DETERMINISTIC EFFECTS OF RADIATION Flashcards
What are the kinds of acute radiation lethality?
Prodromal Period Latent Period Manifest Illness LD 50/60 Mean Survival Time
What are the different hematologic effects?
Hematopoietic System
Hematopoietic Cell Survival
Whats the anatomic site and threshold dose of death?
Whole Body 2 Gy (200 rad)
Whats the anatomic site and threshold dose of hematologic depression?
Whole Body 250 mGy (25 rad)
Whats the anatomic site and threshold dose of Skin Erythema?
Small Field 2 Gy (200 rad)
Whats the anatomic site and threshold dose of Epilation?
Small Field 3 Gy (300 rad)
Whats the anatomic site and threshold dose of Chromosome Aberration?
Whole Body 50 mGy (25 rad)
Whats the anatomic site and threshold dose of Gonadal Dysfunction?
Local Tissue 100 mGy (10 rad)
ARE THOSE THAT EXHIBIT INCREASING SENSITIVITY WITH INCREASING RADIATION DOSE.
Deterministic Radiation Response
Whats the dose-response relationship in deterministic radiation response?
Non-linear
TO PRODUCE A RADIATION RESPONSE IN HUMANS WITHIN A FEW DAYS TO MONTHS, THE DOSE MUST BE SUBSTANTIAL. SUCH RESPONSE IS CALLED A
EARLY EFFECT OF RADIATION EXPOSURE
EARLY X-RAY PIONEERS DIED FROM THE STOCHASTIC EFFECTS OF X-RAY EXPOSURE.
Acute Radiation Lethality
What relationship does acute radiation lethality follow?
NON-LINEAR, THRESHOLD DOSE-RESPONSE
This is the immediate response of radiation sickness
Prodromal Period
Prodromal Period consists of what symptoms?
acute clinical symptoms
What is the required radiation dose delivered to the total body for signs and symptoms to appear in prodromal period?
above approx 1 GY (100 rad)
How long do the signs and symptoms appear in prodromal period?
within minutes to hours
What are the signs and symptoms of prodromal period?
nausea, vomiting, diarrhea
Aside from nausea, vomiting, and diarrhea
leukopenia - reduction in white blood cells
How long can the prodromal period last?
few hours to a couple days
IT IS THE TIME AFTER EXPOSURE DURING WHICH THERE IS NO SIGN OF RADIATION SICKNESS
Latent period
IN THE LATENT PERIOD, AFTER THE PERIOD OF INITIAL RADIATION SICKNESS, A PERIOD OF ________OCCURS
Apparent well being
Whats the common mistake of the latent period?
IS SOMETIMES MISTAKENLY THOUGHT TO INDICATE AN EARLY RECOVERY FROM A MODERATE RADIATION DOSE
What is acute radiation syndrome?
SEQUENCE OF EVENTS THAT FOLLOW HIGH-LEVEL RADIATION EXPOSURE LEADING TO DEATH WITHIN DAYS OR WEEKS
How many syndromes does acute radiation syndrome have?
3 separate syndromes
What are the 3 syndromes of acute radiation syndrome?
HEMATOLOGIC DEATH
GASTROINTESTINAL (GI) DEATH
CENTRAL NERVOUS SYSTEM (CNS) DEATH
Its radiation dose in in the range of approx 2 Gy to 10 Gy
Hematologic Syndrome
What does the patient feel during hematologic syndrome and how long does it usually occur?
Mild symptoms of prodromal syndrome which may appear in a matter of few hours and may persist fro several days.
It is characterized by reduction in white blood cells, red blood cells and platelets.
Hematologic Syndrome
How long does the latent period last in hematologic syndrome?
4 weeks
If the dose is not lethal in hematologic syndrome, recovery can begin when?
2-4 weeks
Its radiation dose in in the range of approx 10 Gy to 50 Gy
Gastrointestinal Syndrome
What symptoms occur in the gastrointestinal syndrome?
PRODROMAL SYMPTOMS OF VOMITING AND DIARRHEA OCCUR WITHIN HOURS OF EXPOSURE AND PERSIST FOR HOURS TO AS LONG AS A DAY
How long is the latent period of gastrointestinal syndrome
3-5 days
How does GI syndrome manifest illness?
2NDWAVE OF. NAUSEA AND VOMITING FOLLOWED BY DIARRHEA; ANOREXIA AND LETHARGIC
GI death occurs principally because of what?
Because of the severe damage to the cells lining the intestines
When does death occure in GI Syndrome?
4-10 days of exposure
CNS SYNDROME has a radiation does in excess of approx?
50 GY
What happens during the first few minutes of exposure during the CNS syndrome?
SEVERE NAUSEA AND VOMITING BEGINS, USUALLY WITHIN A FEW MINUTES
What happens during the initial onset of the CNS syndrome?
THE PATIENT MAY BECOME EXTREMELY NERVOUS AND CONFUSED, MAY DESCRIBE A BURNING SENSATION IN THE SKIN, MAY LOSE VISION, AND CAN EVEN LOSE CONSCIOUSNESS WITHIN THE FIRST HOUR
Latent period of CNS syndrome?
LAST UP TO 12 HOURS
What is the manifest period of CNS syndrome?
