Radiopharmacy (100% correct answers)

What is a radiopharmaceutical? correct answers A radioactive compound used for a diagnostic study or a therapeutic treatment. Unlike pharmaceuticals ther is no intended effect. What are the characteristics of a diagnostic radiopharmaceutical? correct answers 1) Photon energy between 50-300 keV 2) No particulate radiation (increase pt dose) 3) Practical physical half-life 4) Effective half-life equivalent to the time necessary to perform the study 5) High target to background ratio 6) In vivo suitability/ compatable with the route of administration/ neutral ph. MAKE SURE THINGS ARE STERILE!!! What are the characteristics of a theurapeutic pharmaceutical? correct answers 1) Photon energy is unimportant 2) Particulate radiation preferred 3) Practical isotope half-life 4) High target to background ratio 5) In vivo suitability (compatible material) What are the mechanisms of localization of radiopharmaceuticals? correct answers 1) Passive diffusion 2) Capillary blockade 3) Phagocytosis 4) Compartmental localization 5) Receptor binding 6) Antibody-Antigen binding 7) ion exchange/Active transport 1-4 are mechanical localizations and 5-7 are non-mechanical What are the methods of radionuclide production? correct answers 1) Fission: U-235 spontaneously splits into 2 new atoms, with the release of 2 energetic neutrons. The neutrons strike other nearby U atoms with enough energy and cause them to undergo fission. Generally high specific activty. 2) Target irradiation by neutrons. Low SA 3) Charged particle bombardment (cyclotron). High SA. 4) Radionuclide generators: used to produce short lived radionuclides on-site What is specific activity? correct answers Radioactivty per unit of weight (mCi/gm) What are the requirements for a radionuclide generator? correct answers 1) Easy to operate 2) Eluate free of radionuclidic and chemical impurities 3) Eluate sterile and apyrogenic 4) Daughter isotope should be easy to use as produced by generator 5) Should have a practical life span (14 days)