ASRT RRT (test 6, 5,7)

What photon interaction dominates at 50 MeV?

Photoelectric effect

Coherent scattering

Compton effect

Pair production

Pair production

*Photoelectric effect dominates at energies less than 25 KeV, most often used in diagnostic equipment.

*Compton effect dominates at energies between 25 KeV and 10 MeV, which encompasses any therapeutic radiation energies.

*Pair production effect dominates at 50 MeV

If a linear accelerator nominal target to skin distance (TSD) is 100 cm and the maximum field size dialed is a 40 cm x 40 cm field, what would the field size be at 110 cm TSD?

10 cm x 10 cm

40 cm x 40 cm

44 cm x 44 cm

110 cm x 110 cm

44 cm x 44 cm

Feedback Use the similar triangle philosophy or the following equation: a/b=a^'/b^' field_1/field_2 =TSD_1/TSD_2 40/x=100/110 40*110=100x 4400 =100x 4400/100=100x/100 44 = x

Silicon diodes are useful for which of the following? Please select all that apply.

personnel monitoring

measurement of electron beams

output constancy checks

Instananeous response

measurement of electron beams

output constancy checks

Instananeous response

Feedback Silicon diodes are useful due to their high sensitivity, instantaneous response, and small size. They are also used for patient dose monitoring.

Collision interlocks of the on board imagers should be checked.

Daily

Weekly

Monthly

Annually

Daily

Feedback Collision interlocks should be checked daily. The test is a pass/fail test. The interlocks are designed to protect the safety of the patient, staff and equipment.

The interaction between x-ray photons and tissue that results in the production of a secondary x-ray photon is the ________ interaction.

coherent

Compton

photoelectric

characteristic

Photoelectric

Feedback The photoelectric interaction results in the ejection of an inner shell electron. The loss of the inner shell electron creates an unstable atom that causes transition of an electron from another shell into the vacant shell. The movement of the electron from one shell to another produces a secondary x-ray photon.

The monthly equivalent dose limit for pregnant radiation workers should not exceed ________ per month.

0.1 mSv

0.5 mSv

1 mSv

5 mSv

0.5 mSv

Feedback The occupational dose limit for pregnant radiation workers is 0.5 mSv per month and not to exceed 5.0 mSv for the entire pregnancy.

Which of the following describe areas of the treatment room that directly interact with the useful beam, and are required for proper shielding?

Cerrobend blocks

Primary barriers

Secondary barriers

Constant monitoring

Primary barriers

Feedback Shielding by primary barriers is required for any wall intercepting the useful or primary beam. This includes the floor, ceiling, and side walls.

Intravenous contrast media can be toxic to the:

Heart

Arteries

Kidneys

Bladder

Kidneys

Feedback Blood work is required prior to contrast administration, as nephrotoxicity can result if the renal function is poor.

Breast tumors are most commonly located in the _____________quadrant.

Upper inner

Upper outer

Lower inner

Lower outer

Upper inner

Feedback The upper outer quadrant is the most common location, followed by central, upper inner, lower outer, and lower inner quadrants

The interaction that takes place between the incident x-ray photon and an inner shell electron is called:

classical scatter.

incoherent scatter.

photoelectric absorption.

photodisintegration.

Photoelectric absorption

Feedback The interaction between the incident x-ray photon and an inner shell electron is the photoelectric absorption.

Afterloading techniques _________ exposure to operating room personnel and radiation therapists.

increase

decrease

intensify

double

decrease

Feedback The use of afterloading techniques involve no exposure to operating room personnel or therapists.

A medical event, according to the Nuclear Regulatory Commission, is determined an event if the total dose delivered differs from the prescribed dose by __% or more.

10

15

20

25

20

Feedback A medical event occurs when the total dose delivered differs from the prescribed dose by 20% or more. If a medical event has occurred, the licensee in an NRC state must notify by telephone the NRC operations center no later than the next calendar day after the discovery of the medical event. In addition, a written report must be submitted to the NRC regional office within 15 days after the discovery of the medical event. The report must include the licensee's and prescribing physician's name, a description of the event, what effect occurred, why the event occurred and actions taken, and certification that the individual or relative was notified.

Which of the following circulating blood cells is MOST resistant to radiation?

Erythroblasts

Lymphocytes

Monocytes

Platelets

Platelets

Feedback Platelets are the most radioresistant in circulating blood as they can withstand greater than 50 cGy.

