![]() Nuclear explosions can cause significant damage and casualties from blast, heat, and radiation but you can keep your family safe by knowing what to do and being prepared if it occurs.Ī nuclear weapon is a device that uses a nuclear reaction to create an explosion. Leaders in Business Community Resilience.They show the potential of synchrotron radiation for absolute high-resolution morphological and functional CT imaging, and for new therapeutic modalities using intense monochromatic x rays. The two complementary methods developed in this thesis offer perspectives in the understanding of the glioma growth process and in their treatment by radiation therapy. Significant survival increases were obtained, especially when the delivery of iodine is coupled with a transient blood-brain-barrier opener. The methodology, the associated dosimetry as well as the preclinical validation of iodine enhanced strereotactic synchrotron radiation therapy is developed in the thesis. The beam properties allow the selection of monochromatic irradiation, at the optimal energy, for a maximal dose deposit in the tumor, while sparing healthy tissues. Synchrotron beams, providing high intensity, tunable monochromatic x rays, are ideal for this treatment. The dose enhancement results from the photoelectric effect on the heavy element and from the irradiation geometry. The contrast agent accumulates in the tumor, through the broken blood brain barrier, and the irradiation is performed with kilovoltage x rays, in tomography mode, the tumor being located at the center of rotation and the beam size adjusted to the tumor dimensions. One strategy to overcome this limitation is to infuse an iodinated contrast agent to the patient during the irradiation. In conventional radiotherapy, the treatment of these tumors remains a delicate challenge, because the damages to the surrounding normal brain tissue limit the amount of radiation that can be delivered. There is a great opportunity, but also more » many technical challenges, for the accelerator community to create the required dose rates with novel and compact accelerators to ensure the safe delivery of FLASH radiation beams. Still, it is currently estimated that large doses of 10 Gy or more delivered in 200 ms or less produce normal tissue sparing effects yet effectively kill tumor cells. The dose delivery conditions are not yet fully characterized. Experimental studies have shown that normal tissues seem to be universally spared at these high dose rates, whereas tumors are not. FLASH radiation therapy (FLASH-RT) is an ultra-high dose-rate delivery of a therapeutic radiation dose within a fraction of a second. Recently, however, a fundamentally different paradigm for increasing the therapeutic index of radiation therapy has emerged, supported by preclinical research, and based on the FLASH radiation effect. However, treatment and cure are still limited by normal tissue radiation toxicity, with many patients experiencing acute and long-term side effects. The general concept of radiation therapy is to increase the therapeutic index by creating a physical dose differential between tumors and normal tissues through precision dose targeting, image guidance, and high radiation beams that deliver radiation dose with high conformality, e.g., protons and ions. These modalities are often combined to improve the therapeutic index. ![]() Conventional cancer therapies include surgery, radiation therapy, chemotherapy, and, more recently, immunotherapy.
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