Radiobiology Unit 1

Front 1

the study of effects of ionizing radiation on biologic tissue

Back 1

radiobiology

Front 2

ALARA

Back 2

as low as reasonable achievable

Front 3

ORP

Back 3

optimization for radiation protection

Front 4

BERT

Back 4

background equivalent radiation time

Front 5

energy in transit either as waves or particles

Back 5

radiation

Front 6

radiation that produces electrically charged particles (positive or negative) or IONS as it passes through matter

Back 6

ionizing radiation

Front 7

the only 3 types of electromagnetic radiation that are ionizing

Back 7

x-rays, gamma rays, and cosmic rays

Front 8

type of radiation that all forms are ionizing

Back 8

particulate radiation

Front 9

2 sources of radiation

Back 9

natural 82% and manmade 18%

Front 10

3 natural sources of radiation

Back 10

terrestrial (earth), cosmic (sun, stars), and internal

Front 11

ionizing radiation that comes from radioisotopes that occur naturally and exist in the earth

Back 11

terrestrial

Front 12

5 examples of terrestrial radiation

Back 12

uranium - 238
radium - 226
thorium - 232
iodine - 131
carbon - 14

Front 13

leading source of terrestrial radiation

Back 13

radon gas

Front 14

average U.S. citizen receives approximately how much exposure a year from radon

Back 14

1.98mSv (198mrem)

Front 15

radiation that comes to us from the sun and other stars

Back 15

cosmic radiation

Front 16

cosmic radiation mainly consists of _______ energy photons as a result of interactions in the atmosphere

Back 16

high

Front 17

4 examples of internal radiation

Back 17

potassium - 40 (banana)
hydrogen - 3 (tritium - isotope of hydrogen)
strontium - 90 (deposit in bone and teeth
carbon - 14

Front 18

the transference of energy to matter

Back 18

absorption

Front 19

the amount of energy absorbed per unit mass is called

Back 19

absorbed dose (D)

Front 20

3 x-ray interactions

Back 20

absorbed - energy transferred to tissues (photon deceased, doesn't exist any more)
scatter - some energy transferred
transmitted - no energy transfer

Front 21

lower than 10 kEv, no ionization, less than 20°

Back 21

classical/compton scattering

Front 22

strike inner shell (k) give up all energy, inner shell electron is released (ionization), outer shell electron fills vacancy and doesn't need to be in order (characteristic cascade), secondary radiation is emitted

Back 22

photoelectric interaction

Front 23

x-ray is scattered, electron is released, some energy is transferred, radiation may exit patient and expose others, the bigger the angel of deflection the more energy is lost.

Back 23

compton scatter

Front 24

1.2 mEv required, photon converted into 2 particles, positron and negatron (.51 mEv each), positron is antimatter (everything is reverse, positive has negative charter), 180° from each other

Back 24

pair production

Front 25

minimum of 10 mEv, interact with nucleus, rejected nucleus fragment

Back 25

photodisintegration

Front 26

In 1904, _______________ became the first radiaton mortality after wotking with Thomas Edison on the invention of the fluoroscope

Back 26

Clarence Madison Dally

Front 27

from 1900 to 1930 exposure was measured in the unit of

Back 27

skin erythema dose

Front 28

threshold dose was set at

Back 28

.2R/day

Front 29

the quantity of x-rays in the beam (air)

Back 29

exposure

Front 30

the traditional unit of exposure in air is

Back 30

roentgen

Front 31

The SI unit for exposure is

Back 31

coulomb/kilogram. 1 coulomb=6.3x10^18 free electrons

Front 32

the amount of radiation energy absorbed by any medium (i.e. body tissue)

Back 32

absorbed dose

Front 33

traditional unit for absorbed dose

Back 33

rad (radiation absorbed dose)

Front 34

SI unit for absorbed dose

Back 34

gray
1gy=100rad
1rad=1/100 gy

Front 35

amount of energy transferred from ionizing radiation to matter per unit length of travel

Back 35

LET Linear Energy Transfer

Front 36

equivalent dose uses_________ to adjust absorbed dose to reflect difference in damage produced by different types of radiation. It takes into account varying LET

Back 36

weighting factors

Front 37

equivalent dose=

Back 37

D×Wr, Gy×Wr, or Rad×Wr

Front 38

unit of equivalent dose

Back 38

Rem (radiation equivalent man)

Front 39

SI unit of equivalent dose is

Back 39

Sievert (Sv)

Front 40

takes into account type of radiation and radiosensitivity of irradiated tissues or organs

Back 40

effective dose (EFD)

Front 41

traditional unit for EFD is

Back 41

rem

Front 42

SI unit for EFD is

Back 42

sievert (Sv)
1Sv=100rem

Front 43

Wt=

Back 43

Tissue weighting factor

Front 44

tissue weighting factor for total body and bone surface

Back 44

total body=1
bone surface=.1

Front 45

Traditional unit of collective effective dose

Back 45

man-rem

Front 46

SI unit of collective effective dose

Back 46

persont-sieverts

Front 47

collective effective dose equation

Back 47

dose to a single person × total number of people.
If one of 350 people recieves an effective dose of .20 Sv (20 rem), what is the ColEfD?
350×.2= 70 person-sieverts
or 7000 man-rem

Front 48

traditional unit of measurement for radioactivity

Back 48

curie (Ci)

Front 49

SI unit for radioactivity

Back 49

Becqueral (BQ)

Front 50

1 curie is equal to

Back 50

37 billion BQ

Front 51

half life symbol

Back 51

T1/2