ASRT SEAL 3

Question 1

When interacting with mature adults over the age of 65, radiation therapists should remember:

Most of these individuals are senile.
These mature adults consider themselves at a disadvantage because of their age.
These mature adults consider themselves middle aged.
These mature adults are less educated and less health savvy than those under the age of 65.

Answer 1

These mature adults consider themselves middle aged.

Question 2

When treating a craniospinal field, the PA spine target needs to be split into two fields. Field A has a field length of 14 cm and Field B has a field length of 32 cm. The beams will match at a depth of 5 cm. Both fields are treated at 100 cm source to surface distance (SSD). Calculate the skin gap needed to ensure the fields match at 5 cm.

1. 07 cm
2. 15 cm
3. 42 cm
4. 61 cm

Answer 2

1.15 cm

Question 3

Which of the following are recommended skin care practices for patients undergoing radiation therapy to the head and neck? Please select all that apply.

Covering skin to protect from sunlight.
Use of a loofa sponge.
Application of water based lotion and creams.
If a patient needs to shave, electric razors are preferred.

Answer 3

Covering skin to protect from sunlight.
Application of water based lotion and creams.
If a patient needs to shave, electric razors are preferred.

Question 4

Which treatment delivery method spares healthy tissue the LEAST?

IMRT
2D
VMAT
SBRT

Answer 4

2D

Question 5

What size will a 6 cm tumor be on an image if the isocenter is set in the tumor and the imager is at 140 cm, provided the machine isocenter distance is 100 cm?

4. 3 cm
5. 7 cm
6. 4 cm
7. 2 cm

Answer 5

8.4 cm

Similar triangles can be used to determine the size of a tumor or other object on an image. To determine the size of an object on an image at a specific target-to-image distance, you can use the similar triangle formula: a/a’= b/b’. You can also find the magnification factor (imager distance/object distance) and multiply the magnification factor by the object size (in this case the tumor).

Question 6

To ensure patient safety, the NCRP requires testing of the interlocks system at least once per:

Day.
Week.
Month.
Year.

Answer 6

Day

Question 7

Chemotherapy is administered concurrently with radiation therapy in the treatment of:

Breast carcinoma.
Hodgkin lymphoma.
Lung carcinoma.
Vocal cord carcinoma.

Answer 7

Lung carcinoma.

The standard of care in the treatment of lung cancer is concurrent chemotherapy with radiation therapy. Breast cancer is typically surgically excised, followed by chemotherapy (if necessary), then radiation therapy. Lymphomas are generally treated with chemotherapy first, and carcinomas limited to the vocal cord typically just require radiation therapy.

Question 8

The administration of a radioactive drug via the wrong route is an example of a:

Medical event
Reportable miss
Medical occurance
Near miss

Answer 8

Medical event

A medical event, as outlined by the NRC, is an event in which the admistration of a radioactive material results in a dose larger than the prescribed dose by more than 5 rem, total dose differs by more than 20%, fractionated dose differs by more than 50%, wrong drug, wrong route, wrong patient, wrong mode of treatment or leaking source.

Question 9

Indirect action of radiation is the result of the ionization of ___________ surrounding the cell.

proteins
enzymes
water
DNA

Answer 9

water

indirect action is the result of ionizing radiation in the water surrounding the cell in which the molecules are suspended.

Question 10

The current of a CT scanner’s x-ray tube is controlled by:

Display field of view.
mA.
kVp.
Window width.

Answer 10

mA

kVp, or kilovoltage potential, measures the quality or energy of the electrons passing from the cathode to the anode. Display field of view determines how much of the scan field of view and how much of the image can be viewed. Window width determines the range of CT numbers displayed in an image.

Question 11

A common distant metastatic site of bladder cancer is the:

Brain.
Colon.
Lung.
Kidney.

Answer 11

Lung

Local spread is invasion through the bladder wall, invading the muscle layer. Lymphatics involved in cancer of the bladder includes the internal and external iliac node, as well as the presacral nodes.

Question 12

Skin damage, or __________ caused by radiation is evidenced by ulceration and denudation of the skin.

erythema
epilation
alopecia
desquamation

Answer 12

desquamation unintended damage to and loss of the upper layer of skin.

The radiation therapist should check the patient’s skin daily to check for desquamation which may cause an interruption in treatment to allow for healing.

