Test Three

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  1. The TD 5/5 for the whole brain using standard fractionation is approx:
    45 Gy
  2. The period of organogenesis normally occurs between the _______ weeks of fetal development.
    Second through Eighth
  3. The phase of the cellular division most resistant to radiation is the _______ phase.
  4. The immediate symptoms that appear after an acute radiation exposure are called _________ symptoms.
  5. Nausea is associated with the __________ syndrome.
  6. The period over which radiation is delivered is referred to as the _________.
  7. Erythematous skin reactions during fractionated radiation therapy are seen as a result of _____________ in the area.
    Vascular dilation
  8. __________ is an effect of radiation on DNA.
  9. In linear or nonlinear threshold dose-response curves, the response ___________ (may/may not) occur at low doses.
    May not
  10. The average energy deposited per unit of path length to a medium by ionizing radiation as it passes through that medium descibes:
    Linear Energy Transfer
  11. The four R's of radiobiology are:
    • Repair
    • Reoxygenation
    • Repopulation
    • Redistirbution
  12. Lung cancer would be classified as a _________ radiation response.
  13. The standard radiation used to determine RBE is:
    250 keV x-ray
  14. Without medical intervention, a person exposed to a single whole body dose of _____ may die within 10 days.
    10 Gy
  15. Xerostomia can become permanent after doses of:
    40 Gy
  16. Tissue injury ________ as the volume of tissue irradiated increases.
  17. An anticipated response to radiation dose above 55 Gy to the colon is:
  18. Regarding non stochastic effects, effects ________ (are/are not) seen in future generations and the _________ of effects is related to dose.
    • Are NOT
    • Severity
  19. The part of the cell between the membrane and the nucleus is known as the:
  20. The primary function of the cell nucleus is:
    Housing DNA and RNA
  21. The main objectives of radiation protection include prevention of radiation-induced _________ effects and production of radiation-induced _________ effects.
    Deterministic & Stochastic
  22. Somatic effects are limited to the __________ individual.
  23. Ellis' NSD formula is _________ and does not accomodate:
    Total dose = (NSD) T0.11 N0.24

    Different tissue types with varying sensitivity
  24. Regarding the tissue tolerance, as the volume of tissue increases, the tolerance dose _________.
  25. Lethal damage is _________ and leads to ___________.
    • Irreparable
    • Cell Death
  26. ________ phase takes place between G1 and G2.
  27. A cell survival curve usually has a ________ and _________.
    • Shoulder
    • Straight portion
  28. Which dose effect curve implies that if radiation dose is doubled, the biological effect will be doubled?
  29. Cellular growth and development is called:
  30. According to the current recommendations, the guidance levels for cumulative exposures for a 30 year old occupational worker with 3 years of experience.
    300 mSv

    (10 mSv X age in years)
  31. It is recommended that radiation exposure to the fetus should not exceed ______ for the entire gestation period.
    0.5 rem
  32. The roentgen is a unit of measurement that specifies the __________ of air by x-ray or gamma radiation.
  33. The term quality factor (Q) varies with _____________.
    Different types of radiation
  34. Dose equivalent is measured in units of:
    Sievert  (rem)
  35. The organization in the US that is principally responsible for recommending radiation dose limits is the:
  36. The annual radiation dose to the lung from radon is estimated to be:
    200 mrem/year
  37. The annual dose limit for the occupational worker's lens is:
    • 15 rem
    • (150 mSv)
  38. TRUE/FALSE:  Maximum exposure rate at a specific distance from a patient following insertion of radioactive sources can be measured with TLD's.
    • False
    • should be measure with an ion chamber
  39. TRUE/FALSE: The requirement for barrier protection in walls/ceiling from primary radiation is reduced when there is a beam stopper on the treatment unit.
  40. Cataract formation is an example of a ____________ effect.
  41. The amount of energy absorbed in a medium is expressed in units of:
    Gray (Gy)
  42. The quantity directly measured by the TLD is:
    Absorbed dose
  43. The radioactive source inventory room should have a sign that reads:
    Caution Radioactive Material
  44. The _________ describes how much the primary beam is in use.
  45. What is the equation to find the half value layer from linear attenuation coefficient or vice versa?
    Image Upload

    Image Upload
  46. Patients undergoing thyroid ablation with I131 should not be released to leave the facility until survey meter readings reach less than _______ at ______ meter.
    less than 5 mrem/hr at 1 m
  47. A monthly radiation exposure report says an employee received 0.5 Sv. If the source of the exposure were determined to be gamma radiation, the translation to absorbed dose would be:
    0.5 Sv = 0.5 Gy

