W&L

Question 1

treatment with x-rays produced between 100-300 kV

Answer 1

orthovoltage

Question 2

types of tumor commonly treated with orthovoltage

Answer 2

skin, mouth, rectal carcinoa

Question 3

depth treated with an orthovoltage machine

Answer 3

2-3 cm

Question 4

most skin lesions treated with orthovoltage are

Answer 4

squamous cell and basal cell

Question 5

1—300 kv xray beam (orthovoltage) is more effective in treating superficial tumors like skin cancer because

Answer 5

it limits dose to normal tissue underneath

Question 6

xray beams of 1 MV or greater can be classified as

Answer 6

megavoltage

Question 7

example of a megavoltage machine

Answer 7

cobalt-60

Question 8

what does linear accelerator mean

Answer 8

charged particles travel in a straight line while they gain energy from an alternating electromagnetic field

Question 9

clystron

Answer 9

particles travel in a spiral pattern

Question 10

betatron

Answer 10

particles travel in a circular pattern

Question 11

accelerator structure

Answer 11

basic element of the linear accelerator

Question 12

accelerating waveguide

Answer 12

allows electrons produced from a hot cathode to gain energy until they exit the far end of the hollow structure

Question 13

bending magnet

Answer 13

used in high-energy linear accelerators to bend the electron stream at a variety of angles so that it is pointed at the target

Question 14

form of radiowave amplifier that greatly multiplies the amount of introduced radiowaves

Answer 14

klystron

Question 15

microwave frequency needed for linear accelerator operation are

Answer 15

approx. 3 billion cycles per second (300 MHz)^22

Question 16

major difference between magnetron and klytron

Answer 16

klystron is a linear-beam microwave amplifier requiring an external oscillator or radiofrequency source; the magnetron IS an oscillator and amplifier

Question 17

first linear accelerator was installed

Answer 17

1952 in Hammersmith Hospital in

London

Question 18

radiation may only be delivered under the direct supervision of a

Answer 18

radiation oncologist

Question 19

fractionisation

Answer 19

individual treatment dose

Question 20

protraction

Answer 20

time period in which the treatment will be given

Question 21

beam modifiers

Answer 21

devices that change the shape of the treatment field or distribution of the radiation at depth.

Question 22

point of intersection of three axes of machine rotation (gantry, collimator, and base of couch) and treatment target volumes must be identified

Answer 22

isocenter

Question 23

volume of tissue exposed to radiation from a single radiation beam

Answer 23

treatment field (also called a portal)

Question 24

total time during which treatment is protracted

Answer 24

elapsed days

Question 25

documentation of treatment through radiographic or electronic imaging devices

Answer 25

verification imaging

Question 26

colonization

Answer 26

involves the reproduction of an infectious microorganism that would result in a detectable immune response

Question 27

a person who colonizes but is not ill

Answer 27

carrier

Question 28

pathogenicity

Answer 28

ability of an infectious agent to cause clinical disease

Question 29

virulence

Answer 29

severity of a clinical disease and is typically expressed in terms of morbidity and mortality

Question 30

time interval between exposure and the appearance of the first symptom

Answer 30

incubation