Question 13

The ________________ is used in high-energy linear accelerators to angle the beam within the head of the gantry.

target
circulator
klystron
bending magnet

Answer 13

bending magnet

The bending magnet is used to angle the beam down toward the patient, sometimes even at a right angle.

Question 14

The grainy appearance of a CT image is referred to as image:

Noise.
Spatial resolution.
Contrast.
Reconstruction.

Answer 14

Noise

Spatial resolution is the ability to distinguish two high contrast objects in an image. Contrast is the difference between black and white in an image. Reconstruction refers to taking the data gathered by detectors to create an image with computers.

Question 15

The CT, or Hounsfield, number for fat is:

-1000.
-100.
200.
1000.

Answer 15

-100.

Air, displayed black on an image, has a HU of -1000. Lung tissue ranges between -800 and -300 HU. Bone has a HU between 300 and 1000, displayed white in an image.

Question 16

A formal ______________ is a written legally valid document that indicates a patient’s decisions about future medical treatment.

advanced directive
informed consent
medical notice
medical testimony

Answer 16

advanced directive

An advanced directive is recognized as a legal document and can be a living will or a durable power of attorney for health care or other statement signed by the patient

Question 17

The small bowel joins which component of the large intestine?

Ascending colon
Vermiform appendix
Hepatic flexure
Cecum

Answer 17

Cecum

From the cecum, digestive material travels through the ascending colon to the hepatic flexure, across the transverse colon to the descending colon, sigmoid colon and finally the rectum.

Question 18

Stages of grief including denial, anger, bargaining, depression, and acceptance were introduced by:

Maslow
Kinsey
Kübler-Ross
Karnofsk

Answer 18

Kübler-Ross

The stages of grief were noted by Elisabeth Kübler-Ross. Maslow provided insight for basic needs for all people. Kinsey developed a scale which includes six parameters or sexual tendencies within the population. Karnofsky is associated with the performance scale with ratings from 0 to 100%.

Question 19

In the CT scanner, movable lasers are used to do which of the following? Please select all that apply.

Display field size
Provide isocenter position information
Reposition the CT table
Provide additional illumination

Answer 19

Display field size
Provide isocenter position information

Movable lasers are used in the CT simulation room and communicate with virtual simulation and/or treatment planning systems. While the most common use of these systems is to provide coordinates for the isocenter of the patient’s treatment plan, some systems can project field size, blocks and multileaf collimation onto the patient’s skin. If movable lasers are used in the CT simulation, radiation therapists should complete daily quality assurance on the system.

Question 20

The right and ability of a patient to decide the course of medical treatment is patient ____________.

understanding
communication
autonomy
information

Answer 20

autonomy

Communication to provide important information to enhance patient understanding is an important aspect of the patient’s decision making process, while autonomy is the right of patients to do so.

Question 21

Mean survival time for central nervous system syndrome is approximately _______ days.

10 to 60
20 to 30
4 to 10
0 to 3

Answer 21

0 to 3

At doses greater than 50 Gyt death occurs from CNS syndrome due to elevated fluid content of the brain.

Question 22

Calculate the Mayneord’s factor for a 6 MV photon field treated at 120 cm source to surface distance (SSD), treating to a depth of 7.5 cm.

1. 92
2. 01
3. 03
4. 42

Answer 22

2.03

The Mayneord’s factor is used to correct percent depth dose when treating at extended distances, since percent depth doses are only measured at distances of 100 cm. To calculate Mayneord’s factor, the following equation is used:

Question 23

The area in the brain that is responsible for motor control and the body’s ability to balance is the:
Show More

Brain stem.
Frontal lobe.
Cerebellum.
Parietal lobe.

Answer 23

Cerebellum.

The cerebellum, located behind the brainstem, receives sensory information from other parts of the brain and body and regulates motor movement. It is an especially important structure for voluntary motor movement.

Question 24

The component of the CT scanner that converts light to an electronic signal is the:

X-ray tube.
Detector array.
Photodiode assembly.
Slip ring.

Answer 24

Photodiode assembly.

During a CT scan, the x-ray tube emits photons continuously around the patient. Slip ring technology allows the gantry to move in this fashion. After passing through the patient, the photons are absorbed by the detector array. The detectors covert radiation to light. The photodiode assembly then converts the light to an electronic signal, which is communicated to the computer processors.

Question 25

The maximum field size the linear accelerator can treat at 100 cm is 40 x 40 cm. The physician wants to treat a whole femur in one field, but the length is 52 cm. What treatment distance would you need to treat the femur in one field?

