Exam 2 Linear Acceleration

Question 1

The modulator cabinet consists of all of the following, except:

Answer 1

Water Cooling System

Question 2

A cyclotron accelerates charged particles outwards from the center of a flat cylindrical vacuum chamber in a _________ pattern

Answer 2

Spiral

Question 3

Electron gun function

Answer 3

produces electrons and injects them into the accelerator structure

Question 4

Cathode

Answer 4

Spherically shaped structure made of a material with a high atomic number

Question 5

Accelerator Structure (guide) function

Answer 5

accelerates electrons through multiple cavities in a linear fashion

Question 6

Treatment Head

Answer 6

Comprised of several components designed to monitor and shape the treatment beam

Question 7

Bending Magnet

Answer 7

Magnet system that focuses and directs the electron beam from the accelerating structure toward the treatment head

Question 8

X-ray Target

Answer 8

placed in a electron beam to create a x-ray beam

Question 9

Primary Collimators function

Answer 9

Shapes the beam, sets maximum field size of the beam at iso center

Question 10

Beam-flattening filter

Answer 10

Flattens the x-ray beam exiting the target

Question 11

Scattering Foil

Answer 11

Scatter electrons to create uniform beam of electrons for treatment

Question 12

Ion Chamber measures (3)

Answer 12

1. Dose
2. Flatness
3. Symmetry

Question 13

Secondary collimators

Answer 13

Jaws of the machine, sets field size of the beam, often asymmetric

Question 14

A Klystron amplifies __________ (supplied by radiofrequency driver) in machines >10 MV

Answer 14

microwaves

Question 15

Arc (or Rotational Therapy)

Answer 15

radiation is delivered while the gantry moves in a arc from one point to another

Question 16

Stereotactic Radiosurgery

Answer 16

high-dose radiation therapy in a single dose, usually cranial tumors

Question 17

Stereotactic Body Radiation Therapy

Answer 17

high-dose radiation therapy in fractionated doses, usually outside the cranium tumors

Question 18

Field in Field

Answer 18

technique employs small fields, often only a few centimeters in diameter with small numbers of monitor units, frequently as few as five; alternative to the use of wedged fields

Question 19

Simultaneous Integrated Boost (SIB)

Answer 19

a differential dose per fraction is delivered to selected sub-regions during the same treatment session, leading to different total nominal doses given to target volumes in the same number of fractions

Question 20

Intensity Modulated Radiation Therapy (IMRT)

Answer 20

advanced version of 3-D planning creating a nonuniform radiation beam allowing a better dose to the tumor while sparing more organs at risk (OAR)/normal tissue

Question 21

Step and Shoot (Static IMRT)

Answer 21

the beam is delivered with MLC’s in a stationary position, turned off as the MLC’s move to the next segment, and then turned back on

Question 22

Sliding Window (Dynamic IMRT)

Answer 22

the beam remains on as the MLC’s & gantry move throughout the treatment

Question 23

Volumetric modulated arc therapy (VMAT)

Answer 23

the beam is continuously delivered while the gantry & MLC’s are both in motion

Question 24

A Tomotherapy unit would best be classified as ___ delivery treatment machnie

Answer 24

Hellical

Question 25

Which of the following kV x-ray machines would be used to treat a skin cancer less than 1.5 cm thick?

Answer 25

Orthovoltage

Question 26

Linear accelerators have their roots in which of the following countries: (2)

Answer 26

1. USA 2. England

Question 27

The drive stand contains all of the following except:

Answer 27

Electron Gun

Question 28

Treatment couches in the treatment room are typically made of:

Answer 28

Carbon Fiber

Question 29

The treatment console is typically located inside the linac treatment room with a lead glass barrier. (T/F)

Answer 29

F

Question 30

Magnetron is a source of microwave power in machines ___(Power)____.

Answer 30

< or = 10 MV

Question 31

_______________ allow(s) many components in the gantry and drive stand to operate at a constant temperature.

Answer 31

Water Cooling System

Question 32

A Superficial unit produces x-rays ranging from __ - __ kV

Answer 32

40 -150 kV

Question 33

The treatment blocks are created in the ____________.

Answer 33

CT scanner

Question 34

The dome (top) of the diaphragm is considered to be at __(T#)___.

Answer 34

T9

Question 35

The iliac crest are located at __(L#)___.

Answer 35

L4

Question 36

A typical head and neck setup is as follows: (5)

Answer 36

1. S-board 2. Long mask 3. Clr C 4. Arms at side 5. Knee wedge

Question 37

The tip of the xiphoid process is at the ___T#___ vertebral level.

Answer 37

T10

Question 38

Tangents are typically used to treat breast cancer. (T/F)

Answer 38

T

Question 39

The disadvantages of 2D therapy are: (3)

Answer 39

1. Blocking is time consuming 2. More side effects 3. Large treatment fields

Question 40

The hyoid bone is at the level of ___c#____.

Answer 40

C4

Question 41

The thyroid and cricoid cartilage are at the level of __C#s____.

Answer 41

C5 - C6

Question 42

Obliques include all of the following except:

Answer 42

PA