Nappi - Radiation Safety

Scattering foils are primary used in which energy range?

A) 4 MV

B) 6 MV

C) 10 MV

D) 12 MeV

D) 12 MeV

Which photon beam energy has the highest HVL for the same absorber material?

A) 250 kV

B) 1.25 MV

C) 511 kV

D) 6 MV

D) 6 MV

The probability of bremsstrahlung production:

A) Decreases with atomic number

B) Increases with atomic number

C) Is independent of atomic number

D) Decreases with the square of the atomic number

B) Increases with atomic number

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

A) 1%

B) 2%

C) 3%

D) 5%

C) 3%

Which of the following photon beam energies have the most desirable skin sparing effect?

A) 4 MV

B) 6 MV

C) 25 MV

D) 150 kV

C) 25 MV

Which of the following would not be used in room shielding calculations?

A) Beam energy

B) Use factor

C) Inverse square law

D) Scatter-air ratio

D) Scatter-air ratio

A Sievert (Sv) is a unit used to measure which of the following, and how does it relate to the biological effects of radiation?

A) Radiation exposure, as it quantifies the amount of ionizing radiation absorbed by a material

B) Dose equivalent, considering both the energy deposited and the biological impact of different radiation types

C) Dose rate, assessing the amount of radiation delivered over a specific time period

D) Air kerma, measuring the kinetic energy released per unit mass of air

B) Dose equivalent, considering both the energy deposited and the biological impact of different radiation types

Which of the following can be used as a tissue compensator? (Choose all that apply)

A) Shaped bolus

B) Wedge

C) Cerrobend

D) Dynamic MLC

A), B), C), & D) Shaped bolus, wedge, cerrobend, & dynamic MLC

Which of the following should be checked on a linac daily?

A) Light/radiation field coincidence

B) Beam flatness and symmetry

C) Field size indicators

D) None of the above

D) None of the above

Which of the following basic methods of protection is the most efficient way to increase protection from radiation?

A) Time

B) Distance

C) Shielding

D) Beam energy reduction

B) Distance

When calculating room shielding, what factor is defined by "the amount of time an adjacent room will be occupied"?

A) Acceptable weekly dose (P)

B) Workload (W)

C) Barrier (U)

D) Occupancy (T)

D) Occupancy (T)

The radiation therapist control room is considered a(n) ____ area. (Choose all that apply)

A) Restricted

B) Unrestricted

C) Controlled

D) Uncontrolled

A) & C) Restricted & controlled

All of the following are components of Cerrobend except:

A) Lead

B) Bismuth

C) Tin

D) Copper

D) Copper

Employees must be monitored for radiation exposure when they are expected to receive more than ____ of the effective dose equivalent.

A) 5%

B) 10%

C) 15%

D) 20%

B) 10%

The HU for fat is:

A) -1000

B) -100

C) 100

D) 1000

B) -100

The spectrum of different shades of gray or contrast on a CT image is:

A) Window level

B) Window width

C) Contrast resolution

D) Penumbra

B) Window width

The average or median of all the shades of gray on a CT image is:

A) Window level

B) Window width

C) Contrast resolution

D) Penumbra

A) Window level

The tolerance for gantry rotation check is:

A) 1 degree

B) 1 percent

C) 3 degrees

D) 3 percent

A) 1 degree

Atoms with the same number of protons but different number of neutrons are called:

A) Isotope

B) Isobar

C) Isotone

D) Isomer

A) Isotope

Atoms with the same number of neutrons but different number of protons are called:

A) Isotope

B) Isobar

C) Isotone

D) Isomer

C) Isotone

The brachytherapy application method in which the radioactive source is placed within a body tube is:

A) Intracavitary

B) Interluminal

C) Interstitial

D) Intervascular

B) Intraluminal

Which radioactive source has the shortest half-life?

A) Radium

B) Cobalt

C) Strontium

D) Yttrium

D) Yttrium

The power source for the waveguide is:

A) Magnetron

B) Circulator

C) Modulator

D) Klystron

C) Modulator

The part of the linear accelerator that amplifies microwaves is:

A) Magnetron

B) Circulator

C) Modulator

D) Klystron

D) Klystron

In a linear accelerator, what component serves as the primary source of electrons?

