Radiation Protection and QA Board Study

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Radiation Protection and QA Board Study
2014-04-07 13:43:58
Candice Radiation Protection QA Board Study

Radiation Protection and QA Board Study
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  1. What is the best material to absorb neutrons
    hydrogen based material
  2. On a CT sim, QA for  the image noise should be done _____ and the spatial resolution done _____ and the contrast resolution done_____
    • daily
    • annually
    • annually (we make New Year's "resolutions" annually)
  3. Photons or xrays that fall into the photoelectric range are best stopped by the
    highest atomic #
  4. Photon energies in the photoelectric range are best attenuated with materials that have a
    large atomic #
  5. Daily simulator localizing laser tolerance is
  6. Proper order of parts that an electron beam travels
    • Electron
    • primary collimator
    • scattering foil
    • ion chamber
    • secondary collimator
    • electron cone
    • patient
  7. When is a solid radioactive material allowed to be thrown out as trash
    When the material has gone through at least 10 half lives and no longer distinguished from back ground radiation
  8. Xray and electron output constancy tolerance is
  9. What is considered an acceptable amt of radiation in an unrestricted area
    25 mrem/year or .25 msv/year
  10. What is the main disadvantage of TLDs? aka lithium fluoride thermo luminescent doismeter
    • They cannot be used over and over
    • ODLs are the ones that can be read many times without removing all of the deposited energy
  11. Occupational exposure of a pregnant woman/embryo/fetus is
    • 5msv
    • .5 rem
  12. Occupational exposure of a worker is
    1 rem per age or 10 msv per age
  13. What is the exposure of an occupational worker's lens
    150 msv or 15 rem
  14. What is the exposure of an occupational worker's skin
    500 msv or 50 rem
  15. What is the exposure for a non-trained radiation worker
    .1 rem per year
  16. What is a low energy dosimeter
    pocket dosimeter
  17. How often are radioactive sources leak tested?
    every 6 months
  18. What are the most sensitive blood cells and show the earliest sign of response to radiation
  19. What depends on the ionization effect to measure radiation intensity
    ion chambers
  20. What sign is needed for radiation above 100mrem/hour
    Caution high radiation area
  21. 1 msv = how many rem
  22. 1000 msv = how many rem and how many SV
    • 100 rem
    • 1 SV
  23. 1 Gray = how many rads and how many cgy
    • 100 rads
    • 100 cGy
  24. 100 mrem = how many rem
  25. .5 SV = how many GY
    .5 GY
  26. Sufficient shielding for a controlled area is no more than _____mrem/week
    100 mrem/week or .1 rem/week
  27. Which effect has no threshold
  28. Give two examples of a prodromal stage of radiation
    nausea and vomitting
  29. When radiation interacts with a film badge, the film _____ proportional to the exposure
  30. What is the most radio sensitive cell
  31. What are measuring devices that verify dose calcs in specific areas of a treated field
  32. Let is measured in
  33. Kinetic energy transferred to a medium is called
  34. Which effect occurs independently of atomic # since the incident photon has such high energy compared to the binding of the electron, thus the photons interact with free electrons
    Compton effect
  35. In SSD techniques, the dose is normlized at
  36. In SAD techniques, the dose is normalized at
    tx depth
  37. MV films have less or more contrast than KV and why
    Less because MV films are resulting from Compton interaction rather than photoelectric
  38. ______ is the biologic effect of a particular type of radiation for a given dose and is compared to the biological effects of _____ xrays for the same dose
    • RBE
    • 250
  39. _____ represents the output of the linac
  40. _____represents the fraction of time in a day a person will be occupying the space behind the barrier
    occupancy factor
  41. _____represents the fraction of time in a tx day in which a beam will be pointed at a particular barrier
    usage factor
  42. B+ decay is when a
    proton is converted to a neutron
  43. Physical size is defined at the ____ isodose line
  44. ____is a fraction of photons attenuated per unit of thickness
    linear attenuation coefficient
  45. What is the threshold for triplet production
    2.044 MV
  46. Can electrons directly ionize
  47. What amplifies microwaves
  48. Bremsstrahlung increases with ____ atomic #
  49. mass attenuation is independent of _____
  50. Photons has to have an energy of ____ in order to strike an electron and scatter 180 degrees
    255 KV
  51. Cobalt 60 decays by giving 2 gamma rays of
    1.17 and 1.33 MeV
  52. Plancks constant is = to
    6.62 X 10-34 J/sec
  53. Alpha particle consists of
    2 protons and 2 neutrons
  54. Alpha particle decay occurs at high atomic #s greater than
  55. What is preferred in HDR afterloading because of the high specific activity and lower photon energy
  56. TMR is independent of
  57. High energy beams have ____ contamination so in vaults with ____MV or higher, shielding for this contamination has to be considered
    • neutron
    • 10
  58. 1 AMU = ___MeV
  59. where does Bremsstrahlung take place
    outside of the nucleus, therefore a linac produces extra nuclear indirectly ionizing radiation
  60. To interact by photoelectric, the interacting photon must have the energy ___ to or ____ the binding energy of the oribiting electron
    = to or greater than
  61. ____ has a dual nature exhibiting wave and quantum model and the electromagnetic fields are perpendicular to each other
    Electromagnetic Radiation
  62. When calibrating ion chambers, what correction factors are needed?
    • barometric pressure
    • volume of the chamber
    • temperatur
  63. Acute radiation effects are more or less sensitive to increased over all tx time
  64. Define TMR
    ratio of dose at any depth to the dose at dmax

    **PDD is the ratio of dose at a point on the CAX relative to the point of maximum dose
  65. A high energy photon strikes an orbital electron and scatters it 180 degress, what is the max energy of the scattered photon
    255 kV
  66. Increasing the MA when performing a CT scan will do what
    • increase the current to the tube and
    • increase the # of photons in the x-ray beam
  67. ____ effects depend on total dose and dose per fraction and ____ effects are more sensitive to increased overall tx time
    • late
    • acute
  68. ____ and ____ are the dependent parameters for skin gap calculations
    • field size
    • tx depth
  69. TMR is dependent on ____,____, and _____ but independent of _____
    • field size
    • tx depth
    • beam energy

  70. _____ are most appropriate for verifying dose in tissue since the lithium fluoride crystals absorb radiation similar to tissue. This is appropriate for verifying dose calcs in specific areas of a txd field
  71. Low energy dosimeter used for personnel monitoring
    pocket dosimeter

    (film badges are more economical)
  72. Device used for recording presence of x radiation, gamma rad, or electron contamination is called
    Geiger Muller
  73. The ____ contains ferrous sulfate, sodium chloride, and sulfuric acid. The monitoring process relies on chemical reaction following exposure
    Frickle dosimeter
  74. Exposure limits for
    Rad worker
    general public
    whole body
    under 18
    non rad worker
    • Rad worker  5 rem
    • general public  .1 rem
    • eye  15 rem
    • skin  50 rem
    • whole body  5 rem
    • embryo/fetus/preg  .5 rem/year or .05rem/month
    • under 18  .5 rem
    • non rad worker  .1 rem
    • hands  50 rem