    Sv = Gy x QF
  48. How many HVL's reduce transmission to 2%?
    • 5.6 HVL's
    •  Image Upload
  49. Three tenth value layers reduce transmission to:
  50. The shielding around stored radioisotopes must be adequate to reduce radiation levels to less than _____ mrem/hr at 1 meter.
    less than 2 mrem/hr at 1 m
  51. What is the transmission formula?
    Image Upload

    • I = final intensity
    • I= Original Intensity
  52. List the half-life, source form and applications of Cesium 137:
    • Cesium 137
    • 30 years
    • Tubes, needles
    • LDR intracavitary, interstitial
  53. List the half-life, source form and applications of Iridium 192:
    • Iridium 192
    • 74 days
    • Seeds
    • LDR interstitial, HDR interstitial & intracavitary
  54. List the half-life, source form and applications of Cobalt 60:
    • Cobalt 60
    • 5.26 years
    • Encapsulated spheres
    • HDR intracavitary
  55. List the half-life, source form and applications of Iodine 125:
    • Iodine 125
    • 60 days
    • Seeds
    • Interstitial
  56. List the half-life, source form and applications of Palladium 103:
    • Palladium 103
    • 17 days
    • Seeds
    • Interstitial
  57. List the half-life, source form and applications of Gold 198:
    • Gold 198
    • 2.7 days
    • Seeds
    • Interstitial
  58. List the half-life, source form and applications of Strontium 90:
    • Strontium 90
    • 28.9 years
    • Plaque 
    • Superficial ocular lesions (pterygium)
  59. List the half-life, source form and applications of Strontium 89:
    • Strontium 89
    • 51 days
    • IV solution
    • Diffuse bone metastases
  60. List the half-life, source form and applications of Iodine 131:
    • Iodine 131
    • 8 days
    • Capsule
    • Thyroid cancer
  61. The protective housing around the cobalt source of the cobalt machine should only allow transmission of ____% of the output.
  62. The source of electrons in a linac is the _________.
    Electron gun
  63. Trimmer bars are attached to the collimator of the cobalt machine to reduce the effects of __________.
  64. The purpose of the _________ is to evenly distribute the energy of the photon beam across a specified area.
    Flattening filter
  65. What is the Penumbra formula?
    Image Upload
  66. The purpose of the _________ in the linac is to monitor dose rate and field symmetry.
    Ion Chamber
  67. The purpose of the Magnetron or Klystron is to:
    produce microwaves for acceleration of electrons in the linac
  68. As the distance from the source increases, the penumbra _________.
  69. As the SCD increases, penumbra _________.
  70. As the source size decreases, penumbra __________.
  71. The field light on the linac is intended to represent the:
    Area of radiation exposure
  72. The scattering foil is placed in the path of the stream of electrons in the linac when programmed to operate in the _______ beam mode.
  73. The cyclotron may produce _________ beams.
  74. The energy range of the early generation superficial therapy machines is:
    50 to 150 kV
  75. Geometric penumbra increases with increasing _______ and _________.
    • Source size
    • Distance from the source
  76. The Fletcher's suite apparatus is an example of __________ brachytherapy.
    Intracavitary LDR
  77. The important QA tests associated with the light field are field size _________ and Light & radiation field __________.
    • Field size ACCURACY
    • Light & radiation field COINCIDENCE
  78. The target to patient skin distance is measured using the __________.
  79. The constancy of a linac must be within ______% of established values.
  80. The x-ray beam in the linac must exhibit flatness within about ____%
  81. Full calibration & overhaul of treatment equipment must be carried out __________.
  82. The exact position of the source in the applicator can be checked by __________.
    Taking a radiograph
  83. Localizing lasers on simulators must be within ______ mm of isocenter.
    2 mm
  84. To check the accuracy of gantry digital readouts, one could use a __________ at ______ degree increments
    Spirit level at 45 degree increments
  85. The Back-up timer, radiation off switch, door interlock and emergency off switch verify the _________ of radiation dose delivery.
  86. The process for test a new linac before putting it into service is known as __________.
    Acceptance testing
  87. Gantry and collimator indicators should be accurate to within ___ degree.
    1 degree
  88. A mechanical distance indicator is used to verify accuracy of the __________
  89. Superficial therapy machines used short treatment distances because percentage depth dose __________.
    Falls off rapidly
  90. The machine that consists of a short metallic cylinder divided into two D-shaped cavities is known as the __________
Card Set:
Test Three
2014-03-28 20:11:15
radiation therapy
Mosbys test three: ch 4, 5, 6
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