Isotopes Used in Nuclear Medicine to Know for Intro to Applied Nuclear Physics

Isotopes play a crucial role in nuclear medicine, enhancing diagnostic and therapeutic techniques. Key isotopes like Technetium-99m and Iodine-131 are vital for imaging and treatment, showcasing the practical applications of nuclear physics in healthcare.

  1. Technetium-99m

    • Widely used in diagnostic imaging, particularly in SPECT (Single Photon Emission Computed Tomography).
    • Has a half-life of 6 hours, allowing for timely imaging while minimizing radiation exposure.
    • Emits gamma rays, which are ideal for imaging due to their ability to penetrate tissues.
  2. Iodine-131

    • Primarily used for the treatment of thyroid disorders, including hyperthyroidism and thyroid cancer.
    • Has a half-life of 8 days, which allows for effective treatment while reducing long-term radiation exposure.
    • Emits both beta and gamma radiation, making it useful for both therapeutic and diagnostic purposes.
  3. Fluorine-18

    • Commonly used in PET (Positron Emission Tomography) scans for cancer detection and monitoring.
    • Has a short half-life of about 110 minutes, necessitating on-site production and rapid use.
    • Emits positrons, which interact with electrons to produce gamma rays, providing high-resolution images.
  4. Gallium-67

    • Utilized in imaging to detect infections, tumors, and certain types of cancer, particularly lymphoma.
    • Has a half-life of 78 hours, allowing for delayed imaging after administration.
    • Accumulates in areas of inflammation and tumors, aiding in diagnosis.
  5. Thallium-201

    • Primarily used in myocardial perfusion imaging to assess heart function and blood flow.
    • Has a half-life of 73 hours, providing flexibility in imaging schedules.
    • Emits gamma radiation, which is useful for detecting areas of reduced blood flow in the heart.
  6. Indium-111

    • Used in various diagnostic applications, including labeling white blood cells for infection detection.
    • Has a half-life of 2.8 days, allowing for imaging over a few days post-injection.
    • Emits gamma rays, facilitating imaging of specific organs and tissues.
  7. Xenon-133

    • Employed in lung ventilation studies to assess pulmonary function and detect abnormalities.
    • Has a half-life of 5.2 days, allowing for imaging over a short period.
    • Emits gamma radiation, which is useful for real-time imaging of lung ventilation.
  8. Iodine-123

    • Used in thyroid imaging and for evaluating thyroid function, particularly in diagnosing thyroid cancer.
    • Has a half-life of 13 hours, providing a balance between imaging time and radiation dose.
    • Emits gamma rays, making it suitable for SPECT imaging.
  9. Samarium-153

    • Primarily used for pain relief in patients with bone metastases, providing palliative care.
    • Has a half-life of 46.3 hours, allowing for effective treatment while minimizing side effects.
    • Emits beta particles, which target bone tissue and help alleviate pain.
  10. Yttrium-90

    • Used in radioembolization for treating liver cancer and in certain types of targeted radiotherapy.
    • Has a half-life of 64 hours, allowing for localized treatment with minimal systemic exposure.
    • Emits beta radiation, which is effective for destroying cancer cells in targeted areas.


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© 2025 Fiveable Inc. All rights reserved.
AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.