Early Deterministic Radiation Effects on Organ Systems

Question 1

Early Effects

• Biologic effects of radiation that occur relatively ___ after humans receive ___ doses of ionizing radiation
• Substantial evidence of the consequences of such effects comes from ___ laboratory ___ studies and ___ from ___ of some irradiated ___ populations
• Not common in ___ imaging
• Produced by a ___ dose of ionizing radiation

Answer 1

Early Effects

• Biologic effects of radiation that occur relatively SOON after humans receive HIGH doses of ionizing radiation
• Substantial evidence of the consequences of such effects comes from NUMEROUS laboratory ANIMAL studies and DATA from OBSERVATION of some irradiated HUMAN populations
• Not common in DIAGNOSTIC imaging
• Produced by a SUBSTANTIAL dose of ionizing radiation

Question 2

Somatic and Genetic Damage Factors

The amount of somatic and genetic (___) biologic damage a human undergoes as a result of radiation exposure depends on several factors:

1. The ___ of ionizing radiation to which the subject is ___
2. The ability of the ionizing radiation to cause ___ of human ___
3. The amount of body ___ exposed
4. The specific body ___ exposed

Answer 2

Somatic and Genetic Damage Factors

The amount of somatic and genetic (HEREDITARY) biologic damage a human undergoes as a result of radiation exposure depends on several factors:

1. The QUANTITY of ionizing radiation to which the subject is EXPOSED
2. The ability of the ionizing radiation to cause IONIZATION of human TISSUE
3. The amount of body AREA exposed
4. The specific body PARTS exposed

Question 3

Somatic Effects

Depending upon the length of ___ from the moment of irradiation to the first ___ of ___ of radiation damage, the effects are classified as either:

• ___ somatic effects
• ___ somatic effects

Answer 3

Somatic Effects

Depending upon the length of TIME from the moment of irradiation to the first APPEARANCE of SYMPTOMS of radiation damage, the effects are classified as either:

• EARLY somatic effects
• LATE somatic effects

Question 4

Early Radiation Effects on Organ Systems

• ___ somatic effects (formerly called ___ somatic effects)
• Consequences include cell ___
• Effects are ___ related to the ___ received
• As the radiation dose increases, the ___ of these ___ also increases.
• These results have a threshold, a point at which they begin to ___ and ___ which they are ___.
• The amount of biologic damage depends on the actual ___ dose of ionizing radiation.

Answer 4

Early Radiation Effects on Organ Systems

• DETERMINISTIC somatic effects (formerly called NONSTOCHASTIC somatic effects)
• Consequences include cell KILLING
• Effects are DIRECTLY related to the DOSE received
• As the radiation dose increases, the SEVERITY of these EFFECTS also increases.
• These results have a threshold, a point at which they begin to APPEAR and BELOW which they are ABSENT.
• The amount of biologic damage depends on the actual ABSORBED dose of ionizing radiation.

Question 5

Graph Demonstrating the Existence of a Threshold for Early Deterministic Effects

Answer 5

Graph Demonstrating the Existence of a Threshold for Early Deterministic Effects

Question 6

Late Radiation Effects on Organ Systems

Two categories of late effects

• Late ___ ___ effects
• Late ___ (___) effects

Both of these types of late radiation-induced changes are consequences of high-level radiation exposure or of low doses of radiation delivered over a ___ interval of time.

Answer 6

Late Radiation Effects on Organ Systems

Two categories of late effects

• Late DETERMINISTIC SOMATIC effects
• Late STOCHASTIC PROBALISTIC) effects

Both of these types of late radiation-induced changes are consequences of high-level radiation exposure or of low doses of radiation delivered over a LONG interval of time.

Question 7

Early Deterministic Somatic Effects

• Appear within ___, ___, ___, or ___ of the time of radiation exposure
• Requires a ___ dose of ionizing radiation to produce these biologic changes ___ after irradiation
• With the exception of certain lengthy high-dose-rate procedures, ___ ___ examinations do not usually impose radiation doses ___ to cause early deterministic effects.
• High-dose effects include ___, ___, ___, ___, ___ ___, ___ disorders, ___ disorders,___, ___ and ___ desquamation, depressed ___ count in the male, temporary or permanent ___ in the male and female, and injury to the ___ ___ system (at extremely high radiation doses).
• Whole-body dose of ___ Gyt can result in many of these manifestations or ___ damage occurring in ___ (acute radiation syndrome).