A) Magnetron

B) Modulator

C) Electron gun

D) Klystron

C) Electron gun

If the planned distance is 100 cm but the ODI on the patient reads 101.5 cm, what is the error?

A) An overdose of 3%

B) An underdose of 3%

C) An overdose of 1.5%

D) An underdose of 1.5%

B) An underdose of 3%

[(Planned/actual)^2] x 100 = % of planned dose received —> if under 100, subtract from 100 to get underdose %; if over 100, subtract 100 from answer to get overdose %

In the electromagnetic spectrum, frequency is inversely related to:

A) Wavelength

B) Photon energy

C) Velocity

D) Intensity

A) Wavelength

Exposure is 400 mR at 90 cm. What will the exposure be at 180 cm?

A) 50 mR

B) 100 mR

C) 150 mR

D) 200 mR

B) 100 mR

Among the following types of radiation, which exhibits the highest quality factor, reflecting its potential for biological damage per unit of absorbed dose?

A) X-rays

B) Alpha particles

C) Gamma rays

D) Neutrons

B) Alpha particles

The mAs setting primarily affects which of the following in relation to patient exposure?

A) The level of image contrast

B) The spatial resolution of the image

C) The radiation dose received by the patient

D) The size of the radiation field

C) The radiation dose received by the patient

Which of the following best describes the tolerances for safety interlocks, and why are these tolerances critical for maintaining safety?

A) Safety interlocks must ensure beam termination within 2% deviation from planned dose, to prevent overdose

B) Emergency stop buttons must enable beam output immediately upon activation, with verification performed during monthly QA

C) Door interlock systems must prevent beam activation when the treatment room door is open, with functional tolerances

C) Door interlock systems must prevent beam activation when the treatment room door is open, with functional tolerances

How many HVLs are needed to reduce the beam to 6.25% of its original value?

A) 3

B) 4

C) 5

D) 6

B) 4

The most radiosensitive part of a cell is:

A) RNA

B) DNA

C) Water

D) Mitochondria

B) DNA

OER in human cells is:

A) 1-1.5

B) 1.5-2

C) 2.5-3

D) 3.5-4

C) 2.5-3

Under established QA protocols, at what minimum frequency must safety indicator lights - such as treatment 'beam on' lights and warning signals - be tested?

A) Daily

B) Weekly

C) Monthly

D) Annually

A) Daily

The point on a dose-response relationship graph that represents the cells' capability to repair:

A) D0

B) Dq

C) n

D) D37

B) Dq

The point on a dose-response relationship graph that shows the cells' radiosensitivity:

A) D0

B) Dq

C) n

D) D73

A) D0

An example of a stochastic effect:

A) Erythema

B) Cataracts

C) Cancer

D) Epilation

C) Cancer

In the context of radiobiology, a "direct effect" occurs when ionizing radiation interacts with which critical cellular target?

A) DNA

B) RNA

C) Water

D) Blood brain barrier

A) DNA

Which SI unit is used to express the equivalent dose - factoring in both the absorbed energy and the biological effectiveness of the radiation - to reflect the potential harm to human tissue?

A) Gray

B) rad

C) Sievert

D) rem

C) Sievert

Which type of radiation survey instrument is commonly used to rapidly locate a missing radioactive source?

A) Geiger-Müller counter

B) Thermoluminescent dosimeter

C) Diode

D) Thimble chamber

A) Geiger-Müller counter

Which radiation instrument is used to measure the production of radiation in a linear accelerator?

A) Geiger-Müller counter

B) Thermoluminescent dosimeter

C) Cutie pie

D) Ion chamber

D) Ion chamber

In radiation dosimetry, which device detects absorbed ionizing radiation by releasing stored energy s visible light upon controlled heating, thereby providing a quantitative measure of the accumulated dose?

A) Geiger-Müller counter

B) OSL

C) TLD

D) Farmer chamber

C) TLD

Which radiation instrument is used to check the linac beam output daily?

