Rad Science Test 1 Flashcards
T or F :Biologically Effective Dose is a tool to understand tumor and normal tissue control by using different treatment times and dose fractionation schedules.
True
Of the 3 Stages of Fetal Development & Radiation Effects on Humans in Utero, the organogensis stage is from
Day 10 - week 6 of gestation
Gastrointestinal (GI) Syndrome:
1. Cause of death
2. Survival time
3. Dose range
- Irreparable changes to GI tract and bone marrow
- 3 - 10 days
- 1k - 10k cGy
List the cell populations from extremely low radiosensitivity to extremely high radiosensitivity
FPM, RPM, Vessels/connective tissue, DIM, VIM
Therapeutic Ratio =
normal tissue tolerance dose/tumor lethal dose
Preimplantation Stage radiation exposure side effects
Embryonic death & reabsorption
Organogenesis radiation exposure side effects
-abnormalities or neonatal death
-like microcephaly, very high risk of mental retardation
-damage to skeleton or sensory organs
Fetal Growth Radiation Exposure Stage Symptoms
-if exposed, effects are typically present at birth
-high risk of mental retardation
T or F :LET and RBE have a direct relationship.
True
T or F :OER is lower for high-LET radiation.
True
T or F: Acute changes occur within 6 months of treatment.
True
What is the most sensitive part of the cell?
DNA
What is direct Ionization:
damage is caused directly to the DNA
Division Delay is the disruption in the mitotic index, the ratio of the number of mitotic cells to the total # of cells in the irradiated population, caused by irradiated cells and is also known as
Mitotic Delay
Stochastic effects are
radiation responses are common for low-dose exposure & late responses
Law of Bergonie and Tribondeau states that radiation is more effective against cells that:
-undifferentiated
-have a long mitotic future
-actively mitotic
T or F: Strandquist Isoeffect Curves plot of total dose versus treatment duration.
True
Deterministic (non-stochastic) effects are
radiation responses common to high dose exposure & early responses
LD 50/30 is:
radiation dose that would cause 50% of population to die in 30 days
Acute side effects include:
inflammation (erythema)
Chronic effects include:
Atrophy, Ulceration, Fibrosis
What energies (3) have low LET
Diagnostic x-rays
Electrons
Gamma Rays
Prodromal phase:
1. Time it lasts
2. Symptoms
- Minutes to several days
- GI or neurological, Correlate to dose
Latent Phase:
1. Time it lasts
2. Symptoms
- Hours to weeks
- No symptoms present
Manifest Illness Phase
1. Time it lasts
2. Symptoms
- Hours to months
- Symptoms evident and correlate with dose
The most radioresistant cell cycle is the __________________ phase
S Phase
Hematopoietic Syndrome (bone marrow syndrome):
1. Radiation Dose
2. Surival time
3. Main cause of death
- 100-1K cGy
- Few months
- Destruction of bone marrow
Cerebrovascular(CV)/Central Nervous System (CNS) syndrome:
1. Radiation Dose
2. Surival time
3. Main cause of death
- Greater than 5K cGy
- 3 days
- Increased pressure in cranium, edema, vasculitis, meningitis
A cell response to radiation is cell death; characterized by nuclear fragmentation, cell lysis, & phagocytosis of the chromatin bodies by neighboring cells is _________
Apoptosis
Which phases do irradiated cells result in interphase death?
G1
G2
S
T or F: LET is an average calculated by dividing the energy deposited in keV by the distance traveled in micrometers
True
Which llaw states that the extent of radiation damage can change depending on the cell’s external factors is associated with ______________.
Ancel and Vitemberger (P.C.B)
Biological factors that influence response to radiation are:
-position in the cell cycle
-ability to repair sublethal damage
Limitations to the Nominal Standard Dose equation are:
-Doesn’t account for the irradiated volume
-Based on connective tissue response
The ___________ is the death of irradiated cells before these cells reach mitosis
Interphase Death
T or F: Amifostine (Ethyol) is a radiosensitizer.
False
Chemical factors that influence response to radiation are:
radioprotectors & radiosensitizers
The most radiosensitive cell cycle is the ____________ phase
M phase
The biologic effect of fractionation depends on the Four R’s. What are the four R’s?
Repair
Repopulation
Reoxygenation
Redistribution
Physical factors that influence response to radiation are:
LET
Dose Rate
Of the 3 Stages of Fetal Development & Radiation Effects on Humans in Utero, the fetal growth stage is from:
end of week 6 of gestation - birth
Mitotic death is also referred to as ___________.
Reproductive failure
Chronic Effects include all but the following:
Erythema
Which particles have a higher LET.
-Protons
-Alpha particles
Of the 3 Stages of Fetal Development & Radiation Effects on Humans in Utero, the preimplantation stage is from:
Day 0-10 of gestation
The dose of radiation to healthy tissue that will cause a 5% chance of complication
within 5 years of the delivered dose is:
TD5/5
T or F: A common free radical is hydrogen peroxide.
True
T or F: Stromal compartment is supporting and considered intermediate radiosensitive.
True
Interphase (mitosis) characteristics
-cell growth
-replication of chromosomes
-cell not actively dividing.
Prophase (mitosis) characteristics
-Chromatin condenses into visible chromosomes
-Chromatids become attached at the
centromere
-Spindle fibers appear
-The nucleolus &
nuclear envelope disappear
Metaphase (mitosis) characteristics
-Spindle fibers attach to each chromatid
-Chromosomes align across the center of the cell
Anaphase (mitosis) characteristics
-Centromeres break apart
-Chromosomes move away from the center of the cell
-The cleavage furrow appears.
Telophase (mitosis) characteristics
-The nuclear envelope and both nuclei appear
-The cytoplasm and organelles divide
equally
-The process of cell division is completed.
What is the unit of energy?
Joule
The distinct difference between alternating current (AC) and direct current (DC) is that:
DC electron flow is in one direction
___________ is the quantity of matter as described by its energy equivalence.
Mass
Coulomb’s law states that electrostatic force is:
Inversely proportional to the square of the distance between charges
Atoms with all electron shells filled are:
chemically stable