Answer 7

Early Deterministic Somatic Effects

• Appear within MINUTES, HOURS, DAYS, or WEEKS of the time of radiation exposure
• Requires a SUBSTANTIAL dose of ionizing radiation to produce these biologic changes SOON after irradiation
• With the exception of certain lengthy high-dose-rate procedures, DIAGNOSTIC IMAGING examinations do not usually impose radiation doses SUFFICIENT to cause early deterministic effects.
• High-dose effects include NAUSEA, FATIGUE, ERYTHEMA, EPILATION, BLOOD disorders, INTESTINAL disorders, FEVER, DRY and MOIST desquamation, depressed SPERM count in the male, temporary or permanent STERILITY in the male and female, and injury to the CENTRAL NERVOUS system (at extremely high radiation doses).
• Whole-body dose of 6 Gyt can result in many of these manifestations or ORGANIC damage occurring in SUCCESSION (acute radiation syndrome).

Question 8

Acute Radiation Syndrome (ARS)
ARS)

• Radiation ___
• Occurs in humans after ___ ___ reception of ___ doses of ionizing radiation delivered over a ___ period of time
• Data from epidemiologic studies of human populations by exposed to doses of ionizing radiation sufficient to cause ARS have been obtained from:
• ___ ___ survivors of Hiroshima and Nagasaki
• Marshall Islanders who were inadvertently subjected to high levels of ___ during an ___ ___ test in 1954
• ___ ___ accident victims such as those injured in the 1986 Chernobyl disaster
• Patients who have undergone ___ ___

Answer 8

Acute Radiation Syndrome (ARS)
ARS)

• Radiation sickness
• Occurs in humans after whole-body reception of large doses of ionizing radiation delivered over a short period of time
• Data from epidemiologic studies of human populations by exposed to doses of ionizing radiation sufficient to cause ARS have been obtained from:
• Atomic bomb survivors of Hiroshima and Nagasaki
• Marshall Islanders who were inadvertently subjected to high levels of fallout during an atomic bomb test in 1954
• Nuclear radiation accident victims such as those injured in the 1986 Chernobyl disaster
• Patients who have undergone radiation therapy

Question 9

Symptoms of ARS and Three Separate Dose-Related Syndromes

• ARS is a collection of symptoms associated with ___ ___ radiation exposure.
• Three separate dose-related syndromes occur as part of the ___ ___ syndrome.

Answer 9

Symptoms of ARS and Three Separate Dose-Related Syndromes

• ARS is a collection of symptoms associated with high-level radiation exposure.
• Three separate dose-related syndromes occur as part of the total body syndrome.

Question 10

Symptoms of ARS and Three Separate Dose-Related Syndromes

• ____ syndrome (___ ___ syndrome)*
• From ___to ___ Gyt
• ___ syndrome*
• Appears at a threshold dose of approximately ___ Gyt and peaks after a dose of ___ Gyt
• ___ syndrome*
• Results from doses of ___ Gyt or more

Answer 10

Symptoms of ARS and Three Separate Dose-Related Syndromes

Hematopoietic syndrome (bone marrow syndrome)

• From 1 to 10 Gyt

Gastrointestinal syndrome

• Appears at a threshold dose of approximately 6 Gyt and peaks after a dose of 10 Gyt

Cerebrovascular syndrome

• Results from doses of 50 Gyt or more

Question 11

Overview of Acute Radiation Lethality

Answer 11

Overview of Acute Radiation Lethality

Question 12

Major Response Stages of ARS

ARS presents in what four major response stages?

Answer 12

• Prodromal, or initial, stage
• Latent period
• Manifest illness
• Recovery or death

Question 13

ARS and of the Atomic Bombing of Hiroshima and Nagasaki

• Human population affected by ARS as a consequence of ___
• Follow-up studies of survivors who did not die of ARS demonstrated ___ ___ and ___ effects of ionizing radiation.
• Created an awareness of the need for a thorough ___ of ARS and appropriate ___ ___ of persons affected

Answer 13

ARS and of the Atomic Bombing of Hiroshima and Nagasaki

• Human population affected by ARS as a consequence of war
• Follow-up studies of survivors who did not die of ARS demonstrated late deterministic and stochastic effects of ionizing radiation.
• Created an awareness of the need for a thorough understanding of ARS and appropriate medical support of persons affected

Question 14

Lethal Dose (LD)

• LD ___/___
• Signifies the whole body dose of radiation that can be lethal to ___% of the exposed ___ within ___ ___
• Quantitative measurement that is fairly precise when applied to ___ ___
• LD ___ for humans may require more than ___ days for its full expression.
  For adult humans the estimated dose is ___ to ___ Gy

