SCOTT 10/19

  1. What 3 radiation syndromes is induced by total body exposure
    • Hematopoietic syndrome
    • Gastrointestinal syndrome
    • Cerebrovascular syndrome
  2. What are the 3 specific exposures conditions when dealing with radiation syndromes
    • exposure must be acute (minutes)
    • total body or nnearly total body exposure must occur
    • exposure must be from an external penetrating source rather than ingested, inhaled or implanted radioactive sources
  3. What amount of exposure induces hematopoeitic syndrome?
    100 to 1000 cGy
  4. What does LD50/60 mean?
    • lethal dose 50% in 60 days
    • 50% of the exposed populatioon will be dead in 60 days
  5. what is the lethal dose fro humans estimated to be?
    350 to 450 cGy
  6. Typically who is more resistant males or females?

    the extremely young & old are typically more radiosenstive
  7. although the affected person feel sgood, what is beginning to die
    bone marrow stem cells
  8. Define pancytopenia
    Depression of all blood cell counts
  9. what is the primary cause of death from the hematopoietic syndrome
    infection and hemmoraging after destruction of the bone marrow
  10. what amount of exposure induces the gastrointestinal syndrome
    1000 to 10,000 cGy
  11. the small intestine is the most radiosensitive portion of the digestive system
  12. what amount of exposure induces the cerebrovascular syndrome
    5,000 cGy or more
  13. In the stages of fetal development when is the embyro stage
    day 10 to week 6
  14. In the stages of fetal development when does it become a fetus?
    at the end of week 6
  15. The maximum permissible dose to the fetus during the entire gestational period from occupational exposure of the mother should not exceed 0.5 rem with monthly exposure not exceeding 0.05 rem
  16. what is considered to be the most radiosensitive form of animals and humans
    the embryo & fetus
  17. in reguard to fetal effects of radiation, the prinicpal factors of importance are the dose and the stage of gestation at which it is delivered.
  18. define late effects
    the biologic response of low doses may not be observable for extended periods, ranging from years to generations
  19. late effects are termed as _____ if body cells are involved
    somatic effects
  20. late effects are termed as _____ if reproductive (germ) cells are invovled
    genetic effects
  21. Latent period: The time interval between irradiation and the appearance of a malignancy is known as the latent period
  22. the most important late somatic effects induced by radiation is
  23. radiation is classified as a _____.
    carcinogen, or cancer causing agent
  24. ___ ___ has been implicated as a cause of skin cancer, leuukemia, osteosarcoma, lung cancer, breast cancer, anf thyroid cancer.
    Ionizing radiation
  25. ** Skin cancer: Squamous cell and basal cell carcinomas have been the most frequently observed skin cancers following radiation exposure
  26. Osteosarcoma is:
    bone cancer
  27. Lung carcinoma was once known as
    mountian sickness
  28. Radoon gas: The naturally occuring deposits of radioactive materials in the rocks of the earth decay through a long series of steps until they reach a stable isotope of lead. One of these steps involve radon gas.
  29. ionizing radiation is known as a
  30. DefineĀ  mutation frequency
    the number of spontaneous mutations that occur in each generation of an organism

    Mutation frequency can be increased by any mutagenic agent, including radiation
  31. If the mutation frequency in a generation is doubled by exposure to radiation dose then it is known as
    doubling dose
  32. waht is the goal of radiation therapy for cancer
    to eradicate the tumor while not destaying normal tissues in the treatment field
  33. Growth Fraction refers to the relationship between cancer cells proliferating and those cells resting
  34. The rate at which tumor cells grow depend on these 3 major factors:
    • 1) the division rate of proliferating parenchymal cells
    • 2) the percentage of these cels in the tumor (GF), and
    • 3) the degree of cell loss from the tumor
  35. oxygen tension =
    differing levels of oxygen availability for the tumor cells depending ontheir proximity to functioning blood vessels
  36. Define anoxic
    no oxygen available
  37. Date fromthe animal tumors estimate that approximately 15% or more of the tumor cell population may be hypoxic.
    This is known as what?
    hypoxic fraction
  38. Define fractionation
    therapy treatment are broken up and given in daily doses over an extended period of time but the total dose is the same
  39. The biologic effects on tissue from fractionated radiation therapy depend on the 4 R's of radiation biology.
    These are known as:
    • repopulation
    • redistribution
    • reapir of sublethal damage
    • reoxygenation
  40. define reoxgenation:
    the process by which hypoxic cells gain access to oxygen and become radiosenstive between radiation fractions
  41. IMRT stands for
    intensity modulated radiation therapy
  42. Bladder dose
  43. Esophagus dose
    6000 cGy
  44. Rectum dose
    6000 cGy
  45. what does TD5/5 mean?
    Tissue dose associated with a 5% injury rate within 5 years
  46. what is td5/5 for the brain
    • 5000-6000 cGy
    • necrosis
  47. what is the td5/5 for the eye lens?
    • 500 cGy
    • blindness
  48. what is the td5/5 for the fetus
    • 200 cGy
    • death
  49. What is the td5/5 of the heart
    • 4500 cGy
    • pericarditis and pancarditis
  50. what is the td5/5 of the intestine
    • 4500 cGy
    • ulcer, perforation and hemorrage
  51. what is the td5/5 of the kidney?
    • 1500 cGy
    • acute & chronic nephrosclerosis
  52. what is the td5/5 of the liver?
    • 2500 cGy
    • acute and chronic hepatitis
  53. what is the td5/5 of the lung
    • 3000 cGy
    • acute and chronic pneumonitis
  54. what is the td 5/5 of the spinal cord
    • 4500 cGy
    • Infarction, necrosis
  55. what is the td5/5 of the stomach
    • 4500 cGy
    • Perforation, ulcer, hemorrhage
Card Set
SCOTT 10/19