Surface brachytherapy is MOST commonly used to treat ___________ skin cancer.

melanoma

nonmelanoma

basal

squamous

Non melanoma

Feedback Nonmelanoma skin cancer can be treated using a custom mold of the body part prepared by placing sources in an arranged pattern to deliver the prescribed dose

A lifetime effective dose or cumulative effective dose limits a radiation worker's exposure limit to his/her age multiplied by _________.

1 mSv

5 mSv

10 mSv

50 mSv

10 mSv

Feedback The cumulative effective dose pertains to the whole body and includes external and internal exposure.

A patient suffering from hypoglycemia should be offered:

Orange juice sweetened with sugar.

A salad.

Coffee.

Water.

Orange juice sweetened with sugar.

Feedback Hypoglycemia refers to a condition caused by a very low blood sugar level. Hypoglycemia is often related to diabetes but there are other illnesses and conditions that can cause low blood sugar. Symptoms of low blood sugar include fatigue, pale skin, an irregular heart rhythm, shakiness, anxiety, sweating, hunger, irritability, tingling sensation around the mouth and crying out during sleep. Severe hypoglycemia symptoms include confusion, blurred vision, seizures, and loss of consciousness. A patient suffering from hypoglycemia should be given juice sweetened with sugar to raise their sugar level.

Conditions acquired in the hospital setting are known as:

Bacterial infections.

Isolation infections.

Medical infections.

Nosocomial infections

Nosocomial infections

Feedback Nosocomial infections refer to infections that have been caught by a patient in a hospital. According to the CDC, the most common pathogens that cause nosocomial infections are Staphylococcus aureus, Pseudomonas aeruginosa, and E. coli. Some of the common nosocomial infections are urinary tract infections, respiratory pneumonia, surgical site wound infections, bacteria, gastrointestinal and skin infections.

When the x-ray photon strikes an atom within the tissue being imaged and loses only part of its energy to an outer shell electron of that atom, the photon is said to have been ________ and undergone a(n) ________ interaction.

transmitted; coherent effect

absorbed; photoelectric

attenuated; pair production

scattered; Compton

scattered; Compton

The biologic effectiveness of low-dose rate treatments can be reproduced using remote afterloading with ____________ brachytherapy.

high dose rate (HDR)

medium dose rate

surface

pulsed-dose rate

pulsed-dose rate

Verification of the correct treatment field placement to the treatment plan isocenter relative to patient anatomy is BEST performed by using _________ images.

CT

MR

PET-CT

beam's eye view

beam's eye view

Which of the following statements about percentage depth dose (PDD) are correct? Please select all that apply.

PDD increases with an increase in beam energy

PDD decreases with an increase in field size

PDD increases with an increase in source to surface distance (SSD)

PDD decreases as the depth in tissue increases

-PDD increases with an increase in beam energy

-PDD increases with an increase in source to surface distance (SSD)

-PDD decreases as the depth in tissue increases

Feedback PDD increases with an increase in beam energy, field size, and SSD. PDD decreases as the depth in tissue increases.

Which of the following measurements are needed to aid you in checking the accuracy of the contour? Please select all that apply.

Patient AP and lateral measurements

Field size

source to axis distance (SAD)

percentage depth dose (PDD)

-Patient AP and lateral measurements

-source to axis distance (SAD)

Feedback In order to check the accuracy of a contour, the patients AP and lateral measurements as well as the SAD are needed.

The carina is located at the level of which vertebral bodies?

T1-T2

T2-T3

T3-T4

T4-T5

T4-T5

Emergency off buttons, dose rate monitoring, use of coded wedge filters, and collision avoidance systems are examples of:

Hazards

Monthly safety checks

Interlocks

Collimation systems

Interlocks

The _____ portion of the wedge allows for less transmission of photons.

Heel

Lateral

Middle

Toe

Heel

An example of an attenuation quality assurance test for MLC includes:

Leaf speed

Leaf transmission

Leaf position accuracy

Verification of MLC field

Leaf transmission

The MOST common metastatic site for prostate cancer is the:

Brain.

Bone.

Lung.

Liver.

Bone

Calculate the hinge angle between two fields if a patient is being treated with 30-degree wedges.

90

120

150

180

120

Cerrobend blocks are made using a combination of which of the following metals?