Answer 14

Lethal Dose (LD)

• LD 50/30
• Signifies the whole body dose of radiation that can be lethal to 50% of the exposed population within 30 days
• Quantitative measurement that is fairly precise when applied to experimental animals
• LD 50 for humans may require more than 30 days for its full expression.
  For adult humans the estimated dose is 3.0 to 4.0 Gy

Question 15

LD 10/30, LD 50/60, and LD 100/60

• Other measures of lethality
• All of these measures refer to the percentage of subjects who ___ after a certain number of ___. LD ___/___ may be more ___ for humans.
• Value of ___ ___for exposed people

Answer 15

LD 10/30, LD 50/60, and LD 100/60

• Other measures of lethality
• All of these measures refer to the percentage of subjects who die after a certain number of days. LD 50/60 may be more accurate for humans.
• Value of medical support for exposed people

Question 16

Lethal Dose Values

Answer 16

Lethal Dose Values

Question 17

Repair and Recovery

• Cells contain ___ ___ in their biochemistry enabling them to possibly ___ and ___ when they are exposed to ___ doses of ionizing radiation.
• After irradiation, ___ cells begin to ___. This permits an ___ that has sustained ___ damage as a result of radiation exposure to regain ___ or ___ of its ___ ability.
• The amount of ___ damage sustained determines the of organ’s potential for ___.
• In the repair of sublethal damage, ___ cells, which receive more ___, have a better prospect for ___ than do ___ cells that consequently receive fewer ___.
• Repeated radiation injuries have a ___ effect.
• Approximately ___% of radiation damage is ___, whereas the remaining ___% may be ___ over time.

Answer 17

Repair and Recovery

• Cells contain repair enzymes in their biochemistry enabling them to possibly repair and recover when they are exposed to sublethal doses of ionizing radiation.
• After irradiation, surviving cells begin to repopulate. This permits an organ that has sustained functional damage as a result of radiation exposure to regain some or most of its functional ability.
• The amount of functional damage sustained determines the of organ’s potential for recovery.
• In the repair of sublethal damage, oxygenated cells, which receive more nutrients, have a better prospect for recovery than do hypoxic cells that consequently receive fewer nutrients.
• Repeated radiation injuries have a cumulative effect.
• Approximately 10% of radiation damage is irreparable, whereas the remaining 90% may be repaired over time.

Question 18

Local Tissue Damage

• A ___ response in biologic tissue can occur when any part of the human body receives a high radiation dose.
• Significant cell death usually results after such a substantial by ___-body exposure. This leads to ___ of ___ and ___.
• Consequence: ___ and ___ sustaining such damage may lose their ability to ___, or they may ___.
• If recovery occurs, it may be ___ or ___, depending on the type of ___ involved and the ___ of radiation received.
• If organ and tissue ___ fails to occur, ___, or ___, of the irradiated biologic structure results.
• Organ and tissue response to radiation exposure depends on: ___, ___ ___, and ___ ___

Answer 18

Local Tissue Damage

• A destructive response in biologic tissue can occur when any part of the human body receives a high radiation dose.
• Significant cell death usually results after such a substantial by partial-body exposure. This leads to atrophy of organs and tissues.
• Consequence: Organs and tissues sustaining such damage may lose their ability to function, or they may recover.
• If recovery occurs, it may be partial or complete, depending on the type of cells involved and the dose of radiation received.
• If organ and tissue recovery fails to occur, necrosis, or death, of the irradiated biologic structure results.
• Organ and tissue response to radiation exposure depends on: radiosensitivity, reproductive characteristics, and growth rate

Question 19

The Skin

Three layers of the skin:

• ___ (outer layer)
• ___ (middle layer)
• ___ (subcutaneous layer)

Accessory structures include:

• ___ ___
• ___ __
• ___ ___
• ___ ___

Answer 19

The Skin

Three layers of the skin:

• Epidermis (outer layer)
• Dermis (middle layer)
• Hypodermis (subcutaneous layer)

Accessory structures include:

• Hair follicles
• Sensory receptors
• Sebaceous glands
• Sweat glands

Question 20

Effects of Ionizing Radiation on the Skin

What are the effects of ionizing radiation on the skin?