A) Geiger-Müller counter

B) Diode

C) Cutie pie

D) Ion chamber

B) Diode

Which radiation instrument is used to calibrate ion chambers in a linac?

A) Thimble chamber

B) Diode

C) Cutie pie

D) Ion chamber

A) Thimble chamber

In a linac designed to produce multiple photon energies, which of the following best describes the beam flattening filters?

A) A single, universal beam flattening filter is used for all photon energies

B) Distinct, energy-specific flattening filters are used to achieve uniform dose distributions at each photon energy

C) Beam flattening filters are only used for electron beams and remain constant regardless of energy

D) Multiple filters are combined to flatten the beam for all photon energies

B) Distinct, energy-specific flattening filters are used to achieve uniform dose distributions at each photon energy

When differentiating gamma rays from x-rays, which are the primary differences between the two?

A) Gamma rays originate from the nucleus of radioactive atoms, while x-rays are produced by interactions of high-speed electrons with target materials or orbital electrons

B) Gamma rays are always higher in energy than x-rays

C) Gamma rays travel faster than x-rays through any medium

D) Gamma rays differ from x-rays because they have. variable speed depending on their energy level

A) Gamma rays originate from the nucleus of radioactive atoms, while x-rays are produced by interactions of high-speed electrons with target materials or orbital electrons

Atoms that have the same number of protons, but differ in the number of neutrons are referred to as a(n):

A) Isomer

B) Isotone

C) Isobar

D) Isotope

D) Isotope

Beyond which atomic (Z) number do elements generally exhibit increasing instability and become predominantly radioactive?

A) 74

B) 82

C) 99

D) 120

B) 82

Which of the following radiation areas is typically accessible only to authorized personnel with specific training? (Choose all that apply)

A) Restricted area

B) Unrestricted area

C) Controlled area

D) Exclusion area

A) & C) Restricted & controlled area

What fundamental role dose the beam flattening filter serve in shaping the photon beam?

A) Produce a uniform photon beam

B) Generate an electron beam

C) Generate photons via Bremsstrahlung effect

D) Absorb unwanted low energy x-rays

A) Produce a uniform photon beam

Radioactivity emits all of the following except:

A) Alpha particles

B) Beta particles

C) Photons

D) Gamma rays

C) Photons

Tandem and ovoid applicators are which type of implantation technique, and what distinguishes this method in terms of source placement?

A) Interstitial brachytherapy, involving radioactive sources placed directly into the tumor tissue

B) Intracavitary brachytherapy, using applicators positioned within a natural body cavity

C) Intraluminal brachytherapy, placing sources along the inner surface of a hollow organ

D) Surface mold brachytherapy, applying sources over the external surface of the body

B) Intracavitary brachytherapy, using applicators positioned within a natural body cavity

In modern brachytherapy, a remote afterloader can be used to position a radioactive source embedded in a flexible nylon ribbon for target dose delivery. Which radionuclide is commonly employed in this configuration?

A) Iridium-192

B) Cobalt-60

C) Cesium-137

D) Iodine-125

A) Iridium-192

Which of the following statements about radiation exposure is true?

A) It decreases with decreasing distance from the radiation source

B) It has no health effects

C) It is not influenced by the type of radiation

D) It is cumulative over a person's lifetime

D) It is cumulative over a person's lifetime

Which of the following statements about the ALARA principle is true?

A) It stands for "Average Limit of Acceptable Radiation Amounts"

B) It promotes the use of the highest possible radiation doses for IGRT

C) It emphasizes the need for radiation doses to be "As Low As Reasonably Achievable"

D) It only applies to radiation therapy procedures

C) It emphasizes the need for radiation doses to be "As Low As Reasonably Achievable"

What parameter is typically evaluated during the picket fence QA test?

A) Leaf positioning accuracy

B) Treatment time accuracy

C) Beam energy stability

D) Dose rate uniformity

A) Leaf positioning accuracy

The primary purpose of using a collimator during imaging is to:

A) Increase the radiation dose to the patient

B) Improve image contrast

C) Reduce patient motion blue

D) Limit the size and shape of the x-ray beam

D) Limit the size and shape of the x-ray beam

Which exposure factor primarily controls the quality or penetrating power of the x-ray beam in the diagnostic range?

