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 1

    Image Upload 2
  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 3
  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 4

    • 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 5
  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
Mosbys test three: ch 4, 5, 6
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