Exam 1 - Radiation Oncology

Question 1

what is radiation?

Answer 1

electromagnetic energy

Question 2

what is ionizing radiation?

Answer 2

radiation with sufficient energy to detach electrons from atoms - ionizing atoms

Question 3

T/F: gamma=xray=photon

Answer 3

true

Question 4

what is the ionization ability & penetration of alpha-rays?

Answer 4

can ionize the atom very readily but penetrability is limited because it isn’t high energy

Question 5

what is the ionization ability & penetration of beta-rays?

Answer 5

greater penetration than alpha-rays but less ionizing than alpha-rays

Question 6

what is the ionization ability & penetration of gamma-rays?

Answer 6

least ionizing but most penetration

Question 7

what diagnostics use gamma rays (electromagnetic radiation)?

Answer 7

radiographs, CT, PET-CT, & radiation therapy

Question 8

what is teletherapy/tomotherapy (external beam)?

Answer 8

showers the patient with photons

Question 9

what is brachytherapy?

Answer 9

radioactive isotype is placed within the patient

Question 10

what is plesiotherapy?

Answer 10

put the probe on top of the area of interest

Question 11

why can’t you be with the patients receiving radiation therapy?

Answer 11

megavoltage photons are used - way too dangerous

Question 12

what are the diagnostic levels of energy typically used?

Answer 12

20-120 kVp

Question 13

what is mAs?

Answer 13

of electrons

Question 14

what is kVp?

Answer 14

energy of xray

Question 15

what happens when you increase mAs?

Answer 15

increase the dose to the patient

Question 16

what happens to your image if you increase kVp?

Answer 16

decrease the diagnostic quality

Question 17

how many volts are in tomotherapy?

Answer 17

6 million volts

Question 18

what are the 3 parts to integrated oncology?

Answer 18

medical, surgical, & radiation oncology

Question 19

in radiation planning, what is contouring?

Answer 19

determining normal structure vs the target for therapy

Question 20

what are the 3 components of radiation protocol?

Answer 20

1. client goals
2. dose required for adequate control for tumor type or palliation
3. limited by dose tolerances of surrounding normal tissues

Question 21

what tumor types are less responsive to radiation?

Answer 21

carcinomas & sarcomas

Question 22

what tumor types are most sensitive to radiation?

Answer 22

round cell tumors

Question 23

what are the rules of thumb for definitive radiation treatment goals as far as dosing?

Answer 23

10-20 fractions - low dose per fraction

high total prescription dose

typically used alone or after surgery

Question 24

what are the rules of thumb for palliative radiation treatment goals as far as dosing?

Answer 24

2-5 fractions - higher dose per fraction

low to moderate total dose

Question 25

what are the goals of definitive radiation treatment?

Answer 25

improve survival in OS, MST, & PFS achieve local tumor control or locoregional control

Question 26

what are the goals of palliative radiation treatment? what about secondary goals?

Answer 26

pain relief, improve quality of life, & improve clinical signs secondary - slow down the progression of the tumor

Question 27

what are the planning techniques for stereotactic radiation therapy?

Answer 27

definitive or palliative setting

Question 28

when would you use stereotactic radiation therapy?

Answer 28

well-defined tumors

Question 29

how is stereotactic radiation therapy defined?

Answer 29

highly conformational, heterogenous dose high ablative dose

Question 30

how many doses are needed in stereotactic radiation therapy?

Answer 30

1-5

Question 31

what is the primary goal for pre-op radiation therapy? what is the secondary goal?

Answer 31

sterilize surgical margins cytoreduction

Question 32

in preoperative radiation therapy, cytoreduction depends on what?

Answer 32

tumor histopathology

Question 33

for short course preop radiation therapy, how many fractions is the rule of thumb?

Answer 33

5 fractions

Question 34

for short course preop radiation therapy, how many fractions is the rule of thumb?

Answer 34

20 fractions

Question 35

T/F: in preop radiation therapy, lower doses are given compared to post-op radiation therapy

Answer 35

true

Question 36

what are the possible risks for pre-op radiation therapy?

Answer 36

increased risk of surgical complications (dehiscence) & more challenging surgery

Question 37

what are the benefits or pre-op radiation therapy?

Answer 37

well-defined tumor for radiation planning less irradiated tissue in the patient associated with improved osteosarcomas in human treatments more treatment options (short course vs. long course)

Question 38

why is CT used for RT planning?

Answer 38

electron density of tissues = HU of CT

Question 39

what is the most common mode of cell death with radiation?

Answer 39

mitotic cell death

Question 40

what is the cellular response to radiation for epithelial, mesenchymal, & round cells?

Answer 40

epithelial - mitotic cell death mesenchymal - mitotic cell death round cell - apoptosis

Question 41

T/F: in radiation therapy, there are not clinically significant side effects

Answer 41

true

Question 42

what is the exception to side effects with radiation therapy?

Answer 42

acute radiation sickness associated with irradiation of large volumes of the body

Question 43

what is the response of sarcomas to radiation?

Answer 43

they are resistant

Question 44

what is the response of round cells to radiation?

Answer 44

they are sensitive to radiation

Question 45

what is the response of carcinomas to radiation?

Answer 45

radiation responsive

Question 46

T/F: side effects from radiation only occur in the radiation field

Answer 46

true

Question 47

what is the most common side effect of radiation?

Answer 47

inflammatory - transient in nature

Question 48

with what kind of radiation therapy are you expecting transient side effects?

Answer 48

definitive radiation therapy

Question 49

what is the best management of radiation therapy side effects?

Answer 49

anti-inflammatories - NSAIDs & steroids prevention of self trauma!!!!

Question 50

what are the chronic side effects of radiation therapy?

Answer 50

fibrosis

Question 51

what radiation therapy type may have an increased risk for chronic side effects?

Answer 51

stereotactic

Question 52

what happens in direct cell target in radiation therapy?

Answer 52

30% single strand or double strand breaks

Question 53

what happens in indirect cell target in radiation therapy?

Answer 53

70% oxygen radical formation from water causes damage & damage is 'fixed' with oxygen

Question 54

what is the compton effect?

Answer 54

***

Question 55

why are photons related to the 'skin spare' effect?

Answer 55

they are indirectly ionizing

Question 56

what is a gray?

Answer 56

1 gy = 1 j/kg unit of absorbed dose

Question 57

what is the formula for radiation protocol?

Answer 57

___ fractions of ___dose/fraction = total prescribed dose fraction = treatment

Question 58

what is included in the initial consult of radiation therapy?

Answer 58

diagnosis, staging, & treatment plan

Question 59

what is included in the radiation planning of radiation therapy?

Answer 59

contouring & computerized planning

Question 60

what is this?

Answer 60

multi-leaf collimator - step & shoot modulation

Question 61

T/F: IMRT & IGRT are the most current historical advances seen in radiation therapy

Answer 61

true - tomotherapy uses IMRT & IGRT