Iron, steel, tin, copper

Aluminum, lead, copper, tin

Bismuth, lead, tin, cadmium

Bronze, tin, lead, nickel

Bismuth, lead, tin, cadmium (BLT & C)

When simulating a patient with a glioblastoma (GBM), the patient is:

Supine with arms at side. A thermoplastic mask and IV contrast are used. Prone with hands by head. A thermoplastic mask and IV contrast are used. Supine with hands over head. Barium sulfate contrast is used.

Supine with arms akimbo. IV contrast is used.

Supine with arms at side. A thermoplastic mask and IV contrast are used.

MOST importantly, a patient being treated for Hodgkin's disease must be monitored for:

Myelosuppression.

Nausea and vomiting.

Weight loss.

Neural signs

Myelosuppression.

When checking the lasers used in radiation therapy, they must be accurate within:

1 mm

2 mm

3 mm

2%

2 mm

Image verification used to identify hidden anatomy relative to observable or surface landmarks reproduce treatment _________.

review

localization

communication

guidelines

localization

Two fields that are separated by 180 degrees are termed?

Parallel opposed beams

Tangents

Orthogonal beams

Laterals

Parallel opposed beams

What is the anatomical landmark for angle of the mandible?

C1

C3

C5

C7

C3

Which of the following does not take attenuation of a radiation beam into account?

Bolus

Cerrobend block

Compensator

Target

Targert

Which of the following tumors originates from smooth muscle?

Rhabdomyosarcoma

Neuroblastoma

Angiosarcoma

Leiomyosarcoma

Leiomyosarcoma

In 3D planning, evaluation of the doses that involve the organ at risk (OAR) and their localization within the structures are BEST demonstrated by _____________.

isodose lines

dose clouds

autofielding

autoblocking

dose clouds

The anatomical location of the hilum of the kidneys is located at:

T5 - T6

T12 - L2

L1 - L5

S1 - S3

T12 - L2

The point of intersection of the gantry, collimator, and base of the couch is the ___________.

treatment plan

isocenter

BEV

PTV

Isocenter

A supervised limited access radiation area such as the treatment room is a ___________ area.

patient

workload

controlled

uncontrolled

controlled

Mechanical tolerance for stereotactic radiation therapy treatment delivery should be within ________.

± 2 mm

± 3 mm

± 2 cm

± 3 cm

± 2 mm

Permanent alopecia is seen in radiation doses that reach ___ Gy

25

30

40

45

45 Gy. (4,500 cGy)

A ______ dosimeter response is almost independent of energy in the megavoltage range of photon and electron beams.

optical stimulated luminescence (OSL)

thermoluminescent (TLD)

pocket ionization

personnel digital ionization

thermoluminescent (TLD)

The range of electrons in water for a 12 MeV beam is:

3 cm

4 cm

6 cm

Infinite

6 cm

Radiation treatments are given in daily fractions, sometimes expanding over a period of 5 - 8 weeks. What is this called?

Hyperfractionation

Forward planning

Fractionation

Protraction

Fractionation

Strep throat is an example of infection by:

Virus

Bacteria

Fungus

Protozoa

Bacteria

A 45 year old radiation therapist should limit his/her cumulative effective dose to no more than ________ to the whole body.

10 mSv

100 mSv

250 mSv

450 mSv

450 mSv

(age x 10 mSv) or (age x 1 rem)

When treating a skin cancer of the nose, why would a lead piece be inserted into the nostril?

To provide backscatter to the entrance site

To block the exit beam and protect the nasal septum

To provide immobilization

To shield and shape the primary beam

To block the exit beam and protect the nasal septum

Patients taking metformin should stop taking the medication ______ hours before having contrast administration for a CT simulation.

12

24

36

48

48

Cell differentiation is referred to as:

Stage.

Histologic type.

Grade.

Sensitivity.

Grade

When treating pancreatic cancer, what target volume does not have to be routinely identified?

Kidneys

Liver

Rectum

Small Bowel

Rectum

A doctor indicates that the patient should be treated 2 cm superior to the bifurcation of the common iliac nodes, due to the patient's advanced bladder cancer. Where would the anatomical landmark for the bifurcation be found?

T6

L1

L4

S2

L4

A measure of machine output from a linear accelerator is defined as a:

monitor unit

minute of time

dose

energized unit

monitor unit

A cancer cell that is similar to the cell of origin is:

Well differentiated.

Moderately well differentiated.