A) kVp

B) mAs

C) SSD

D) Magnification factor

A) kVp

When doubling the mAs, the resulting x-ray beam will have:

A) Four times the exposure

B) Half the exposure

C) Double the exposure

D) One-fourth the exposure

C) Double the exposure

Which of the following examples requires a secondary radiation barrier? (Choose all that apply)

A) Primary electron beam

B) Primary photon beam

C) Scatter radiation

D) Leakage radiation

C) & D) Scatter & leakage radiation

What is the primary purpose of radiation shielding in a linear accelerator vault?

A) To protect the linear accelerator from external interference

B) To regulate the temperature inside the vault

C) To minimize radiation exposure to patients and staff

D) To ensure proper airflow for equipment cooling

C) To minimize radiation exposure to patients and staff

Which material is commonly used for radiation shielding for a linear accelerator vault?

A) Concrete

B) Aluminum

C) Cerrobend

D) Steel

A) Concrete

Where should the radiation shielding be placed in a linear accelerator vault?

A) On the walls and ceiling

B) On the floor and walls

C) On the ceiling and floor

D) On the walls, ceiling, and floor

D) On the walls, ceiling, and floor

What is the purpose of safety lights in a linear accelerator room?

A) To provide ambient lighting during treatment

B) To indicate when the accelerator is operational

C) To signal potential hazards or unsafe conditions

D) To signal when treatment is completed

B) To indicate when the accelerator is operational

What is the purpose of the MLC in the linac?

A) To shape and conform the electron beam

B) To reduce leakage radiation

C) To shape and conform the photon beam

D) To shape and conform the kV imaging field

C) To shape and conform the photon beam

What is the tolerance for localizing lasers for SRS/SBRT machines?

A) 1 mm

B) 1.5 mm

C) 2 mm

D) 1 cm

A) 1 mm

What is the purpose of using a maze in a treatment vault?

A) To enhance treatment accuracy

B) To confine the beam to a point source

C) To reduce radiation scatter reaching the door

D) To eliminate the need for primary barriers

C) To reduce radiation scatter reaching the door

How does increasing the distance from a radiation source affect radiation exposure?

A) It increases radiation exposure

B) It has no impact on radiation exposure

C) It decreases radiation exposure

D) It alters the type of radiation being emitted

C) It decreases radiation exposure

Which of the following is a natural source of radiation exposure?

A) Medical imaging

B) Nuclear power plants

C) Consumer products

D) Radon gas

D) Radon gas

Which of the following is an important safety feature in a linac vault?

A) Large windows for air flow

B) Emergency stop buttons at multiple locations

C) Open access to treatment planning computers

D) Unrestricted access to the vault for patients and visitors

B) Emergency stop buttons at multiple locations

What is the primary source of background radiation?

A) Man-made sources such as medical imaging and nuclear power generation

B) Radon gas released from the decay of uranium in soil and rock

C) Cosmic radiation originating from deep space and the sun

D) Residual fallout from historical nuclear weapons testing

B) Radon gas released from the decay of uranium in soil and rock

What is the purpose of performing a star pattern test?

A) To evaluate the overall performance of the linear accelerator

B) To assess the accuracy and precision of gantry and collimator rotation

C) To measure the radiation output of the gantry and collimator

D) To monitor the treatment time during radiation delivery

B) To assess the accuracy and precision of gantry and collimator rotation

What type of radiation dose is typically monitored using personnel dosimeters?

A) Equivalent dose

B) Effective dose

C) Integral dose

D) Absorbed dose

A) Equivalent dose

Which of the following is not a recommended type of personnel dosimeter?

A) Film badges

B) Optically stimulated luminescence (OSL) dosimeters

C) Thermoluminescent dosimeters (TLDs)

D) Geiger-Müller counters

D) Geiger-Müller counters

Which component of a CT simulator converts x-rays into electrical signals?

A) Cathode

B) Anode

C) High voltage generator

D) Detector array

D) Detector array

What action should be taken if a personnel dosimeter indicates an unexpectedly high radiation dose?

