1. EARLY NONSTOCHASTIC EFFECTS/LATE STOCHASTIC EFFECTS
Sherer Chapter 6,
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
100’s or 1000’s 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 Death due to dehydration, electrolyte imbalance
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 organ’s 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 100-300 rad - mild within 1-2 days Q:Dose Response curve?
A: Non-linear, threshold
Hair loss –epilation
A: For high dose - Non-linear, threshold
low dose – linear, threshold
severe necrosis rare

19. Late somatic effects Months or years after whole or partial ARS OR
Low doses sustained over a couple of years

20. WHAT ARE THE THREE MAJOR TYPES OF LATE SOMATIC EFFECTS?

21. 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

22. 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

23. 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

24. EXTREMITIES Amputations radiodermatitis shoe fluoroscopy
nuc med. techs

25. LIFE SPAN SHORTENING
CATARCTOGENESIS
GENETIC EFFECTS

26. American RT’s Ongoing study of 146,000 RT’s Higher risk of dying?
Higher risk of dying from leukemia?
Higher risk of dying from breast cancer?
When did these risks become less?

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

31. TESTES
10 rad effect?
rads effect?
rads effect?

32. OVARIES 10 rad effect? more sensitive in fetus /small children why?
rads compare this range with males why the difference?

33. 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

34. To Be continued
See power point entitled Chapter 8