Ch6 LET and RBE

Question 1

Electromagnetic waves can break ___

Answer 1

Chemical bonds

Question 2

What is particulate radiation

Answer 2

Emission of energized particles from the nucleus during radio active decay

Question 3

What is excitation

Answer 3

Raising of a electron WITHOUT the ejection of an orbital electron

Question 4

What is Ionization

Answer 4

Removal of an electron resulting in a ion pair

Question 5

In ionization what charge is the newly freed electron

Answer 5

Negative

Question 6

What energy does modern equipment use (Mv)

Answer 6

4-25 MV energy

Question 7

Ionizatioan results in the ___ ___ of a radiation beam

Answer 7

biological effictiveness

Question 8

Electromagnetic and particulate both (2)

Answer 8

• Propel energy through space
• Travel at the speed of light

Question 9

Electromagnetic particles consists of

Answer 9

Photons

Question 10

Electromagnetic have a ___ penetrability

Answer 10

Higher

Question 11

Electromagnetic examples (3)

Answer 11

• Radiowaves
• Microwaves
• Infrared

Question 12

Photons have no (2)

Answer 12

• Mass
• Charge

Question 13

Particulate particles can be

Answer 13

can be charged or uncharged

Question 14

Particulate have a ___ penetrability

Answer 14

Lower

Question 15

Examples of Particulate particles (2)

Answer 15

• Alpha particles
• Beat particles

Question 16

What does LET measure?

Answer 16

The rate at which energy is transformed from souce to tissue

Question 17

Densely ionizing has ___ LET

Answer 17

High

Question 18

Sparsely ionizing has ___ LET

Answer 18

Low

Question 19

Examples of densely ionizing particles

Answer 19

Alpha particles and neutrons

Question 20

Examples of low LET rays

Answer 20

• Xray
• Gamma ray

Question 21

LET Alpha particle
- Charge
- AMN
- LET

Answer 21

• 2
• 4
• Highest

Question 22

LET Neutron
- Charge
- AMN
- LET

Answer 22

• 0
• 1
• High

Question 23

Direct interatction is more likely with ___ LET radaition

Answer 23

High

Question 24

What is the principle interaction in the body

Answer 24

Radiolysis of water

Question 25

Alpha particles consists of

Answer 25

2 protons and 2 neutrons

Question 26

LET Proton - Charge - AMN - LET

Answer 26

- 1 - 1 - High

Question 27

Alpha particles are emmitted during the decay of

Answer 27

radionuclides

Question 28

Direct interactions provide kinetic energy that can (2)

Answer 28

- Disrupt the atomic structure - Produce biological change

Question 29

Direct interactions results from

Answer 29

Ionization or excitation of the target

Question 30

Examples of high LET particles (3)

Answer 30

- Protons - Electrons - Neutrons

Question 31

Direct action produces damage by

Answer 31

Direct ionization of the critical target

Question 32

X-rays and gamma rays produce ___ ionization

Answer 32

Indirect

Question 33

X-rays and gamma rays do not produce ___ and ___ damage themselves

Answer 33

- Chemical - Biological

Question 34

Ionization of water and the formation of __ and __ ion pair. AND the formation of __/__ free radicals are extremely reactive

Answer 34

- H+ and OH- - OH/H

Question 35

The major factor of damage is the ___, Via ___

Answer 35

OH radical via indirect action in the cell**.

Question 36

Does indirect action or direct action have a greater probability of radiation damage? Why?

Answer 36

- Indirect action - there is more water in the body than any other components. body is 80% water & chances of spreading is more.

Question 37

what does LET stand for?

Answer 37

linear energy transfer

Question 38

Indirect interactions primarily occure through ionization of ___

Answer 38

water

Question 39

Indirect interactions produce

Answer 39

Free radicals

Question 40

Define Ion

Answer 40

Atom or molecule that is electrically charged because it has lost an electron

Question 41

Define free radical

Answer 41

Fragment of an atom or molecule that has a unpaired electron in the outer shell making it highly reactive

Question 42

Define LET

Answer 42

Rate at energy is deposited, as a charged particle travels through matter, by a particular type of radiation

Question 43

LET is dependant on (2)

Answer 43

- Mass - Charge

Question 44

Relative biologic effect is based on

Answer 44

differing rates of energy loss

Question 45

Equal ___ of radiation differing in LET, produces ___ ___ of the same ___ ___

Answer 45

- Doses - Varying degree - Biologic responce

Question 46

What is "Relative" Biological Effect

Answer 46

The ability of different types of radiation to produce the same biological responce

Question 47

RBE= the comparison of a dose of __ ___ to the dose of ___ kev x-ray that produces the ___ ___ response

Answer 47

- Test radiation - 250 - Same biologic

Question 48

Different "doses" of differing LET radiation will produce the

Answer 48

SAME DEGREE of a biologic effect.

Question 49

different LET type radiation will produce the same degree of biologic effect but

Answer 49

at different doses

Question 50

RBE formula

Answer 50

(Dose) of 250 Kev / (Dose) of test radiation

Question 51

Standard formula

Answer 51

(Dose) of 250 Kev / 1.0

Question 52

RBE geater than 1.0 indicates

Answer 52

Higher LET

Question 53

RBE - 1.0 - 1.5 - 2.0

Answer 53

- Same effect -50% higher RBT - 100% higher RBT (Double effect)