radiopharmaceuticals n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Radiopharmaceuticals PowerPoint Presentation
Download Presentation
Radiopharmaceuticals

Loading in 2 Seconds...

play fullscreen
1 / 10

Radiopharmaceuticals - PowerPoint PPT Presentation


  • 225 Views
  • Uploaded on

Radiopharmaceuticals. Lab # 7. A radiopharmaceutical is a radioactive compound used for the diagnosis and therapeutic treatment of human diseases. In nuclear medicine nearly 95% of the radiopharmaceuticals are used for diagnostic purposes while the rest are used for therapeutic treatment.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Radiopharmaceuticals


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
    Presentation Transcript
    1. Radiopharmaceuticals Lab # 7

    2. A radiopharmaceutical is a radioactive compound used for the diagnosis and therapeutic treatment of human diseases. • In nuclear medicine nearly 95% of the radiopharmaceuticals are used for diagnostic purposes while the rest are used for therapeutic treatment. • Radiopharmaceuticals usually have minimal pharmacologic effect • In most cases they are used in tracer quantities.

    3. Ideal Radiopharmaceutical • Radiopharmaceuticals should possess some important characteristics • Administered to humans • Several limitations on the detection of radiations by currently available instruments

    4. Easy Availability • Should be easily produced • Inexpensive • Readily available in any nuclear medicine facility. • Complicated methods of production of radionuclides or labeled compounds increase the cost of the radiopharmaceutical. • The geographic distance between the user and the supplier also limits the availability of short-lived radiopharmaceuticals.

    5. Short Effective Half-Life • A radionuclide decays with a definite half-life which is called the physical half-life Tp (or t1/2) • The physical half-life is independent of any physicochemical condition • Radiopharmaceuticals administered to humans disappear from the biological system through fecal or urinary excretion, perspiration, or other mechanisms

    6. Short Effective Half-Life • This biologic disappearance of a radiopharmaceutical follows an exponential law similar to that of radionuclide decay • Every radiopharmaceutical has a biologic half-life (Tb) • The net or effective rate (λe) of the loss of radioactivity is then related to the physical decay constant λp and the biologic decay constant λb. • λ e = λp +‏ λb • Te =Tp X Tb Tp+Tb ‏

    7. Short Effective Half-Life • The physical half-life of 111In is 67 hr and the biologic half-life of 111In-DTPA used for measurement of the glomerular filtration rate is 1.5 hr. What is the effective half-life of 111In-DTPA? • 1.47 hr • Radiopharmaceuticals should have a relatively short effective half-life which should not be longer than the time necessary to complete the study in question

    8. Particle Emission • Radionuclides decaying by a- or b-particle emission should not be used as the label in diagnostic radiopharmaceuticals • Many b-emitting radionuclides such as 131I-iodinated compounds are often used for clinical studies

    9. High Target-to-Nontarget Activity Ratio • For any diagnostic study it is desirable that the radiopharmaceutical be localized preferentially in the organ under study • Activity from nontarget areas can obscure the structural details of the picture of the target organ. • Target-to-nontarget activity ratio should be large.

    10. Thank You