MORE DISORIENTED, LOSE MUSCLE COORDINATION, DYSPNEA, MAY GO INTOCONVULSIVE SEIZURES, EXPERIENCES LOSS OF EQUILIBRIUM, ATAXIA, AND LETHARGY; LAPSES INTO A COMA
Death period of CNS syndrome?
within matter of hours to days
What’s the ultimate cause of death in CNS syndrome?
ELEVATED FLUID CONTENT IN THE BRAIN.
THIS IS THE DOSE OF RADIATION TO THE WHOLE BODY THAT CAUSES 50% OF IRRADIATION SUBJECTS TO DIE WITHIN 60 DAYS.
LD 50/60
What does mean survival time mean?
AS THE WHOLE-BODY RADIATION DOSE INCREASES, THE AVERAGE TIME BETWEEN EXPOSURE AND DEATH DECREASES
What is Local Tissue Damage
WHEN ONLY PART OF THE BODY IS IRRADIATED, IN CONTRAST TO WHOLE-BODY IRRADIATION, A HIGHER DOSE IS REQUIRED TO PRODUCE A RESPONSE
What are the examples of local tissue that can be affected immediately?
Skin
Gonads (testes and ovaries)
Bone Marrow
What relationship does local tissue damage follow?
non-linear threshold-type dose response relationship
How often do the cell linings of the intestines are replaced?
50% everyday
How often are the skin cells replaced?
2% per day
Which cell layer is the most sensitive?
Basal Cell Layer
Basal cell layer are also called as?
Stem Cells
Effects on the skin of radiation follows a what type of relationship?
NONLINEAR, THRESHOLD DOSE-RESPONSE RELATIONSHIP.
2 types of effects of the skin caused by radiation?
Erythema
Desquamation
What is epilation?
Loss of Hair
What are the critically important target organs?
Human Gonads
Human gonads control what?
Fertility and heredity
Which is which?
Spermatogonia
Sperm
Stem cell
Mature Cell
Spermatogonia - stem cell
Sperm - mature cell
What approximate dose can reduce the number of the spermatozoa?
10 rad
Dose of Temporary infertility
200 rad
Dose of Permanent infertility
500 rad
What is the side note when a male patient’s gonads are exposed to 10 rad?
Patient should refrain from procreation for 2 to 4 months.
What is the side note when a male patient’s gonads are exposed to 200 rad?
Commences approx. 2 months after irradiation and persists up to 12 months.
What is the side note when a male patient’s gonads are exposed to 500 rad?
The male patient normally retains his ability to engage in sexual intercourse
Which is which?
Oogonia
Ovum
Stem cell
Mature Cell
Oogonia - stem cell
Ovum - mature cell
What is the approximate dose needed for a female to have a delay in their menstrual period?
10 rad
What’s the dose required for temporary infertility in females?
200 rad
What the dose required for permanent infertility in femalse?
500 rad
What’s the LD for humans?
3.5
When were the radiologic technologists required to have a routine blood exam?
1920s and 1930s
What was included in the examination taken?
- total cell counts
- white blood cell differential count
What consists of the hematopoeitic system?
bone marrow
circulating system
lymphoid tissue
what are lymphoid tissues?
ARE THE LYMPH NODES, SPLEEN, AND THYMUS -PRINCIPAL EFFECT OF RADIATION IS A DEPRESSED NUMBER OF BLOOD CELLS IN THE PERIPHERAL CIRCULATION.
What do the spleen and thymus manufacture?
Lymphocyte
In the child the bone marrow is distributed how?
uniformly throughout the skeleton
In an adult, the active bone marrow is responsible for what?
Producing circulating cells is restricted to flat bones
Role and lifetime of erythrocytes?
RED BLOOD CELLS THAT ARE TRANSPORTATION AGENTS FOR OXYGEN. LIFETIME OF NEARLY 4 MONTHS
Role and lifetime of granulocytes?
SCAVENGER TYPE OF CELLS USED TO FIGHT BACTERIA. LIFETIME ONLY A COUPLE OF DAYS
Role and lifetime of Lymphocytes?
THOSE INVOLVED IN THE IMMUNE RESPONSE. LIFETIME VARIES (HOURS OR YEARS)
Role and lifetime of Thrombocytes?
ALSO CALLED AS PLATELETS AND INVOLVED IN THE CLOTTING OF BLOOD TO PREVENT HEMORRHAGE. LIFETIME OF APPROX. 1 WEEK.
In the hematopoietic cell survial, the principal response is?
DECREASE IN NUMBER OF ALL TYPES OF BLOOD CELLS IN THE CIRCULATION PERIPHERAL BLOOD.
What are the most radiosensitive cells in the body?
Lymphocytes
Spermatogonia
What is cytogenetics
STUDY OF THE GENETICS OF CELLS, PARTICULARLY CELL CHROMOSOMES.
What forms do a damage chromosome take?
Chromatid Deletion
Dicentric Chromosome Abberation
Reciprocal Translocations
When was the human genome mapped?
2000
What is the human genome all about?
IT IS NOW POSSIBLE TO PERFORM MOLECULAR GENETIC COUNSELING AND ADVISE PATIENTS OF THEIR RISK FOR BREAST CANCER, OTHER CANCERS, AND OTHER HEALTH RISKS