Rad Science Exam 1 Review

The extrapolation number (n) indicates:

The width of the shoulder of the survival curve

Hematopoietic Syndrome (bone marrow syndrome): select 3 that apply

-The main cause of death is destruction of bone marrow that leads to infection and hemorrhage

- Mean survival time is a few months

- Occurs with doses from 100-1,000 cGy

Stromal compartment is supporting and considered intermediate radiatiosenstive T/F?

True

During Anaphase of mitosis, which of the following occurs?

Centromeres break apart and chromosomes move away from the center

A free radical is:

An atom or molecule with an unpaired electron with no charge

Gross structural changes in chromosomes resulting from radiation damage are referred to as:

Aberrations, lesions, or anomalies

Which of the following best describes Prophase of mitosis?

Chromatin condenses and spindle fibers appear

Therapeutic ratio:

normal tissue tolerance dose/tumor lethal dose

Which phase of acute syndromes can last from a few hours to a few weeks?

Latent Phase

Stradquist's isoeffect curves are related to which of the following?

fractionation

LD 50/30 is:

Radiation dose that would cause 50% of population to die in 30 days

Law of Bergonie and Tribondeau states that radiation is more effective against cells that are: (Select 3 that apply)

-Actively mitotic

-Have a long mitotic future

-undifferentiated

Functional subunits (FSUs) refers to:

The smallest working units of an organ

Acute changes occur within 6 months of treatment: T/F?

True

What marks the completion of cell division in Telophase of mitosis?

The nuclear envelop reappears and cytoplasm divides

Direct Ionization

Damage is caused directly to the DNA

The biologic effect of fractionation depends on the 6R's. what are they?

-Reoxygenation

-Reactivation

-repair

-Repopulation

-Radiosensitivity

-Redistribution

What occurs during the Interphase of mitosis?

Cell grows and replicates chromosomes

Of the 3 Stages of Fetal Development & Radiation Effects on Humans in Utero, the preimplantation stage is from:

Day 0-10 of gestation

The term that relates the biologic response to the quality of radiation is

Relative Biologic Effectiveness

The Manifest Illness of Acute syndromes typically lasts

Hours to months

Deterministic (non-strochastic) effects are:

Radiation responses common to high dose exposure and early symptoms

A cells response to radiation is cell death; characterized by nuclear fragmentation, cell lysis, & phagocytosis of the chromatin bodies by neighboring cells is

apoptosis

What is the likely response to radiation exposure during the preimplantation stage of fetal development?

Embryonic death and resorption

LET is an avg calculated by dividing the energy deposited in the KeV by the distance traveled in micrometers: T/F

True

Stereotactic Radiosurgery (SRS) involves:

High-dose radiation delivered in a single session with percision

D0 is the graphic representation of the cell's radiosensitivity:

True

The most radiosensitive cell cycle is the ____ phase

M

What key event characterizes Metaphase of mitosis?

Chromosome aligns across the center of the cell

Acute side effects include

Inflammation

Radiosensitizers are used to

increase tumor sensitivity to radiation

Of the 3 stages of the fetal development and radiation effects on humans in utero, fetal growth stage is from

end of week 6 of gestation- birth

During which phase does the individual appear symptom-free despite having been exposed to radiation?

Latent phase

Relative Biologic effectiveness (RBE) compares:

The effectiveness of different types of radiation

Stereotactic Ablative Radiotherapy (SABR/SBRT) is characterized by:

High-dose radiation delivered to a very precise target in few fractions

In which phase do the effects of radiation exposure become clearly evident and correlate with the dose received?

Manifest illness phase

What occurs during the interphase of mitosis?

Cell grows and replicates chromosomes

Radioprotectors are agents that

reduce radiation damage to normal tissues

Stochastic effects are

radiation responses are common for low dose exposure and late responses

____ have a higher LET

-protons

-alpha particles

Dq represents:

The slope or dose of the exponential portion of the survival curve

Radiolysis is defined as:

The breakdown of water molecules due to radiation interaction

The law of Bergonie and Tribondeau states that

Radiosensitivity is directly related to cell differentiation and inversely related to division rate

Which phases do irradiated cells reslut in interphase death?