Poorly differentiated.

Undifferentiated.

Well differentiated.

Seizures are separated into which two groups?

Generalized seizures and focal seizures

Acute and chronic

Short and long

Tonic and clonic

Generalized seizures and focal seizures

______ is a technique used to set an open area around the planning target volume (PTV), from the beam's eye view (BEV), to shape the field following contour of the PTV.

Normalization

Histogram

Autofielding

Autoblocking

Autofielding

Areas around the treatment are designated as controlled or uncontrolled. Areas designated as controlled include the:

Examination room.

Waiting room or lobby.

Control console.

Offices.

Control console.

Which component of the physical exam would most likely be able to identify pain in an underlying tissue?

Inspection

Palpation

Percussion

Auscultation

Percussion

What is the single most important means of preventing the spread of infection?

Using personal protective equipment

Wearing gloves

Coughing into shoulder

Hand washing

Hand washing

Which of these values is a normal adult creatinine level?

0.2 mg/dl

0.8 mg/dl

1.7 mg/dl

2.0 mg/dl

0.8 mg/dl

Which of the following malignancies is MOST likely to invade lymph nodes?

Chondrosarcoma

Squamous cell carcinoma

Liposarcoma

Ewing sarcoma

Squamous cell carcinoma

The chain of infection follows which cycle?

Reservoir-host-mode of transmission-infectious microorganism

Host-infectious microorganism-reservoir-mode of transmission

Host-reservoir-infectious microorganism-mode of transmission

Infectious microorganism-host-reservoir-mode of transmission

Host-infectious microorganism-reservoir-mode of transmission

A patient is being treated with isocentric parallel opposed lateral whole brain fields. The right lateral target to skin distance (TSD) is 92 cm and the left lateral TSD is 90 cm. If you need to treat to the field midline, what would the TSD read on the patients skin?

no change

90 cm on both sides

91 cm on both sides

100 cm on both sides

91 cm on both sides

________ scattering takes place at the level of an outer shell electron.

Unmodified

Compton

Coherent

Classical

Compton

Which of these tumors arises from epithelium?

Ewing sarcoma

Osteosarcoma

Hodgkin lymphoma

Adenocarcinoma

Adenocarcinoma

_________ summarizes the 3D doses given to the patient during their radiation treatment. It gives the physician the dose constraints needed for organs that are incorporated in the patient treatment plan.

Clarkson Method

Emami Tables

Quantec

WAN network

Quantec

Find the equivalent square for the following field.

10.2 x 10.2

11.2 x 11.2

12.2 x 12.2

13.2 x 13.2

11.2 x 11.2

The carina is generally located at which of the following vertebra?

C7

T5

T8

T12

T5

Which is NOT one of the purposes of cancer staging?

Determine the degree of cell differentiation

Define tumor size

Determine optimal treatment

Define degree of lymph node invasion

Determine the degree of cell differentiation

What is the term used for devices placed internally that are used to define a coordinate system in the treatment planning and delivery process which can be the basis to target the tumor by using an external 3D frame of reference?

Wedge

Stereotactic frame

Brachytherapy implant

Fiducial

Fiducial

Of the following staging scenarios, which is the most advanced?

T1N0M0

T0N1M0

T1N1M0

T0N2M0

T0N2M0

_______ interactions result in the highest exposure to the patient.

Compton and photoelectric

Photoelectric and coherent

Coherent and Compton

Compton and classical

Compton and photoelectric

Tuberculosis is an example of an infection by which route?

Contact

Droplet

Airborne

Blood borne

Airborne

What is a normal range for a fasting blood sugar?

less than 100 mg/dL

105-115 mg/dL

116-125 mg/dL

126 mg/dL or higher

less than 100 mg/dL

Which of the following has the longest wavelength?

UV rays

Visible rays

Microwaves

Gamma rays

Microwaves

A health care worker accidentally used contaminated gloves. The gloves are an example of which type of transmission?

Fomite

Vector

Host

Iatrogenic

Fomite

When the x-ray photon strikes an atom within the tissue being imaged and loses all its energy to an inner shell electron of that atom, the photon is said to have been ________ and undergone the ________.

transmitted; Compton effect

absorbed; photoelectric interaction

attenuated; Compton effect

scattered; coherent interaction

absorbed; photoelectric interaction

When using thermoplastic masks for immobilization, the patient skin dose must be considered. The skin dose will depend on:

The amount of water used to heat up the mask when constructing.

