Radiation therapy in nanoscale" |
Radiotherapy has been a cornerstone in cancer treatment for decades, yet the intricate mechanisms at the nanoscale level remain partially understood. Recent advancements in in silico and in vitro methodologies have provided significant insights into these mechanisms, offering a deeper comprehension of the interactions between ionizing radiation and biological tissues at the molecular level. This review highlights the synergistic use of computational models and experimental approaches to explore the effects of radiation on DNA, proteins, and other critical biomolecules. In silico models, particularly Monte Carlo simulations, allow for precise predictions of radiation interactions, while in vitro studies validate these predictions and reveal the complex biological responses. Together, these approaches facilitate a better understanding of dose distribution, DNA damage, and repair mechanisms, ultimately contributing to the optimization of radiotherapy protocols. By integrating these methods, researchers can uncover the underlying processes that dictate the efficacy and side effects of radiotherapy, paving the way for more targeted and effective treatments,
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Virgilio Correcher
Environment Department, Radiation Dosimetry, CIEMAT
Madrid, Spain
"New data on the use of dental crowns as individual luminescence dosimeters" |
Luminescence properties of dental crowns makes these materials of interest in the field of individual retrospective dosimetry. This characteristic may serve as a valuable tool for assessing cumulative exposure to external gamma radiation in scenarios involving large-scale incidents, such as accidents or radiological terrorism, particularly in population groups where conventional dosimetry has not been implemented. The thermal stability and dose response of the UV-blue thermoluminescence (TL) emission of well-characterized Spanish samples, analyzed using environmental scanning electron microscopy and electron probe microanalysis, are presented. The TL and optically stimulated luminescence (OSL) emissions exhibit (i) a linear dose response when exposed to ionizing radiation in the range of 0.1 to 10 Gy; (ii) high stability of the TL signal in irradiated samples after 6 months of storage, showing an initial rapid decay of approximately 30%, followed by stability from 30 days onwards; (iii) reusability tests on dental ceramics, involving successive cycles of irradiation + TL readout, revealed no variation in the TL response after seven cycles; and (iv) an assessment of the effect of exposure to natural light, which induced phototransferred thermoluminescence (PTTL) processes. These preliminary results indicate that dental ceramics could serve as effective dosimeters in retrospective dosimetry scenarios.
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Jose Eduardo Villarreal-Barajas
Head of Radiotherapy Physics, Royal Devon University and Torbay Hospitals
Exeter, United Kingdom
"Photoluminescence of pure LiF for medical dosimetry applications;
Are we there yet? " |
The use of LiF as a thermoluminescent dosimetric (TLD) material has been well established for over 50 years. Perhaps the most widely used and know TL material is LiF:Mg,Ti commercially known as TLD-100, patented by Harshaw Chemical Company in 1963 [1]. LiF with different dopants is used for a wide range of dosimetric applications and for a variety of ionizing radiation sources, from heavy ions to low energy X-rays. From the early 2000’s, Al2O3:C has been successfully used as a versatile Optically Stimulated Luminescence (OSL) dosemeter for medical dosimetry applications [2]. The fast OSL reading-evaluation of Al2O3:C, good stability and multiple reading with minimal signal loss and 2D dose mapping capabilities, made OSL-Al2O3::C the preferred choice for clinical dosimetry applications. More recently, it has been proposed the use of nominally pure LiF crystals as a photoluminescence (PL) dosimeter for clinical dosimetry [3]. This presentation will discuss the latest developments and investigations on the use of LiF as a PL-based clinical dosemeter.
[1] McKeever S W et. al. (1995), Thermoluminescence Dosimetry Materials, NTP.
[2] Akselrod et al. (2007), Radiat. Meas., 41, S78.
[3] Villarreal-Barajas et al. (2015), 12Th EURODIM, IOP Conf. Series Mat. Sci. Eng. 80.
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Wesley E. Bolch
Herbert Wertheim College of Engineering, University of Florida
USA
"Highlights on the new UNSCEAR report on second primary Cancer risking following radiotherapy" |
The United Nations Scientific Committee of the Effects of Atomic Radiation (UNSCEAR) was established by the Unite Nations General Assembly resolution 913(X) on December 3, 1955. The Committee’s mandate has been to undertake broad scientific reviews of the sources levels and resulting effects of ionizing radiation on human health and the environmental. In 2018, the Committee established an Expert Group to undertaken a review of second primary cancers (SPCs) following radiotherapy. Ionizing radiation is one of many techniques in the treatment and potential eradication of cancer, with approximately 50% of all cancer patients receiving some form of radiotherapy. Most importantly, it is estimated that radiation contributes roughly 40% to the overall curative treatment of cancer. As with nearly all forms of therapeutic medicine, there are adverse effects of treatment. For radiotherapy, these fall within two broad categories – normal organ toxicities (radiation tissue reactions) and the induction of a second primary cancer (stochastic radiation effect). During the radiotherapy treatment planning process using externally delivered radiation beams, only the former adverse effect is currently explicitly included in the optimization of the beam energies, intensities, and entrance directions to the patient’s body. There are four broad objectives of the Committee’s reivew of SPCs following radiotherapy. These are (1) to evaluate the risks of second primary cancers following radiotherapy through a detailed review of published radiation epidemiological studies from which a meta-analysis of risk is performed; (2) to evaluate the contribution of ionizing radiation independently from the contribution of chemotherapy and their combined effects; (3) to promote a rigorous dosimetric framework for the assignment and/or reconstruction of organ doses in patients that can contribute usefully to both retrospective as well as prospective epidemiological studies; and (4) to address future research needs to both assemble suitable patient cohorts for future risk studies, and to explore how genetics and radiotherapy interact, as well as the link between radiotherapy and other cancer-causing agents. This presentation will summarize the current status of this review.
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Izabella Barreto
Clinical Radiological Physics, University of Florida
USA
"Optimizing radiation dose in CT Imaging for adult and pediatric patients: Strategies for effective management" |
Optimizing radiation dose in CT imaging is critical for balancing diagnostic image quality with patient safety, particularly for vulnerable populations such as pediatric patients. This session explores strategies for effective dose management in both adult and pediatric CT imaging, emphasizing the implementation of individualized dose protocols and the integration of state-of-the-art technologies. Techniques such as automated tube current modulation, iterative reconstruction algorithms, and dual-energy CT are examined for their potential to reduce radiation exposure while maintaining diagnostic efficacy. Additionally, pediatric-specific considerations are addressed, including age and size-based protocol adjustments and the application of radiation dose tracking and reporting systems. By synthesizing current research and clinical guidelines, this session provides a comprehensive overview of best practices for minimizing radiation dose in CT imaging, ultimately contributing to enhanced patient care and safety in radiological practices.
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