-S

-G2

-G1

The extent of radiation damage can change depending on the cell's external factors is associated with ___

Ancel and Vitemberger

According to the Law of Bergonie and Tribondeau, ionizing radiation is more effective against cells that are:

Actively mitotic and undifferentiated and have a long mitotic future

The latent period is

The time between radiation exposure and observable biological effects

GI Syndrome: Select 3 that apply:

-Mean survival time is 3-10 days

- Occurs with doses 1,000- 10,000 cGy

-Main cause of death is irreparable changes to the GI tact and bone marrow that leads to infection, dehydration, and electrolyte imbalance

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

________________ have low LET. (Select 3 that apply.)

Diagnostic x-ray, electrons, gamma rays

TD 5/5 refers to:

The dose causing 5% complication risk within 5 years

OER is lower for high-LET radiation.

True

Physical factors that influence response to radiation are: (Select 2 that apply.)

-Dose rate

- LET

Deterministic (non-stochastic) effects are

radiation responses common to high dose exposure & early responses.

Limitations to the Nominal Standard Dose equation are: (Select 2 that apply.)

-Based on connective tissue response

- Doesn't account for the irradiated volume

Carcinogenesis as a result of radiation exposure:

Is higher if individuals are exposed in their youth as compared with adulthood.

Linear Energy Transfer (LET) describes:

The rate at which energy is deposited along a radiation path by ionizing radiation

Chronic effects include all but the following:

Erythema

Biologically Effective Dose (BED) is a tool to understand tumor and normal tissue control by using different treatment times and dose fractionation schedules. T/F?

True

What is the Freezing Point of water in Celsius?

0 degrees Celsius

Auger electrons are:

Electrons emitted after inner-shell vacancies are filled

The half-life of Ir-192 is approximately:

73.8 days

What best describes an Alpha Particle?

Radiation that cannot penetrate a sheet of paper

The nuclear force is:

A force that binds nucleons together

The wavelength of a wave is:

Distance between corresponding points on successive waves

What is the maximum number of electrons allowed in the outermost shell of an atom in the third period, n=3?

18

Nuclear binding energy is:

Energy required to hold nucleons together within the nucleus

What does it mean when a substance is Radioactive?

It is composed of atoms with unstable nuclei

X-ray wavelength is:

Inversely proportional to frequency

The acronym ALARA stands for what?

As Low As Reasonably Achievable

The number of protons in the nucleus is called the:

Atomic Number

Radioisotopes:

have unstable nuclei

The difference between electrons and beta particles is:

Their origin

What does Acceleration describe?

Rate of change of velocity with time

What is the SI base unit for measuring Time?

seconds (s)

The Bohr atom model proposes that:

Electrons orbit the nucleus in fixed energy levels

What does Momentum refer to?

Product of mass and velocity

The atomic mass number is equal to:

Protons plus neutrons

All of the following are fundamental particles within an atom, except:

Correct answer:

Photons

What is the half-life of Au-198?

2.7 days.

Which of the following is not one of the four special quantities of radiation measurement?

Affective dose

What is the half-life of I-125?

59.4 days

How is Force defined in physics?

Product of mass and acceleration

The Effective Dose in radiologic science is measured in which unit?

Sievert (Sv)

Wave-particle duality states that:

Matter and radiation exhibit both wave and particle properties

A proton is best described as:

A positively charged particle in the nucleus

Select the base quantities that are building blocks of all other quantities. (Select 3 that apply)

Mass

Length

Time

T/F An atom is the smallest particle that has all the properties of an element.

True

T/F X-rays can be attenuated.

True

What does the "c" represent in the Mass-Energy equation of E = mc2?

Velocity

A single unit of electromagnetic radiation is also called a/an:

Photon

X-rays can be compacted.

False

All elements are arranged into _____ groups as shown in the periodic table of elements.

8

Isotopes are atoms:

Of the same element

A photon is:

A packet (quantum) of electromagnetic energy

What is the definition of Power?

Quotient of work by time

What are 2 principal classes of ionizing radiation?

Particulate and Electromagnetic

The inverse square law states that:

Intensity is inversely proportional to the square of the distance.

The frequency of a wave is:

Number of cycles occurring each second

What wave parameters are needed to define electromagnet radiation? (Select 3 that apply.)

Frequency, Wavelength, Velocity