Radiation Treatments

Radiation treatment Radiation window Radiative lifetimes Radiative recombination... 

Laboratory tests indicated that gamma radiation treatment and cross-linking using triaHylcyanurate or acetylene produced a flexible recycled plastic from mixtures of polyethylene, polypropylene, general-purpose polystyrene, and high impact grade PS (62). 

Alkali AletalIodides. Potassium iodide [7681-11-0] KI, mol wt 166.02, mp 686°C, 76.45% I, forms colorless cubic crystals, which are soluble in water, ethanol, methanol, and acetone. KI is used in animal feeds, catalysts, photographic chemicals, for sanitation, and for radiation treatment of radiation poisoning resulting from nuclear accidents. Potassium iodide is prepared by reaction of potassium hydroxide and iodine, from HI and KHCO, or by electrolytic processes (107,108). The product is purified by crystallization from water (see also Feeds and feed additives Photography). 

To avoid homopolymer formation, it is necessary to ensure true molecular contact between the monomer and the polymer. Even if this is initially established, it needs to be maintained during the radiation treatment while the monomer is undergoing conversion. Several methods are used for minimizing the homopolymer formation. These include the addition of metal cations, such as Cu(II) and Fe(II). However, by this metal ion technique, both grafting and homopolymerization are suppressed to a great extent, thus permitting reasonable yield of graft with little homopolymer contamination by the proper selection of the optimum concentration of the inhibitor [83,90,91]. 

Nicotinamide potentiates the cytotoxic effects of chemotherapy and radiation treatment against tumor cells. This effect is probably attributable to increased... 

A neutron can get close to a target nucleus more easily than a proton can. Because a neutron has no charge and hence is not repelled by the nuclear charge, it need not be accelerated to such high speeds. An example of neutron-induced transmutation is the formation of cobalt-60, which is used in the radiation treatment of cancer. The three-step process starts from iron-58. First, iron-59 is produced ... 

Romero-Sanchez M.D., Pastor-Bias M.M., Martm-Martmez J.M., Zhdan P.A., and Watts J.M., 2001, Surface modifications in a vulcanized rubber using corona discharge and ultraviolet radiation treatments, J. Materials Sci., 36(24), 5789-5799. 

Radiation Treatment NVP, 2-hydroxyethylmethacrylate (HEMA), and acrylamide (AAm) have been grafted to the surface of ethylene-propylene-diene monomer (EPDM) rubber vulcanizates using the radiation method (from a Co 7 source) to alter surface properties such as wettability and therefore biocompatibility [197]. Poncin-Epaillard et al. [198] have reported the modification of isotactic PP surface by EB and grafting of AA onto the activated polymer. Radiation-induced grafting of acrylamide onto PE is very important... 

Co, used in radiation treatments of cancer (b) thallium-201, used for diagnosis of coronary artery... 

The resistance of an organism to a sterilizing agent can be described by means of the D-value. For heat and radiation treatments, respectively, this is defined as the time taken at a fixed temperature or the radiation dose required to achieve a 90% reduction in viable cells (i.e. a 1 log cycle reduction in survivors Fig. 20.2k). The calculation of the D-value assumes a linear type A survivor curve (Fig. 20.1), and must be corrected to allow for any deviation from linearity with type B or C curves. Some typical D-values for resistant bacterial spores are given in Table 23.2 (Chapter 23). 

Potential disadvantages and effectiveness of surgery and radiation treatment... 

Prior radiation treatment to the breast or chest wall... 

Risk factors for the development of AML include exposure to environmental toxins, Hispanic ethnicity, and genetics.6 Of greater concern is the increased prevalence of AML as a secondary malignancy, resulting from chemotherapy and radiation treatment for other cancers. Alkylating agents, such as ifosfamide and cyclophosphamide, and topoisomerase inhibitors, such as etoposide, are linked to an increased risk of myelodysplastic syndrome (MDS) and AML.8... 

Considerable research has been done in many industrial countries, especially in Japan and in the former U.S.S.R., on the radiation treatment of waste water and other liquid wastes (see Pikaev and Shubin, 1984 Sakumoto and Miyata, 1984). Apart from disinfection or sterilization, the processes involve the radiation treatment of polluted water, the radiation-induced decomposition of dyes, phenols, cyanides, and so forth, (vide supra). At the basis of purification of aqueous waste... 

Heron, D. E., Andrade, R. S., Flickinger, J. et al. Hybrid PET-CT simulation for radiation treatment planning in head-and-neck cancers a brief technical report. Int. J. Radiation Oncology Biol. Phys., 60 1419-1424,2004. 

The work of Ito and coworkers65 (Japan) on fibrosarcoma in mice showed that ECT retarded the tumor growth in mice the best results were obtained when ECT was preceded by a radiation treatment. 

CEO, Stephen Hoffman and VP for clinical studies, Michael Gerber of Alios Therapeutics guided RSR 13 through a series of phase-one and phase-two clinical trials for radiation treatment of brain tumors and for potential use in cardiopulmonary bypass surgery [46, 51-55]. Considering the cost of running a phase-three clinical trial, only one was possible. The very positive phase-two results for use of RSR 13 to treat metastatic brain cancer provided the impetus for selecting that indication for a phase-three trial. 

It is my opinion that if RSR 13 is approved, its potential use in medicine could be far beyond the radiation treatment of tumors. RSR 13 is the first molecule with... 

Radiation treatment schemes that accelerate the dose delivery, i.e., attempt to deliver it in a shorter overall time, endeavor to compensate for any accelerated repopulation of the tumor that may be occurring. These schemes are often accompanied by increased morbidity. Ultimately abetter understanding of the molecular and cellular events involved may give rise to measures that will allow us to compensate for accelerated repopulation in tumors or to induce repopulation in normal tissues earlier in a course of therapy in order to minimize treatment related morbidity. 

Keeping the above principles in mind, Herscher et al. gives an excellent overview of the characteristics of an idealized radiation modifier (35). In the case of the radiation protector more dose can be delivered to the tumor and in the case of a sensitizer more effective dose can be delivered. In theory the ideal radiation enhancer will have selective systemic activity against malignant but not against nonmalignant cells, will reach the tumor in adequate concentrations to affect radiation, and will have been studied such that the ideal timing with relation to radiation treatment delivery will be defined. Such a compound will increase the effects of radiation in one of several ways (see Fig. 2) ... 

Cyclicity of administration is vital in the use of 5-FU as a radiosensitizer. The concept of cyclical treatment has been well established in cancer chemotherapy and alien to classical radiation therapy (where it is termed split-course therapy). 5-FU radio-sensitizes tumor tissue as well as normal cells. However, this normal tissue radio-sensitizationis limited to the irradiated field. Suitable fractionation (i.e., cyclical therapy) can permit rapid normal tissue recovery (23). The results of infused 5-FU and radiation in head and neck cancer supports the principle that cyclical treatment with 5-FU does not suffer from the limitations apparent in split-course radiation treatments. 

These studies were followed by others that demonstrated the potential for therapeutic enhancement by combined cisplatin-radiation treatments with primary murine bladder cancer (60), EMT-6 mammary tumors and KHT and RIF-1 sarcomas (61), and Lewis lung carcinoma (62). 

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