ASRT SEAL Exam 6 - RTT KB

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.

Timing the radiation beam is on

Surface brachytherapy is MOST commonly used to treat ___________ skin cancer

Nonmelanoma skin cancer.

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?

L4.

At which vertebral bodies is the carina located?

T4-T5.

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

Photoelectric absorption.

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

that apply.

-type of source

-amount of radioactive material

Emergency off buttons, dose rate monitoring, use of coded wedge filters, and collision avoidance

systems are examples of:

Interlocks.

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

Compton scattering.

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

Decrease.

What does a tumor assigned a grade of G4 indicate?

Undifferentiated.

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 ________.

absorbed; photoelectric interaction.

_________ that give visible and audible warnings are required when the treatment is in progress and

when the treatment is terminated.

Beam-on indicators.

What diet is recommended for patients undergoing pelvic radiation?

Low fiber diet.

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

-Twice a day treatments (BID)

-three times a day treatments (TID).

Cell differentiation is referred to as:

Grade.

What is a measure of machine output from a linear accelerator defined as?

Monitor unit.

What are Cerrobend blocks made from?

Bismuth, lead, tin, and cadmium

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.

20%

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

include the:

control console

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

2 mm

Brachytherapy __________ categories are based on the relationship between the rate of tumor cell

proliferation and treatment duration.

dose rate

Which type of rays has the longest wavelength?

Microwaves

How can half value layer be calculated?

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

Hand washing

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

____________ brachytherapy.

pulsed-dose rate

What is a normal range for fasting blood sugar?

Less than 100 mg/dL

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

Myelosuppression

Tuberculosis is an example of an infection by which route?

Airborne

What is the most common metastatic site for prostate cancer?

Bone

What is the point of intersection of the gantry, collimator, and base of the couch called?

Isocenter

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

photon is the ________ interaction

Photoelectric interaction

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

Leaf transmission

How do you calculate the hinge angle between two fields with 30-degree wedges?

HA = 180 - 2(wedge angle), resulting in 120 degrees

How much cGy will the left lateral field contribute to the tumor if the total is 5,750 cGy with a 2:1 RT to LT weighting?

1,917 cGy

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

To block the exit beam and protect the nasal septum

What cycle does the chain of infection follow?

Host-infectious microorganism-reservoir-mode of transmission

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

dose will depend on:

The beam energy and the thickness of the mask

Patients taking metformin should stop taking the medication ______ hours before having contrast

administration for a CT simulation.

48 hours

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

Target

What is the anatomical landmark for the angle of the mandible?

C3

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

electron beams.

Thermoluminescent (TLD)

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

apply

-PDD decreases as the depth in tissue increases.

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

-PDD increases with an increase in beam energy

Verification of the correct treatment field placement to the treatment plan isocenter relative to patient

anatomy is BEST performed by using _________ images.

Beam's eye view

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

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

Which of these contrast reactions is considered minor?

Nausea

Which interactions result in the highest exposure to the patient?

Compton and photoelectric

A stage II skin reaction is depicted by:

dry desquamation

A patient suffering from hypoglycemia should be offered:

Orange juice sweetened with sugar

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

-instananeous response

-output constancy checks

-measurement of electron beams

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

to the whole body

450 mSv.

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?

44 cm x 44 cm.

-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

Which tumor originates from smooth muscle?

Leiomyosarcoma.

A mild allergic reaction can present with:

Itching and urticaria.

Which of these values is a normal adult creatinine level?

0.8 mg/dl.

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

At the T4 - T5 vertebra.

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?

91 cm on both sides.

Which component of the physical exam identifies pain in underlying tissue?

percussion

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

Daily.

Which tumor is more likely to be well differentiated?

Meningioma.

Which circulating blood cells are most resistant to radiation?

Platelets.

In 3D planning, evaluation of the doses that involve the organ at risk (OAR) and their localization within

the structures are BEST demonstrated by _____________.

Dose clouds.

A lifetime effective dose or cumulative effective dose limits a radiation worker's exposure limit to his/her

age multiplied by _________.

Their age multiplied by 10 mSv.

Which staging scenario is the most advanced?

T0N2M0.

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.

scattered; compton

______ 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.

Autofielding

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

50 mSv

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

Angstrom

What are conditions acquired in the hospital setting known as?

Nosocomial infections

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

Controlled area

What are the two groups of seizures?

Generalized seizures and focal seizures

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?

Fiducial

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

rectum

What type of infection is strep throat an example of?

Bacteria

What are two fields that are separated by 180 degrees called?

Parallel opposed beams

How often should collision interlocks of the onboard imagers be checked?

Daily

What photon interaction dominates at 50 MeV?

Pair production

Which of the following describe areas of the treatment room that directly interact with the useful beam,

and are required for proper shielding?

Primary barriers

Which malignancy is most likely to invade lymph nodes?

Squamous cell carcinoma

From what do seminomas of the testes arise?

Germ cells

Where are breast tumors most commonly located?

Upper outer quadrant

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

treatment _________.

Localization

Anaphylactic shock may occur during which of the following procedures?

contrast administration

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

-source to axis distance (SAD)

What type of cancer cell is most similar to the cell of origin?

Well differentiated

What do portal images verify?

-Beam shape and position

-projection of the beam's central axis

What is the monthly equivalent dose limit for pregnant radiation workers?

0.5 mSv

Where is the anatomical location of the hilum of the kidneys?

T12 - L2

What is NOT a purpose of cancer staging?

Determine the degree of cell differentiation

What is the equivalent square for a field of 10.2 x 10.2?

11.2 x 11.2

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

Heel

What is the range of electrons in water for a 12 MeV beam?

6 cm

Permanent alopecia is seen in radiation doses that reach ___ Gy

45 Gy

Intravenous contrast media can be toxic to the:

Kidneys

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

Nasopharynx

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?

2,400 cGy : 3,600 cGy

__________ 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.

Quantec

Which tumor arises from epithelium?

Adenocarcinoma

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

transmission?

Fomite

Radiation treatments are given in daily fractions, sometimes expanding over a period of 5 - 8 weeks.

What is this called?

Fractionation

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

± 2 mm