A) The dosimeter should be recalibrated immediately

B) The individual should stop working with radiation until the cause is investigated

C) The dosimeter should be discarded and a new one issued

D) The dose should be considered invalid and disregarded

B) The individual should stop working with radiation until the cause is investigated

Who is responsible for reviewing and maintaining personnel dosimetry records?

A) The radiation safety officer

B) The radiation oncologist

C) The medical physicist

D) The radiation therapist

A) The radiation safety officer

What type of radiation area has radiation levels that are expected to be within regulatory limits and poses minimal risk to individuals?

A) Restricted area

B) Controlled area

C) Unrestricted area

D) Exclusion area

C) Unrestricted area

Why is magnetic field screening necessary before entering an MRI room?

A) To ensure proper functioning of the MRI machine

B) To protect individuals from potential biological effects of the magnetic field

C) To prevent interference with electronic devices

D) To minimize the risk of allergic reactions to contrast agents

B) To protect individuals from potential biological effects of the magnetic field

Which component of the CT simulator allows for marking of the isocenter and/or treatment field?

A) Movable lasers

B) Detector array

C) MLC

D) Optical tracking systems

A) Movable lasers

What is the purpose of the safety questionnaire during magnetic field screening?

A) To assess an individual's knowledge of MRI technology

B) To determine the individual's eligibility for an MRI examination

C) To identify any potential safety concerns or contraindications

D) To evaluate the individual's previous exposure to radiation

C) To identify any potential safety concerns or contraindications

What is the purpose of marking MRI-compatible equipment with specific labels or symbols?

A) To indicate the manufacturer of the equipment

B) To ensure proper handling and storage of the equipment

C) To track the maintenance history of the equipment

D) To identify equipment that is safe for use in the MRI environment

D) To identify equipment that is safe for use in the MRI environment

Which of the following is not a recommended practice for storing radioactive materials?

A) Keeping them in locked and labeled containers

B) Placing them in an open area for easy access

C) Storing them separately from non-radioactive materials

D) Ensuring proper shielding of the containers

B) Placing them in an open area for easy access

What is the equivalent of 1 Gray in Seiverts?

A) 1 Sv

B) 0.1 Sv

C) 10 Sv

D) 100 Sv

A) 1 Sv

Which component in a linac generates the high-energy electron beam used to create either a photon or electron beam?

A) Waveguide

B) Magnetron

C) Electron gun

D) Klystron

C) Electron gun

What is the purpose of the bending magnet or steering magnets in a linac?

A) To generate the electron beam

B) To collimate the photon beam

C) To create Bremsstrahlung radiation

D) To confine the electron beam

D) To confine the electron beam

How can the results of a picket fence QA test be used to improve MLC performance?

A) By adjusting the treatment time during MLC delivery

B) By identifying and correcting any MLC leaf positioning errors

C) By calibrating the radiation output of the MLC

D) By optimizing the treatment plan's isodose distribution

B) By identifying and correcting any MLC leaf positioning errors

10 Sieverts is equivalent to how many rem?

A) 0.1 rem

B) 1 rem

C) 100 rem

D) 1000 rem

D) 1000 rem

What is the tolerance for localizing lasers for non-IMRT machines?

A) 1 mm

B) 1.5 mm

C) 2 mm

D) 1 cm

C) 2 mm

What is the primary component responsible for producing x-rays in the CT Sim machine?

A) X-ray tube

B) Detector array

C) High voltage generator

D) Cooling system

A) X-ray tube

What is the purpose of the interlock system in a linear accelerator?

A) To ensure patient comfort during treatment

B) To monitor the treatment time

C) To prevent unsafe conditions and ensure patient and staff safety

D) To calibrate the radiation dose delivery

C) To prevent unsafe conditions and ensure patient and staff safety

How often should emergency switches be checked?

A) Daily

B) Weekly

C) Monthly

D) Annually

C) Monthly

1 rad is equivalent to how many Gray?

A) 0.01 Gy

B) 0.1 Gy

C) 10 Gy

D) 100 Gy

A) 0.01 Gy