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Radiation Biology. Cellular Level Cell Sensitivity Radiolysis of Water Direct Effect/Indirect Effect Target Theory Radiation Effect Early Effects Prodromal/Latent period/Manifest Illness Hematopoietic Syndrome GI Syndrome CNS Syndrome Local tissue damage Late Effects

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Radiation biology

Radiation Biology

Cellular Level

Cell Sensitivity

Radiolysis of Water

Direct Effect/Indirect Effect

Target Theory

Radiation Effect

Early Effects

Prodromal/Latent period/Manifest Illness

Hematopoietic Syndrome

GI Syndrome

CNS Syndrome

Local tissue damage

Late Effects

Local Tissue Effect

Life Span shortening

Radiation Protection

Time Distance Shielding

Shield Types

ALARA








Radiation biology

Cell Sensitivity x-rays

  • Early Effect:

  • radiation response occurs within minutes/days after exposure

  • acute radiation syndrome

  • local tissue damage

  • Late Effect:

  • radiation response not observable for months or years

  • leukemia

    • cataracts

  • other cancers

  • local tissue damage

  • Life span shortening

  • genetic damage




  • Radiation biology

    A

    B

    A dose response relationship is produced by extrapolating high dose experimental

    data to low doses.


    Cell sensitivity2

    Diagnostic radiology is almost exclusively concerned with the late of effects for radiation exposure. This assumes a linear non-threshold dose-response relationship. However, no dose is considered safe.

    Cell Sensitivity


    Basic cell structure
    Basic Cell Structure the late of effects for radiation exposure. This assumes a linear non-threshold dose-response relationship. However, no dose is considered safe.

    • Two parts:

      • Nucleus- contains DNA

      • Cytoplasm is 80% water

    • DNA is at risk when a cell is exposed to ionizing radiation


    Cell structure

    Two Basic Cell types the late of effects for radiation exposure. This assumes a linear non-threshold dose-response relationship. However, no dose is considered safe.

    Cell Structure


    Radiation biology

    Radiolysis of Water the late of effects for radiation exposure. This assumes a linear non-threshold dose-response relationship. However, no dose is considered safe.

    Ionization radiation interacts with a water (H2O). Water dissociates into

    2 ions. This process creates free radicals. These are uncharged molecules

    containing as single unpaired electron in outer shell.


    Radiolysis of water

    • H 2 O molecules - the late of effects for radiation exposure. This assumes a linear non-threshold dose-response relationship. However, no dose is considered safe.

    • Ejection of electron = free radical

    • H2 0 2 = hydrogen peroxide

    Radiolysis of Water


    Hoh recombine to h 2 o
    HOH the late of effects for radiation exposure. This assumes a linear non-threshold dose-response relationship. However, no dose is considered safe. + recombine to H2O


    Radiation biology

    Direct/Indirect Effect the late of effects for radiation exposure. This assumes a linear non-threshold dose-response relationship. However, no dose is considered safe.


    Let s play jenga
    Let’s Play the late of effects for radiation exposure. This assumes a linear non-threshold dose-response relationship. However, no dose is considered safe. Jenga !!


    Radiation biology

    Target Theory the late of effects for radiation exposure. This assumes a linear non-threshold dose-response relationship. However, no dose is considered safe.

    Target theory suggests that a key molecule must be

    inactivated. The key molecule is assumed to be DNA.

    • When interaction occurs between radiation and target molecule, it is

    • considered a “hit”

    • An indirect hit has a larger target area because of the mobility

    • of the free radicals

    • Radiation acts randomly.



    Radiation biology

    Radiation Effects Battleship!!!


    Acute radiation syndrome

    Acute Radiation Syndrome – full body exposure given in a few minutes.

    ACUTE RADIATION SYNDROME


    Early effects

    Each Battleship!!!syndrome has 3 main sub-stages

    prodromal stage

    latent stage

    manifest illness

    cell death/repair

    Early Effects


    Total body response to radiation

    • Acute Radiation Syndromes Battleship!!! – full body exposure given in a few minutes.

