Definitions

Question 1

Percent depth dose

Answer 1

the ratio of dose at depth in tissue to the dose at electronic equilibrium on the beam axis. The ratio of dose at Dmax to dose at a certain depth in tissue.

Question 2

Hypertension

Answer 2

a dizzy feeling associated with sitting or standing after a prolonged period of bed rest

Question 3

Usage factor

Answer 3

the fraction of TIME in a treatment day in which a beam will be pointed at a particular barrier

Question 4

Workload

Answer 4

the OUTPUT of the linac in a day

Question 5

Occupancy factor

Answer 5

the fraction of time in a day a person will be OCCUPYING a space behind a particular barrier

Question 6

Dose profile

Answer 6

a representation of the dose in an irradiated volume, as a function of spatial position along a single line

Question 7

Linear attenuation coefficient (u)

Answer 7

fraction of photons attenuated per unit thickness

Question 8

The shape of the isodose curves depends largely on two things:

Answer 8

field size and flattening filters

Question 9

Irradiated volume

Answer 9

the volume larger than the treatment volume receiving some significant dose

Question 10

Tumor volume

Answer 10

the actual physical dimensions of the tumor, including regions of presumed occult spread

Question 11

As SSD increases, the depth dose….

Answer 11

increases

Question 12

Exposure is measured in

Answer 12

C/ kg

Question 13

Rad is measured in

Answer 13

J/ kg

Question 14

Stopping power

Answer 14

the rate of kinetic energy lost per unit path length

Question 15

Compton interaction is independent from…..

Answer 15

atomic number. Only photon and free electron

Question 16

Pair production is ____ photon interaction with the nucleus.

Answer 16

direct

Question 17

Isodose curve

Answer 17

points within the patient receiving the same dose are joined together forming a curve

Question 18

What is the tolerance for daily check of linac output consistency?

Answer 18

3%

Question 19

Pancytopenia

Answer 19

side effect from chemo that decreases in many cellular components of the blood

Question 20

Ovarian cancer signs are (3):

Answer 20

abdominal bloating, nausea, constipation. NOT VAGINAL BLEEDING

Question 21

• Early stage ovarian is treated with:

- Late stage ovarian is treated with:

Answer 21

• Surgery and then chemo

- EBRT

Question 22

Early endometrial cancer sign is

Answer 22

abnormal vaginal bleeding

Question 23

Cisplatin can cause what loss?

Answer 23

Hearing

Question 24

Half-value thickness

Answer 24

is the thickness of material that reduces beam intensity to half its original value

Question 25

What factor controls the contrast of an image?

Answer 25

Window width

Question 26

What factor controls the brightness of an image?

Answer 26

window level

Question 27

Linear Energy Transfer

Answer 27

rate that energy is deposited as it travels through matter

Question 28

- What is Oxygen Enhancement Ratio? | - What is the formula?

Answer 28

- compares the response of the cells to radiation with and without the presence of oxygen - Anoxic/ oxic