Early nonstochastic effects late stochastic effects
Download
1 / 34

- PowerPoint PPT Presentation


  • 226 Views
  • Updated On :

EARLY NONSTOCHASTIC EFFECTS/LATE STOCHASTIC EFFECTS. Sherer Chapter 6, Reference: Bushong, Chapter 36 and 37 . Review of Dose response curves. Threshold Non threshold Linear quadratic non threshold curve Non linear (s-shaped or sigmoid) . Early, Nonstochastic Effects:.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about '' - oakley


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Early nonstochastic effects late stochastic effects l.jpg

EARLY NONSTOCHASTIC EFFECTS/LATE STOCHASTIC EFFECTS

Sherer Chapter 6,

Reference: Bushong, Chapter 36 and 37


Review of dose response curves l.jpg
Review of Dose response curves

  • Threshold

  • Non threshold

  • Linear quadratic non threshold curve

  • Non linear (s-shaped or sigmoid)


Early nonstochastic effects l.jpg
Early, Nonstochastic Effects:

  • Soon after Rad. Exposure

  • minutes

  • hours

  • days

  • weeks

  • “x-ray burns”


Acute radiation syndromes l.jpg
ACUTE RADIATION SYNDROMES

  • Total body exposure

  • acute exposure in a matter of minutes

  • 100’s or 1000’s of rads


Radiation and mammals l.jpg

200-1000 rads

1000-10,000 rads

10,000 +

Survive a few weeks

3-4 days

few minutes

RADIATION AND MAMMALS


Four stages total body irradiation l.jpg
FOUR STAGESTOTAL BODY IRRADIATION

1) PRODROMAL (NVD SYNDROME)

2)LATENT

3) MANIFEST ILLNESS

4) RECOVERY OR DEATH


1 prodromal l.jpg
1)Prodromal

  • Initial

  • can occur as low as 100 rads

  • within minutes with exposure to 1000 rads

  • nausea, vomiting, diarrhea (NVD)


2 latent period l.jpg
2) Latent period

  • Weeks in low dose

  • Hours in high dose

  • pt appears symptom free

  • lethal effects or recovery is beginning


3 manifest illness l.jpg

A) Hematologic

Gastrointestinal

Cardiovascular

Cerebrovascular/

CNS

Bone Marrow

3) Manifest Illness


A hematologic l.jpg

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

A) HEMATOLOGIC


B gi syndrome l.jpg
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


Cardiovascular l.jpg
CARDIOVASCULAR

  • Not a syndrome

  • Decreased BP

  • Increased pulse rate

  • Acute myocardial insufficiency


C cerebrovascular cns l.jpg
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


Slide14 l.jpg
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


Repair l.jpg
REPAIR?

  • Can occur with sublethal doses but dependent on cell or organ’s potential for recovery.

  • 10% of radiation induced damage - irreparable


Local tissue damage l.jpg
LOCAL TISSUE DAMAGE

  • High doses

  • atrophy of organ

  • Skin-many x-ray pioneers suffered x-ray burns to skin


Skin layers l.jpg
Skin layers

  • Subcutaneous

  • middle layer

  • outer layer (epidermis)

  • accessory structures

    • sensory

    • hair

    • sebaceous

    • sweat


Erythema l.jpg
Erythema

  • 100-300 rad - mild within 1-2 days

  • Q:Dose Response curve?

  • A: Non-linear, threshold

  • Hair loss –epilation

  • Q:Dose Response curve?

  • A: For high dose - Non-linear, threshold

  • low dose – linear, threshold

  • severe necrosis rare


Late somatic effects l.jpg

Late somatic effects

Months or years after whole or partial ARS

OR

Low doses sustained over a couple of years



Risk estimates l.jpg
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


Carcinogenesis l.jpg
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


Match the pathology can use more than once l.jpg

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

Match the pathology (can use more than once)


Extremities l.jpg
EXTREMITIES

  • Amputations

  • radiodermatitis

  • shoe fluoroscopy

  • nuc med. techs


Slide25 l.jpg


American rt s l.jpg
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?


Gonads l.jpg
GONADS

  • Highly sensitive

  • can pass on effects to future generations

  • animal studies/radiotherapy patients, radiation accident victims, convicts

  • oogonia

  • spermatogonia


Testes l.jpg
TESTES

  • 10 rad effect?

  • 200-250 rads effect?

  • 500-600 rads effect?


Ovaries l.jpg
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?


A karyotype is l.jpg

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

A karyotype is


To be continued l.jpg
To Be continued

  • See power point entitled Chapter 8


ad