Physics Ch 15 Brachytherapy Test 4/12

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Physics Ch 15 Brachytherapy Test 4/12
2013-11-18 22:11:36
radiation therapy physics brachytherapy

Physics Ch 15: Aspects of Brachytherapy Test 4/12
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  1. The time period in which the activity decays to one half the original value:

  2. The average lifetime for the decay of radioactive atoms:
    Mean life
  3. What is the half-life of Radium 226?
    1622 years
  4. What is the half-life of Cobalt 60?
    5.27 years
  5. What is the half-life of Cesium 137?
    30.0 years
  6. What is the half-life of Iridium 192?
    73.83 days
  7. What is the half-life of Iodine 125?
    59.4 days
  8. What is the half-life of Palladium 103?
    16.99 days
  9. What is the half-life of Gold 198?
    2.7 days
  10. What is the half-life of Radon 222?
    3.82 days
  11. Radium 226 decays mainly by ________ _______.
    • Alpha Emission
    • (decays to stable lead)
  12. What is the half-life equation that shows its relationship with the decay constant:
  13. The relationship between activity and half-life is _________ proportional.
  14. It is assumed that 1 mg of Radium will have an activity of:
    1 mCi
  15. Sources that have the same concentration of radioactivity throughout their active length are called:
    Uniform sources
  16. Radium 226 is part of a long decay chain that begins with ________ and concludes with________.
    • Natural Uranium
    • Stable Lead
  17. Most brachytherapy procedures were developed using _________.
    Radium 226
  18. The activity per unit of mass of a radioactive material (C/g):
    Specific Activity

    -dictates the total activity that a small source can have.
  19. The thickness of the source capsule is known as:
    the Filtration
  20. A source which is heavily loaded with activity at one end:
    The Indian Club Source
  21. A source which has heavy loading at both ends with lighter activity concentration in the middle:
    Dumbbell Source
  22. Which isotope has largely replaced radium as the primary isotope for brachytherapy of the uterus and cervix?
    Cesium 137
  23. Which isotope is a popular replacement for Radon 222 in permanent implants and has a very short half-life 2.7 days?
    Gold 198
  24. What was the first radioisotope to be identified and isolated?
    Radium 226
  25. When using both tandem and ovoids in a gynecological implant, the typical resultant dose distribution has the shape of a:
  26. What describes the fraction of the number of atoms that decay per unit time?
    • The decay constant
    • λ
  27. Radium sources are leak tested to check for:
    Radon 222
  28. The most commonly used permanent implant isotopes are:
    • Iodine 125
    • Gold 198
  29. Isotopes with a shorter half life are more likely to be used as __________ implants.
  30. Isotopes with a longer half life are more likely to be used as __________ implants.