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EARLY NONSTOCHASTIC EFFECTS/LATE STOCHASTIC EFFECTS

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EARLY NONSTOCHASTIC EFFECTS/LATE STOCHASTIC EFFECTS Sherer Chapter 7 and 8 Reference: Bushong, Chapter 36 and 37 TESTES 10 rad effect? 200-250 rads effect? – PowerPoint PPT presentation

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Title: EARLY NONSTOCHASTIC EFFECTS/LATE STOCHASTIC EFFECTS


1
EARLY NONSTOCHASTIC EFFECTS/LATE STOCHASTIC
EFFECTS
  • Sherer Chapter 7 and 8
  • Reference Bushong, Chapter 36 and 37

2
Review of Dose response curves
  • Threshold
  • Non threshold
  • Linear quadratic non threshold curve
  • Non linear (s-shaped or sigmoid)

3
Early, Nonstochastic Effects
  • Soon after Rad. Exposure
  • minutes
  • hours
  • days
  • weeks
  • x-ray burns

4
ACUTE RADIATION SYNDROMES
  • Total body exposure
  • acute exposure in a matter of minutes
  • 100s or 1000s of rads

5
RADIATION AND MAMMALS
  • 200-1000 rads
  • 1000-10,000 rads
  • 10,000
  • Survive a few weeks
  • 3-4 days
  • few minutes

6
FOUR STAGES TOTAL BODY IRRADIATION
  • 1) PRODROMAL (NVD SYNDROME)
  • 2)LATENT
  • 3) MANIFEST ILLNESS
  • 4) RECOVERY OR DEATH

7
1)Prodromal
  • Initial
  • can occur as low as 100 rads
  • within minutes with exposure to 1000 rads
  • nausea, vomiting, diarrhea (NVD)

8
2) Latent period
  • Weeks in low dose
  • Hours in high dose
  • pt appears symptom free
  • lethal effects or recovery is beginning

9
3) Manifest Illness
  • A) Hematologic
  • Gastrointestinal
  • Cardiovascular
  • Cerebrovascular/
  • CNS
  • Bone Marrow

10
A) HEMATOLOGIC
  • AKA bone marrow or hemotopoietic syndrome
  • Rad exposure-low
  • Stages
  • Prodromal (NVD)
  • Latent
  • Mitotic stem cells are sterilized
  • pancytopenia-diminished supply of blood cells
  • Death due to dehydration,
  • electrolyte imbalance
  • infection

11
B) GI syndrome
  • 600 rads(6 gy)-1000 rads (10 gy)
  • prodromal - one day
  • latent 3-5 days-deterioration of the lining of
    the GI tract has begun
  • manifest of illness
  • death ( dehydration, anorexia ) 3-4 days
  • cannot prevent progression of syndrome

12
CARDIOVASCULAR
  • Not a syndrome
  • Decreased BP
  • Increased pulse rate
  • Acute myocardial insufficiency

13
C) Cerebrovascular/CNS
  • 5000 RADS
  • Prodromal (nausea and vomiting)
  • latent period 6-12 hours
  • Death occurs within hours- to several days
  • GI and Hemopoietic syndrome occurring
    simultaneously

14
L/D
  • LD 50/30 (Sherer), LD 50/60 (Bushong)
  • used in animals
  • humans tend to survive longer (Chernobyl)
  • see curve (figure 36-1) on page 519 of Bushong or
    LD curve on page 120 Sherer

15
REPAIR?
  • Can occur with sublethal doses but dependent on
    cell or organs potential for recovery.
  • 10 of radiation induced damage - irreparable

16
LOCAL TISSUE DAMAGE
  • High doses
  • atrophy of organ
  • Skin-many x-ray pioneers suffered x-ray burns to
    skin

17
Skin layers
  • Subcutaneous
  • middle layer
  • outer layer (epidermis)
  • accessory structures
  • sensory
  • hair
  • sebaceous
  • sweat

18
Erythema
  • 200 rad within 24-48 hours
  • Desquamation at a higher dose
  • Hair loss epilation-moderate dose
  • High level fluoroscopy studies-10-2Rmin

19
A karyotype is
  • A) study of the genetics of cells
  • B) a new type of karaoke machine
  • C) a chromosome map
  • D) a chromosome aberration
  • Cytogenetic
  • Not!!!
  • Correct answer. Used for cytogenetic analysis
  • Structural damage

20
Late Radiation effects Chapter 7
  • Months or years after whole or partial ARS
  • OR
  • Low doses sustained over a couple of years

21
DOSE RESPONSE CURVES
  • LINEAR NON-THRESHOLD
  • NON LINEAR NON-THRESHOLD
  • LINEAR THRESHOLD
  • NONLINEAR THRESHOLD

22
DOSE RESPONSE CURVES
23
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24
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25
WHAT ARE THE THREE MAJOR TYPES OF LATE SOMATIC
EFFECTS?
26
RISK ESTIMATES
  • Low doses (below 10 rem) effect must be estimated
  • Risk still exists controversial concept
  • Absolute risk specific of excess cancers will
    result due to exposure
  • Relative risk - of excess cancers will increase
    as the natural incidence of cancer increases in
    the population with age

27
Carcinogenesis
  • Distinguishing radiation induced cancer from low
    doses difficult. Why?
  • Epidemiologic studies from high doses are used.
    Examples include
  • Radium watch dial painters
  • Uranium miners
  • Early Radiation workers
  • Infants treated with radiation for enlarged
    thymus
  • Children of Marshall Island
  • Japanese atomic bomb survivors
  • Evacuees from Chernobyl

28
Match the pathology (can use more than once)
  • Radium dial workers
  • Uranium miners
  • Early Medical radiation workers
  • Infants treated for enlarged thymus
  • Children of Marshall Islands
  • Japanese atomic bomb survivors
  • Chernobyl
  • Thyroid
  • Leukemia
  • Breast cancer
  • Bone cancer
  • Skin cancer
  • Lung cancer

29
EXTREMITIES
  • Amputations
  • radiodermatitis
  • shoe fluoroscopy
  • nuc med. techs

30
  • LIFE SPAN SHORTENING
  • CATARCTOGENESIS
  • GENETIC EFFECTS

31
American RTs
  • Ongoing study of 146,000 RTs
  • Higher risk of dying?
  • Higher risk of dying from leukemia?
  • Higher risk of dying from breast cancer?
  • When did these risks become less?

32
GONADS
  • Highly sensitive
  • can pass on effects to future generations
  • animal studies/radiotherapy patients, radiation
    accident victims, convicts
  • oogonia
  • spermatogonia

33
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34
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35
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36
TESTES
  • 10 rad effect?
  • 200-250 rads effect?
  • 500-600 rads effect?

37
OVARIES
  • 10 rad effect?
  • more sensitive in fetus
  • /small children why?
  • 200 rad effect?
  • 500-625 rads compare this range with
    males why the difference?

38
To Be continued
  • See power point entitled Chapter 8
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