• ___ or loss of hair (___)
• ___ doses of radiation may result in temporary hair loss.
• ___ doses of radiation may result in permanent hair loss.
• Historical evidence of treating skin diseases such as ___
• ___ rays
• Oncology patients receiving ___ radiation therapy treatment have demonstrated significant evidence of ___ damage.
• ___ or ___ interventional procedures that use high-level ___ for ___ periods of time can cause ___ effects on the skin
• Radio___
• ___ evidence
• ___ lesions
• Desquamation

Answer 20

Effects of Ionizing Radiation on the Skin

• Epilation or loss of hair (alopecia)
• Moderate doses of radiation may result in temporary hair loss.
• Large doses of radiation may result in permanent hair loss.
• Historical evidence of treating skin diseases such as ringworm
• Grenz rays
• Oncology patients receiving orthovoltage radiation therapy treatment have demonstrated significant evidence of skin damage.
• Cardiovascular or therapeutic interventional procedures that use high-level fluoroscopy for extended periods of time can cause significant effects on the skin
• Radiodermatitis
• Historical evidence
• Cancerous lesions
• Desquamation

Question 21

Development of the Male and an imprint Female Germ Cells

Answer 21

Development of the Male and an imprint Female Germ Cells

Question 22

Effects of Ionizing Radiation on the Reproductive System

• ___ of human germ cells
• Gonadal dose that can ___ the male sperm population or cause a genetic mutation in future generations
• Gonadal dose that may ___ or ___ ___ in the female
• Differences in the way the ___ of the male and the ___ of the female respond to ionizing radiation exposure
• Gonadal dose of ionizing radiation that will cause ___ sterility in the male and in the female
• Gonadal dose of ionizing radiation that will cause ___ sterility in the male and in the female

Answer 22

Effects of Ionizing Radiation on the Reproductive System

• Radiosensitivity of human germ cells
• Gonadal dose that can depress the male sperm population or cause a genetic mutation in future generations
• Gonadal dose that may delay or suppress menstruation in the female
• Differences in the way the testes of the male and the ovaries of the female respond to ionizing radiation exposure
• Gonadal dose of ionizing radiation that will cause temporary sterility in the male and in the female
• Gonadal dose of ionizing radiation that will cause permanent sterility in the male and in the female

Question 23

Hematologic Effects

• Radiation protection programs have long since abandoned relying on hematologic ___ as a means for ___ imaging personnel to assess whether they have sustained any degree of radiation ___ from occupational exposure.
• During the 1920s and 1930s, ___ blood count were the only means of ___ workers engaged in radiologic practices.
• Whole-body dose of ionizing radiation as low as ___ Gyt would produce a measurable hematologic ___.
• Consequences of hematologic depression for the human body
• Use of personnel ___ for ___ of occupational exposure made the practice of requiring ___ blood counts for monitoring radiation damage ___.

Answer 23

Hematologic Effects

• Radiation protection programs have long since abandoned relying on hematologic depression as a means for monitoring imaging personnel to assess whether they have sustained any degree of radiation damage from occupational exposure.
• During the 1920s and 1930s, periodic blood count were the only means of monitoring workers engaged in radiologic practices.
• Whole-body dose of ionizing radiation as low as 0.25 Gyt would produce a measurable hematologic depression.
• Consequences of hematologic depression for the human body
• Use of personnel dosimeters for monitoring of occupational exposure made the practice of requiring periodic blood counts for monitoring radiation damage obsolete.

Question 24

Hematopoietic System

• Consists of ___ ___, ___ ___, and ___ organs (___ nodes, ___, and ___ gland)
• Cells of this system all develop from a ___ ___ cell, the ___ ___ cell.
• Radiosensitivity of ___, ___, ___, ___ (___), and ___.

Answer 24

Hematopoietic System

• Consists of bone marrow, circulating blood, and lymphoid organs (lymph nodes, spleen, and thymus gland)
• Cells of this system all develop from a single precursor cell, the pluripotential stem cell.
• Radiosensitivity of lymphocytes, neutrophils, granulocytes, thrombocytes (platelets), and erythrocytes.

Question 25

Cytogenetic Effects

• Cytogenetics is the study of cell ___ with emphasis on cell ___.
• A cytogenetic analysis of ___ may be accomplished through the use of a ___ map called a ___. This map consists of a ___ or ___.
• ___ is the phase of cell division in which ___ damage caused by radiation exposure can be evaluated. ___ aberrations and ___ aberrations have been observed at ___.

Answer 25

Cytogenetic Effects

• Cytogenetics is the study of cell genetics with emphasis on cell chromosomes.
• A cytogenetic analysis of chromosomes may be by accomplished through the use of a chromosome map called a karyotype. This map consists of a photograph or photomicrograph.
• Metaphase is the phase of cell division in which chromosome damage caused by radiation exposure can be evaluated. Chromosome aberrations and chromatid aberrations have been observed at metaphase.