C. biological effects of radiation part 2

Question 1

Dose-response relationships are represented by a

Answer 1

graph

Question 2

Dose- response graphs show information on the cells response to radiation and cell survival in the

Answer 2

presence of radiation

Question 3

Dose- response graphs are either

Answer 3

linear or nonlinear

Question 3

___ graphs represent a response that is not proportional to the dose recieved

Answer 3

non- linear

Question 4

____ graphs represents a response that is directly proportional to the dose recieved

Answer 4

linear

Question 5

________ on a Dose-response graph represents a dose after which only 37 percent of the cell population will survive

Answer 5

Do or D37

Question 6

Cells that are _____ have a low Do because it takes a lower dose to kill all but 37 percent of cell the cell population

Answer 6

radiosensitive

Question 7

Cells that are ______ have a high Do because it takes a higher dose to kill all but 37 percent of the cell population

Answer 7

radioresistant

Question 8

_______ is the number of cells or the target on dose response graph

Answer 8

extrapolation number (n)

Question 9

The extrapolation number (n) is usually about

Answer 9

2-10

Question 10

___ is the quasi-threshold dose, which represents the cells capability to repair

Answer 10

Dq

Question 11

Dq is also known as the

Answer 11

shoulder region

Question 12

Graphs with multipl Dq/ shoulder regions represent

Answer 12

multiple factors

Question 13

_____ is the most sensitive part of the cell

Answer 13

DNA

Question 14

where is DNA located

Answer 14

nucleus

Question 15

When radiation interacts with the target it is called a

Answer 15

direct hit

Question 16

Law of _________: explains the effect of radiation is greater for cells that divide rapidly, cells that are immature with long mitotic future, and undifferentiated

Answer 16

Bergonie and Tribondeau

Question 17

Stem cells are ______ than mature cells

Answer 17

more radiosensitive

Question 18

Blood forming cells are _____ because of their rapid division rate

Answer 18

more radiosensitive

Question 19

_______ = the extent of radiation damage can change depending on the cells external factor before, during, or after delivery of radiation

Answer 19

Ancel and Vitemberger

Question 20

________ is the rate that energy is deposited through matter as it travels through it

Answer 20

Linear energy transfer (LET)

Question 21

LET is another expression of

Answer 21

radiation quality

Question 22

X rays and gamma rays have ___ LET

Answer 22

low - goes farther

Question 23

Protons and alpha particles have ___ LET

Answer 23

high - goes shorter distances

Question 24

On a dose- response relationship graph, high LET is represented by a steeper curve and shoulder is either smaller than normal or nonexistent because more cells are

Answer 24

killed faster do not have a chance of repair

Question 25

_________ = the ability for the type of radiation to produce biological damage

Answer 25

Relative biological effectiveness (RBE)

Question 25

Higher LET= ___ RBE

Answer 25

higher

Question 26

Lower LET = __ RBE

Answer 26

lower

Question 27

let equations ??

Question 28

Examples of radiation types with low RBE are

Answer 28

diagnostic x-rays, gamma rays, MV x-rays, electrons, etc.

Question 29

Examples of radiation types with higher RBE are

Answer 29

heavy nuclei, alpha particles, fast neutron, etc.

Question 30

Therapeutic ratio equation is

Answer 30

normally tissue tolerance dose / tumor lethal dose

Question 31

On the linear accelerator, lower dose rates cause less damage than

Answer 31

higher dose rates

Question 31

ideally, tumor lethal dose should be less than the normal tissue dose to avoid

Answer 31

damage to healthy tissue

Question 32

High dose rates cause more

Answer 32

side effects more rapidly

Question 33

TBI uses ___ dose rates

Answer 33

high

Question 34

___ is the radiation dose than would cause 50% of population to die in 30 days

Answer 34

LD 50/30

Question 35

LD 50/30= ___ SV

Answer 35

4-5

Question 36

The presence of oxygen during a radiation treatment will greatly increase the

Answer 36

radiosensitivity of the cell

Question 37

Tissues are more radiosensitive when in an

Answer 37

oxygenated, or aerobic, state

Question 38

Typically, cells within a tumor are in an ___ state

Answer 38

Anoxic - no oxygen

Question 39

_____ for xrays is 2.5-3.0 in human cells

Answer 39

Oxygen enhancement ratio (OER)

Question 40

OER is higher for ___ LET radiation

Answer 40

Low

• due to high LET radiation already being very damaging

Question 41

OER is lower for ___ LET radiation

Answer 41

high

Question 42

A ______ effect is when radiation hits the target (DNA)

Answer 42

direct

Question 43

A ____ effect is when radiation first hits water within the cell, which then damages DNA

Answer 43

indirect

Question 44

Indirect effect lead to

Answer 44

radiolysis and free radicals in the cell

Question 45

WHat is a common free radical in the cell

Answer 45

hydrogen peroxide ( H2O2)

Question 46

Free radicals can lead to damage of

Answer 46

DNA

Question 47

Chromosome damage can be

Answer 47

single or double strand breaks

Question 48

_______ breaks can lead to dicentric fragments, acentric fragments, translocation and/or ring formation

Answer 48

single strands

Question 49

_____ breaks can lead to deletions and inversion

Answer 49

double - stand

Question 50

A cell response to radiation is cell death, which is known as

Answer 50

aptosis

Question 51

The most radiosensitive cell cycle is th

Answer 51

M phase (also end of G2)

Question 52

The most radioresistant cell cycle is the

Answer 52

S phase