Radiation Oncology

Question 1

RT is a _____ tx

Answer 1

locoregional

Question 2

surgery is a ____ tx

Answer 2

local

Question 3

chemo is a ____ tx

Answer 3

systemic

Question 4

about ____ % of all incident cancer cases require RT at some point

Answer 4

50%

Question 5

modern RT uses high energy ___

Answer 5

xrays

Question 6

what is the logic behind using xrays to kill cancer cells

Answer 6

Main target of ionizing radiation = cell’s nuclear DNA
When enough DNA damage accumulates = cells can no longer divide = cell death
Cancer cells can not repair DNA damage as effectively as normal tissues = preferentially killed by RT

Question 7

what is the most common type of RT

Answer 7

external beam

Question 8

the higher the energy the _____ the radiation penetrates into target tissue

Answer 8

deeper

Question 9

what are the 2 types of RT

Answer 9

external beam
brachytherapy

Question 10

what is brachytherapy

Answer 10

internal radiotherapy from radioactive implants that may be permanent or removable
intent is to deliver high dose radiation to tumor while limiting absorption from surrounding tissues

Question 11

how often do you get RT

Answer 11

5 days a week

Question 12

2 RT treatments = ____ fraction

Answer 12

2

Question 13

1 Gy = ____ cGy = ____ rad

Answer 13

1gy = 100cGy = 100rad

Question 14

what are radiosensitizers?

Answer 14

chemicals that increase biologic effects of RT

Question 15

what are some chemo agents that are also radiosensitizers

Answer 15

5FU
cisplatin

Question 16

5FU is used with RT for ______ cancer

Answer 16

rectal

Question 17

cisplatin is used with RT for _________________________ cancer

Answer 17

head/ neck
lungs
cervical
bladder

Question 18

RT to ______ if Post lumpectomy, lymph node negative

Answer 18

breast

Question 19

RT to ______ if Post lumpectomy, lymph node positive

Answer 19

breast + regional lymph node

Question 20

RT to ______ if Post mastectomy, lymph node positive

Answer 20

entire chest region + regional lymph nodes

Question 21

RT to ______ if, low risk prostate cancer

Answer 21

prostate only

Question 22

RT to ______ if, intermed risk prostate cancer

Answer 22

prostate + proximal seminal vesicles

Question 23

RT to _______ if high risk prostate cancer

Answer 23

prostate + proximal seminal vesicles + pelvic lymph node

Question 24

____________, a form of IMRT (intensity modulated radiotherapy) = allows a high dose of conformal RT to the target volume, while sparing surrounding normal tissues

Answer 24

rapid arc tx planning

Question 25

what % of RT is given with palliative intent

Answer 25

50%

Question 26

what is one of the only RT emergencies

Answer 26

spinal cord compression

Question 27

what is a CT simulation

Answer 27

a scan is taken of the area of the body to be treated, so that radiation can be planned

Question 28

what do you need when doing a CT simulation for brain/ head/ neck tumors

Answer 28

mask to keep head still

Question 29

planning of a CT scane is done by

Answer 29

radiation oncologist

Question 30

calculations and prep for CT are done by

Answer 30

radiation therapists and dosimetrists

Question 31

what is the only generalized SE of RT

Answer 31

fatigue

Question 32

what are some early SEs of RT - general - RT over abdominal/ pelvis - RT over chest

Answer 32

skin redness and irritation - RT over abdomen/ pelvis = nausea and diarrhea - RT over chest = esophagitis

Question 33

early SE of RT are usually 1. common but self limited 2. severe and permanent 3. severe and requires immediate attention 4. nonsevere and permanent

Answer 33

1. common but self limited

Question 34

late SE of RT are usually 1. common but self limited 2. uncommon and permanent 3. severe and requires immediate attention 4. nonsevere and permanent

Answer 34

2

Question 35

what is the criteria of diagnosing a secondary malignancy from RT

Answer 35

Within or at border of RT field Previously normal tissue Latent period exists (=>3yrs) Histologically proven different from primary cancer