The beam energy and the thickness of the mask.

The beam energy only.

The thickness of the face mask only.

The beam energy and the thickness of the mask.

Gating techniques correspond to the _________________ with the desired target position as determined by the 4D fiducial software system used in this type of treatment delivery.

delivery of the radiation when the water flow to the machine is in line

organs at risk for treatment planning

time allotted for the patients scheduling

timing the radiation beam is on

timing the radiation beam is on

Portal images verify which of the following? Please select all that apply.

beam shape and position

projection of the beam's central axis

beam energy

tumor location

beam shape and position

projection of the beam's central axis

Feedback Portal images verify the beam's eye view, including the beam shape, position, and projection of the beams central axis.

The pharynx is divided into 3 sections. Which of the following sections is called the epipharynx?

Hypopharynx

Laryngeopharynx

Nasopharynx

Oropharynx

Nasopharynx

Of the following tumors, which is more likely to be well differentiated?

Squamous cell carcinoma of the cervix

Andenocarcinoma of the lung

Meningioma

Osteosarcoma

Meningioma

Brachytherapy __________ categories are based on the relationship between the rate of tumor cell proliferation and treatment duration.

half-life

substitute

dose rate

isotope

dose rate

The unit used to measure the wavelength associated with x-ray energy is the:

angstrom.

joule.

hertz.

electron volt

angstrom.

A head and neck patient is treated to midline (separation 14 cm, and .688 fractional depth dose (FDD)) with lateral fields to a total of 5,750 cGy with a 2:1 RT to LT weighting. The left lateral field will contribute _________ cGy to the tumor.

1,319

1,917

2,875

3,833

1,917

Seminoma of the testes arises from:

Sweat glands.

Nerve cells.

Germ cells.

Fibrous tissue.

Germ cells.

_______ that give visible and audible warnings are required when the treatment is in progress and when the treatment is terminated.

beam-on indicators

limitation devices

backup timer

personnel digital ionization

beam-on indicators

A mild allergic reaction can present with:

itching and urticaria

laryngeal tightening

shock

cardiac arrest

itching and urticaria

Anaphylactic shock may occur during which of the following procedures?

immobilization device creation

tattoo skin marking

contrast administration

brachytherapy

contrast administration

Which of the following is recommended for patients undergoing pelvic radiation?

Low protein diet

High fat diet

High fiber diet

Low fiber diet

Low fiber diet

The amount of shielding for brachytherapy sources depends on which of the following? Please select all that apply.

weight of source

density of source

type of source

amount of radioactive material

type of source

amount of radioactive material

Feedback The thickness of protective shielding required for brachytherapy sources depends on the type and amount of the radioactive material.

Which of these contrast reactions is considered minor?

Dyspnea

Nausea

Syncope

Cardiac arrhythmia

Nausea

CT number for accuracy with water is checked on a _____ basis in a CT simulator.

Daily

Weekly

Monthly

Annually

Daily

Examples of hyperfractionation include which of the following treatments? Please select all that apply.

once a day treatments

twice a day treatments (BID)

three times a day treatments (TID)

once every other day treatments

twice a day treatments (BID)

three times a day treatments (TID)

Feedback Hyperfactionated schedules replaced the older single, high-dose radiation treatment.

The annual occupational effective dose limits recommended by NCRP is ________.

5 mSv

50 mSv

5 Sv

50 Sv

50 mSv

A patient is being treated for a primary glioma of the brain. The prescription reads a total dose of 6,000 cGy to be delivered, but the gross tumor volume (GTV) is on the left side of the brain. The written directive says to use weighted lateral fields. Right : Left 2 : 3. What total dose will each field receive?

2,000 cGy : 4,000 cGy

3,000 cGy : 3,000 cGy

1,200 cGy : 4,800 cGy

2,400 cGy : 3,600 cGy

2,400 cGy : 3,600 cGy. (24Gy - 36Gy)

Half value layer can be calculated with which of the following equations?

I1/I2 = (d2/d1)2

0.693/

A0e-t

ln2/

0.693/

A tumor assigned a grade of G4 indicates the tumor is:

Well differentiated

Moderately differentiated

Poorly differentiated

Undifferentiated

Undifferentiated

A stage II skin reaction is depicted by:

Erythema

Moist desquamation

Dry desquamation

Necrosis

Dry desquamation