Rad Science Test 1 Flashcards
1
Q
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.
A
True
2
Q
Of the 3 Stages of Fetal Development & Radiation Effects on Humans in Utero, the organogensis stage is from
A
Day 10 - week 6 of gestation
3
Q
Gastrointestinal (GI) Syndrome:
1. Cause of death
2. Survival time
3. Dose range
A
- Irreparable changes to GI tract and bone marrow
- 3 - 10 days
- 1k - 10k cGy
4
Q
List the cell populations from extremely low radiosensitivity to extremely high radiosensitivity
A
FPM, RPM, Vessels/connective tissue, DIM, VIM
5
Q
Therapeutic Ratio =
A
normal tissue tolerance dose/tumor lethal dose
6
Q
Preimplantation Stage radiation exposure side effects
A
Embryonic death & reabsorption
7
Q
Organogenesis radiation exposure side effects
A
-abnormalities or neonatal death
-like microcephaly, very high risk of mental retardation
-damage to skeleton or sensory organs
8
Q
Fetal Growth Radiation Exposure Stage Symptoms
A
-if exposed, effects are typically present at birth
-high risk of mental retardation
9
Q
T or F :LET and RBE have a direct relationship.
A
True
10
Q
T or F :OER is lower for high-LET radiation.
A
True
11
Q
T or F: Acute changes occur within 6 months of treatment.
A
True
12
Q
What is the most sensitive part of the cell?
A
DNA
13
Q
What is direct Ionization:
A
damage is caused directly to the DNA
14
Q
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
A
Mitotic Delay
15
Q
Stochastic effects are
A
radiation responses are common for low-dose exposure & late responses
16
Q
Law of Bergonie and Tribondeau states that radiation is more effective against cells that:
A
-undifferentiated
-have a long mitotic future
-actively mitotic
17
Q
T or F: Strandquist Isoeffect Curves plot of total dose versus treatment duration.
A
True
18
Q
Deterministic (non-stochastic) effects are
A
radiation responses common to high dose exposure & early responses
19
Q
LD 50/30 is:
A
radiation dose that would cause 50% of population to die in 30 days
20
Q
Acute side effects include:
A
inflammation (erythema)
21
Q
Chronic effects include:
A
Atrophy, Ulceration, Fibrosis
22
Q
What energies (3) have low LET
A
Diagnostic x-rays
Electrons
Gamma Rays
23
Q
Prodromal phase:
1. Time it lasts
2. Symptoms
A
- Minutes to several days
- GI or neurological, Correlate to dose
24
Q
Latent Phase:
1. Time it lasts
2. Symptoms
A
- Hours to weeks
- No symptoms present
25
Manifest Illness Phase
1. Time it lasts
2. Symptoms
1. Hours to months
2. Symptoms evident and correlate with dose
26
The most radioresistant cell cycle is the __________________ phase
S Phase
27
Hematopoietic Syndrome (bone marrow syndrome):
1. Radiation Dose
2. Surival time
3. Main cause of death
1. 100-1K cGy
2. Few months
3. Destruction of bone marrow
28
Cerebrovascular(CV)/Central Nervous System (CNS) syndrome:
1. Radiation Dose
2. Surival time
3. Main cause of death
1. Greater than 5K cGy
2. 3 days
3. Increased pressure in cranium, edema, vasculitis, meningitis
29
A cell response to radiation is cell death; characterized by nuclear fragmentation, cell lysis, & phagocytosis of the chromatin bodies by neighboring cells is _________
Apoptosis
30
Which phases do irradiated cells result in interphase death?
G1
G2
S
31
T or F: LET is an average calculated by dividing the energy deposited in keV by the distance traveled in micrometers
True
32
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)
33
Biological factors that influence response to radiation are:
-position in the cell cycle
-ability to repair sublethal damage
34
Limitations to the Nominal Standard Dose equation are:
-Doesn't account for the irradiated volume
-Based on connective tissue response
35
The ___________ is the death of irradiated cells before these cells reach mitosis
Interphase Death
36
T or F: Amifostine (Ethyol) is a radiosensitizer.
False
37
Chemical factors that influence response to radiation are:
radioprotectors & radiosensitizers
38
The most radiosensitive cell cycle is the ____________ phase
M phase
39
The biologic effect of fractionation depends on the Four R's. What are the four R's?
Repair
Repopulation
Reoxygenation
Redistribution
40
Physical factors that influence response to radiation are:
LET
Dose Rate
41
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
42
Mitotic death is also referred to as ___________.
Reproductive failure
43
Chronic Effects include all but the following:
Erythema
44
Which particles have a higher LET.
-Protons
-Alpha particles
45
Of the 3 Stages of Fetal Development & Radiation Effects on Humans in Utero, the preimplantation stage is from:
Day 0-10 of gestation
46
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
47
T or F: A common free radical is hydrogen peroxide.
