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Nuclear medicine uses radiopharmaceuticals for disease treatment and as tracers in medical imaging studies. Yttrium-90 (⁹⁰Y) is a radiopharmaceutical agent used to treat overgrown joint lining known as pigmented villonodular synovitis, as well as some forms of liver cancer. It has a half-life of about 64 hours.Although the relatively short half-life of ⁹⁰Y is optimal for use in medical applications, transportation and storage of the radiopharmaceutical are not feasible. As a result, strontium-90 (⁹⁰Sr) , with a half-life of 28.8 years, is the most common source of ⁹⁰Y. ⁹⁰Sr is created by a nuclear fission process that begins with uranium-235 (²³⁵U) in a nuclear reactor as shown in Reaction 1.²³⁵U → ⁹⁰Sr + ZReaction 1Fission of ²³⁵U produces ⁹⁰Sr as well as additional fission products (Z) including, but not limited to, technetium-99 (⁹⁹Tc) , iodine-129 (¹²⁹I) , and zirconium-93 (⁹³Zr) . Figure 1 shows the distribution of fission products.
Figure 1 Distribution of ²³⁵U fission products by atomic weightTo create the final ⁹⁰Y required for nuclear medicine studies, ⁹⁰Sr decay is carried out in a controlled ⁹⁰Y generator. ⁹⁰Y is then separated from residual ⁹⁰Sr for use in clinical applications.
Adapted from Wheeler CE. Comments on vaccines, August 1987. J Am Acad Dermatol. 1988;18(1 Pt 2) :232-4.
-Strontium is converted to yttrium by which of the following processes?

Question

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Nuclear medicine uses radiopharmaceuticals for disease treatment and as tracers in medical imaging studies. Yttrium-90 (⁹⁰Y) is a radiopharmaceutical agent used to treat overgrown joint lining known as pigmented villonodular synovitis, as well as some forms of liver cancer. It has a half-life of about 64 hours.Although the relatively short half-life of ⁹⁰Y is optimal for use in medical applications, transportation and storage of the radiopharmaceutical are not feasible. As a result, strontium-90 (⁹⁰Sr) , with a half-life of 28.8 years, is the most common source of ⁹⁰Y. ⁹⁰Sr is created by a nuclear fission process that begins with uranium-235 (²³⁵U) in a nuclear reactor as shown in Reaction 1.²³⁵U → ⁹⁰Sr + ZReaction 1Fission of ²³⁵U produces ⁹⁰Sr as well as additional fission products (Z) including, but not limited to, technetium-99 (⁹⁹Tc) , iodine-129 (¹²⁹I) , and zirconium-93 (⁹³Zr) . Figure 1 shows the distribution of fission products.

Passage Nuclear medicine uses radiopharmaceuticals for disease treatment and as tracers in medical imaging studies. Yttrium-90 (<sup>90</sup>Y) is a radiopharmaceutical agent used to treat overgrown joint lining known as pigmented villonodular synovitis, as well as some forms of liver cancer. It has a half-life of about 64 hours.Although the relatively short half-life of <sup>90</sup>Y is optimal for use in medical applications, transportation and storage of the radiopharmaceutical are not feasible. As a result, strontium-90 (<sup>90</sup>Sr) , with a half-life of 28.8 years, is the most common source of <sup>90</sup>Y. <sup>90</sup>Sr is created by a nuclear fission process that begins with uranium-235 (<sup>235</sup>U) in a nuclear reactor as shown in Reaction 1.<sup>235</sup>U → <sup>90</sup>Sr + Z<strong>Reaction 1</strong>Fission of <sup>235</sup>U produces <sup>90</sup>Sr as well as additional fission products (Z) including, but not limited to, technetium-99 (<sup>99</sup>Tc) , iodine-129 (<sup>129</sup>I) , and zirconium-93 (<sup>93</sup>Zr) . Figure 1 shows the distribution of fission products. <strong>Figure 1</strong> Distribution of <sup>235</sup>U fission products by atomic weightTo create the final <sup>90</sup>Y required for nuclear medicine studies, <sup>90</sup>Sr decay is carried out in a controlled <sup>90</sup>Y generator. <sup>90</sup>Y is then separated from residual <sup>90</sup>Sr for use in clinical applications. Adapted from Wheeler CE. Comments on vaccines, August 1987. J Am Acad Dermatol. 1988;18(1 Pt 2) :232-4. -Strontium is converted to yttrium by which of the following processes? A) Electron capture B) Positron emission C) Gamma ray emission D) Beta emission

Figure 1 Distribution of ²³⁵U fission products by atomic weightTo create the final ⁹⁰Y required for nuclear medicine studies, ⁹⁰Sr decay is carried out in a controlled ⁹⁰Y generator. ⁹⁰Y is then separated from residual ⁹⁰Sr for use in clinical applications.
Adapted from Wheeler CE. Comments on vaccines, August 1987. J Am Acad Dermatol. 1988;18(1 Pt 2) :232-4.
-Strontium is converted to yttrium by which of the following processes?

Quizplus · Accepted Answer

11ecba2d_1189_54a6_a3bf_053adaceb0b1_MD0008_00 The mass of an atom is centered in the nucleus, where each proton and neutron has an atomic mass of approximately 1. Because protons and neutrons have approximately the same mass, changing one to the other does not significantly alter the mass of the atom. However, such a change alters the identity of the element, which is determined only by the number of protons in the nucleus. Protons and neutrons can be interconverted by the following mechanisms: Beta emission is the ejection of an electron or a positron from the nucleus. The most common form of beta decay is emission of a nuclear electron, which results from a neutron decaying into a proton and increases the atomic number by one. Positron emission converts a proton into a neutron, decreasing the atomic number by one. Electron capture is the process by which a nucleus absorbs an electron from an external source. The added negative charge converts a proton into a neutron, decreasing the atomic number by one. The periodic table shows that strontium has an atomic number of 38 whereas yttrium has an atomic number of 39. Because the atomic number increases by one, strontium must gain a proton by emitting a nuclear electron. (Choices A and B) Emission of a positron and electron capture both result in a decrease in the atomic number, which would convert strontium to rubidium. (Choice C) The emission of a gamma ray (high energy photon) does not affect the atomic number or mass of the nucleus, but it does cause a decrease in its energy state. Educational objective: The atomic number of a nucleus but not its atomic mass can be changed by the emission of a nuclear electron or positron, or by electron capture. Electron emission increases the atomic number by one whereas positron emission and electron capture both decrease the atomic number by one.

Passage Nuclear Medicine Uses Radiopharmaceuticals for Disease Treatment and as Tracers