    • 3 stages of response:

      1. Prodromal -NVD stage (nausea, vomiting, diarrhea)

      2. Latent Period-Feels well while undergoing biological changes

      3. Manifest Illness-Full effects felt, leads to recovery or death

    Total Body Response to Radiation


    3 radiation syndromes

    • Hematologic Battleship!!! : results in infection, hemorrhage & anemia

    • Gastrointestinal : results in diarrhea, nausea & vomiting, fever

    • Central Nervous System : results in convulsions, coma, & eventual death from increased intracranial pressure.

      CNS least sensitive in ADULTS –

      MOST sensitive in the FETUS

    3 Radiation Syndromes


    Cherynobyl fall out
    Cherynobyl Battleship!!! Fall out


    Exposure in soil water

    For Chernobyl: Battleship!!!

    • 11,000 mrem- current background in red zones

    • 12 mrem is your average background radiation.

    • This is a thousand times greater than the normal background level of radiation

    • Approximately 15-20% of babies are born healthy.

    Exposure in soil & water


    Late effects

    • Late Effects Battleship!!!

      • Local Tissue Effect

        • Erythema

        • Cataracts

      • Life Span Shortening

      • Cancers/Malignancies

      • Genetic Effects

    Late Effects


    Late effects of radiation

    Late Effects of Radiation


    Fukushima japan

    Fukushima 50 occupational exposure due to rescue work Battleship!!!

    After reading this article, write your thoughts on the rescue workers in Japan.

    Include allowable exposures to workers, possible acute affects, their prognosis

    for long term health.

    Fukushima, Japan


    Radiation protection

    Radiation Protection


    Cardinal principles of radiation protection

    Cardinal Principles of Radiation Protection Battleship!!!

    Time Distance and Shielding


    Cardinal principles of protection

    Cardinal Principles of Protection


    Radiation biology

    Time Battleship!!!


    Over radiation to skin too much time under beam

    Time Battleship!!!

    Skin burns from 30 min of beam on time

    Over Radiation to SkinToo much time under beam


    Radiation biology

    Acute Localized Radiation Effects Battleship!!!

    The Table 2-2 provides examples of possible radiation effects to skin caused by typical fluoroscopy exposures. Note that patient and technique factors can substantially increase exposure rates, significantly reducing the time necessary for the subsequent effect.

    Table 2-2: Dose and Time to Initiate Localized Radiation Effects

    .7 of an hour is approximately 42 miutes


    Radiation biology

    Distance Battleship!!!


    Radiation biology

    This is an actual arm Battleship!!!tatoo. Now that’s dedication !

    Inverse square law

    Inverse square law

    Inverse square law


    Radiation biology

    Shielding Battleship!!!


    Shielding
    Shielding Battleship!!!

    A lead protective shield is placed

    • Between the x-ray tube and the individuals exposed

    • Absorbs unnecessary radiation


    Types of shielding

    • Contact Battleship!!!

    • Shaped

    • Shadow

    TYPES OF SHIELDING


    Radiation biology

    SHIELD TYPES Battleship!!!


    Breast shield shadow shields

    Shadow Shields Battleship!!!

    Breast ShieldShadow shields


    Shielding1

    1. TECHNOLOGIST . 25 mm LEAD Battleship!!!

    • Lead apron

    • Gloves

    • Thyroid shield

    • Glasses

      2. PATIENT – . 5 mm LEAD

    • Gondal Shielding

    SHIELDING


    Radiation biology

    ALARA Battleship!!!

    As Low As Reasonably Achievable


    Primary barriers
    Primary Barriers Battleship!!!



    Image wisely

    Image Wisely website Battleship!!!

    Image Wisely


    Protecting the patient
    PROTECTING THE PATIENT Battleship!!!

    RISK

    VS.

    REWARD