True
48
T or F: Stromal compartment is supporting and considered intermediate radiosensitive.
True
49
Interphase (mitosis) characteristics
-cell growth
-replication of chromosomes
-cell not actively dividing.
50
Prophase (mitosis) characteristics
-Chromatin condenses into visible chromosomes
-Chromatids become attached at the
centromere
-Spindle fibers appear
-The nucleolus &
nuclear envelope disappear
51
Metaphase (mitosis) characteristics
-Spindle fibers attach to each chromatid
-Chromosomes align across the center of the cell
52
Anaphase (mitosis) characteristics
-Centromeres break apart
-Chromosomes move away from the center of the cell
-The cleavage furrow appears.
53
Telophase (mitosis) characteristics
-The nuclear envelope and both nuclei appear
-The cytoplasm and organelles divide
equally
-The process of cell division is completed.
54
What is the unit of energy?
Joule
55
The distinct difference between alternating current (AC) and direct current (DC) is that:
DC electron flow is in one direction
56
___________ is the quantity of matter as described by its energy equivalence.
Mass
57
Coulomb's law states that electrostatic force is:
Inversely proportional to the square of the distance between charges
58
Atoms with all electron shells filled are:
chemically stable
59
Ionizing radiation is a special type of radiation that is capable of ____________ an orbital electron from the atom with which it interacts.
removing
60
Half-life of Au-198
2.7 days
61
Half-life of I-131
8 days
62
Half-life of I-125
59.4 days
63
Half-life of Ir-192
73.8 days
64
Half-life of Co-60
5.26 years
65
Half-life of Sr-90
28 years
66
Half-life of Cs-137
30 years
67
T or F: An element is the smallest particle that has all the properties of an atom.
False
68
Electrostatic Laws:
-electric charge distribution is uniform throughout or on the surface
-unlike charges attract, like charges repel
-electrostatic force is directly proportional to the product of the electrostatic charges and inversely proportional to the square of the distance between them
-electric charge of a conductor is concentrated along the sharpest curvature of the surface
69
What is a Conductor
any substance through which electrons easily flow
70
Semi-conductor
a material that under some conditions behaves as an insulator and in other conditions behaves as a conductor
71
Superconductor
property of some materials to exhibit no resistance below a critical temperature
72
Insulator
any material that does not allow electrons to flow through
73
To apply the inverse square law, one must know:
2 distances & 1 intensity
74
Radiation is:
energy transferred
75
X-ray wavelength is Inversely proportional to ...
frequency
76
What are 2 principal class of ionizing radiation?
Particulate and Electromagnetic
77
What is the largest source of human exposure to man-made radiation?
Medical diagnostic radiation
78
What wave parameters are needed to define electromagnet radiation?
-velocity
-frequency
-wavelength
79
The difference between electrons and beta particles is:
their origin
80
Which of the following is not one of the four special quantities of radiation measurement?
Affective Dose
81
Which of the following is an example of electromagnetic radiation?
Visible light
82
What is the rate of change of object's position with time
velocity
83
What is the rate of change of velocity with time
acceleration
84
product of mass and acceleration
force
85
product of mass and the acceleration of gravity
weight
86
product of mass and velocity
momentum
87
product of force and distance
work
88
quotient of work by time
power
89
boiling point in C
100 degrees celsius
90
freezing point in C
0 degrees celsius
91
The principle difference between x-rays and gamma rays is their:
origin
-x-rays come from the electron cloud
-gamma rays come from the nucleus
92
The periodic table presents the elements in the order of:
Atomic number
93
What is Alpha particles "A" number:
4
94
Beta particles characteristics
-light particles with an atomic mass of 0
-carry 1 unit of negative & positive charge
95
A single unit of electromagnetic radiation is also called a/an:
Photon
96
What does the "c" represent in the Mass-Energy equation of E = mc2?
Velocity
97
T or F: X-rays can be compacted
False
98
What is the maximum number of electrons allowed in the outermost shell of an atom in the third period, n=3?
18
99
Isotopes are atoms:
-Of the same element
-with the same number of protons but different numbers of neutrons
100
All of the following are fundamental particles within an atom, except:
photons
101
The Inverse square law states that:
Intensity is inversely proportional to the square of the distance
102
Radiation that cannot penetrate a sheet of paper and has ahelium nucleus is a ___
Alpha particle
103
What has Uncharged radiation and is Highly penetrating
Gamma Ray
104
A substance composed of atoms with unstable nuclei is called
Radioactive
105
What is Radioactivity
-spontaneous emission of energy particles from unstable nuclei
-rate of decay of radioactive material
106
The number of protons in the nucleus is called the:
Atomic number
107
T or F: An atom is the smallest particle that has all the properties of an element
True
108
What are the base quantities that are building blocks of all other quantities:
-length
-time
-mass
109
Radioisotopes have ___ nuclei
Unstable
110
The expression that relates x-ray energy and wave-length through Planck's constant is:
E = hv
111
In approximately how many half-lives will the activity of 10 mCi (0.3 GBq) of I
(Radioactive Half-life= 8 days) be reduced to 0.1 mCi (3.7 MBq)?
10 half-lives
112
All elements are arranged into _____ groups as shown in the periodic table of
elements.
eight
113
Radiology unit for energy
electron volt (eV)
114
Energy emitted & transferred through space is called:
Radiation
115
Matter that intercepts radiation and absorbs part or all of it, is said to be:
irradiated
116
Air Kerma:
-describes a quantity for indirectly ionizing radiation
-NOT a measure of biological damage(unable to show energy absorbed locally)
117
Kerma is
-kinetic energy released in the medium per unit mass at a specific point
-SI unit is Gray (Gy)
118
1 Gray (Gy)=
-100 cGy
-100 rad
119
What is effective dose
-measures the difference responses to radiation in different organs
-accounts for radiation sensitivities of different organs & tissues
120
Exposure measures
the total number of ionizations produced by photons in a unit mass of air
121
Radiation Dose Equivalent:
-calculated for individual organs
-based on the absorbed dose to an organ
-accounts for the effectiveness of the type of radiation
122
Isobar is a
atom that have the same number of nucleons but different numbers of protons & neutrons
123
Isomer
atoms that have the same number of protons and neutrons but a different nuclear energy state
124
Isotone:
atoms that have the same number of neutrons but different number of protons
125
Fuse:
an electrical safety device consisting of or including a wire or strip of fusible metal that melts and interrupts the circuit when the current exceeds a particular amperage
126
Ground:
a large conducting body used as a common return for an electric circuit and as an arbitrary zero of potential
127
Circuit breaker:
a switch that automatically interrupts the current of an overloaded electric circuit
128
Electromagnetic induction:
the process of using magnetic fields to produce voltage, and in a closed circuit, a current
129
Electromechanical devices:
the type of motor used with x-ray tubes is an induction motor which powers the rotation anode of the x-ray tube
130
Anode:
positively charged electrode by which the electrons leave a device
131
Cathode:
negatively charged electrode by which the electrons enter a device
132
What does a Transformer do
changes the intensity of alternating voltage and current in an AC circuit
133
Electromagnetic Radiation:
-oscillating electric & magnetic fields that travel in a vacuum with the velocity of light
-includes x-rays, gamma rays, & some nonionizing radiation
134
Characteristics of non-ionizing Radiation is:
-longer wavelength
-lower frequency
-lower energy
135
Characteristics of ionizing Radiation is:
-shorter wavelength
-higher frequency
-higher energy
136
3 most important regions of the electromagnetic radiation spectrum:
-visible light
-x-ray & gamma radiation
-radiofrequency
137
Radioactive Half-life is:
the time required for a quantity of radioactivity to be reduced to 1/2 its original value
138
Alpha Decay
-consists of 2 neutrons & 2 protons bound together that has been stripped of its 2 electrons
-nuclei with an atomic number (Z) greater than 82
139
Beta- Decay:
-each nucleus emits an electron & antineutrino
-mass number stays the same & atomic number increases by 1
140
Beta+ Decay
-each nucleus emits a positron & a neutrino
-mass number stays the same & atomic number decreases by 1
141
Attenuation is:
the gradual loss of intensity through a medium
142
What is Half-value layer (HVL) definition :
the thickness of some added material required to reduce the beam intensity to half of its original value
143
Coherent(Rayleigh) Scattering
-occurs when the photon bundle passes near an orbiting electron and sets it into motion
-no energy is absorbed, it's redirected
-probable for high atomic number materials & beams <10 keV
144
Photoelectric Effect/Absorption:
-occurs when a photon ejects one of the orbiting electrons
-entire energy of photon is absorbed then transferred
-happens in innermost shells
-the higher the energy, the greater probability of this interaction
145
Compton Effect:
-occurs when a photon interacts with an electron as though it were a free electron
-happens in the outer shells
-encountered electron receives some energy from the photon & is emitted at an angle from the atom
-higher the energy, the lower the probability of this interaction
146
Pair Production:
-as the photon interacts with the strong electric field around the nucleus & gives up all its energy in the process of creating a pair of particles consisting of an electron & positron
-probability of the type of interaction increases with atomic number
-results in complete attenuation of the incident photon
147
Photodisintegration:
-reaction in which the photon strikes the nucleus of the target atom directly & is absorbed
-nucleus emits both neutrons & beta rays