77 cm
90 cm
115 cm
130 cm

Answer 25

130 cm

When the field size needed exceeds the maximum field size of the treatment machine, patients are often treated at extended distances. Similar triangles can be used to determine the treatment distance needed. a/a’ = b/b’; 40/52 = 100/x, x=130 cm.

Question 26

Chemotherapy is indicated for which of the following?

Carcinoma of the vocal cord
Carcinoma in situ of the breast
Locally advanced invasive breast carcinoma
Basal cell carcinoma

Answer 26

Locally advanced invasive breast carcinoma

Chemotherapy is indicated in the treatment of aggressive and/or advanced cancers. A patient with cancer limited to the vocal cord would only need radiation therapy. The same situation applies to a ductal carcinoma in situ (DCIS) breast cancer case. Similarly, basal cell carcinomas typically do not require chemotherapy, but rather radiation alone.

Question 27

For a member of the general public, the maximum exposure of radiation should not exceed ________?

50 mrem/year
100 mrem/year
150 mrem/year
200 mrem/year

Answer 27

100 mrem/year

For a member of the general public, maximum exposure should not exceed 100 mrem in one years’ time. For those who work with radiation, the maximum dose limits for adults increases significantly as follows: 5,000 mrem per year for full body dose, 15,000 mrem per year for lens of the eye exposure and 50,000 mrem per year for extremeties. For an undeclared pregnant radiation worker the maximum dose exposure remains 5,000 mrem per year but, once declared the maximum dose exposure drops to 500 mrem over the time period of the pregnancy.

Question 28

The MOST common malignancy in the pediatric population is:

Leukemia.
Brain tumor.
Soft tissue sarcoma.
Lymphoma.

Answer 28

Leukemia.

Leukemias are the most common malignancy in the pediatric population with acute lymphocytic and acute myelogenous being the most common leukemias in children.

Question 29

Xerostomia occurs after _________ cGy resulting in significant long-term effects.

500
1,000
2,000
3,000

Answer 29

1,000

Xerostomia places the patient at risk for dental caries and oral infections.

Question 30

According to ALARA, which of the following is NOT a principle of radiation safety?

exposure
time
distance
shielding

Answer 30

exposure

The three principles of radiation safety are time, distance, and shielding. Decreasing time of exposure, increasing the distance between the patient and/or care provider and the radiation source, and increasing shielding for the patient and/or care provider.

Question 31

Identifying with the feelings, thoughts, or experiences of another person.

Sympathy
Empathy
Probing
Paraphrasing

Answer 31

Empathy

This term is not necessarily defined as feeling sorry for someone, trying to gather information about them, or in using synonyms to acknowledge that they are being heard.

Question 32

The imaging size of a CT scanner is most dependent on:

Scanned field of view.
Bore size.
Immobilization.
Contrast administration.

Answer 32

Scanned field of view.

Bore, or aperture, size refers to the size of the opening in the gantry of the CT scanner. This opening is typically 70-90 cm in size. However, even if a patient fits through the bore, their entire contour may not be visualized. The scanned field of view determines the image size, and is smaller than the bore size. This can be defined as the amount of anatomy that is scanned, but does have size constraints. Display field of view describes how much of the scanned field of view is reconstructed for the image.

Question 33

Electron beam energy is reduced by _____ MeV per cm in unit density tissue.

1
2
3
4

Answer 33

2

Electrons energy is reduced by 2 MeV per centimeter. This means that a 12 MeV beam at a depth of 2cm is 8 MeV.

Question 34

Whole body exposure to a radiation dose of 1 Gyt results in the _________ period producing acute clinical symptoms that occur within hours.

prodromal
latent
hematologic
gastrointestinal

Answer 34

prodromal

The prodromal period can occur within hours and last for up to 1 or 2 days. Nausea, vomiting, diarrhea and leukopenia can occur.

Question 35

The patient agreement that includes information needed by a reasonable person to make a decision is _____________________.

implied consent
privacy consent
summary consent
informed consent

Answer 35

informed consent

A person’s agreement to allow a procedure or treatment is based on a full disclosure of the facts needed to make an intelligent decision including risks, benefits, desired outcomes, alternatives, refusal, complications, side effects, and mortality.

Question 36

Using a lead apron while taking an x-ray image is an example of which priciple of ALARA?

exposure
time
distance
shielding

Answer 36

shielding

Using a lead apron while taking an x-ray image is an example of shielding. A care provider may wear shielding such as a lead apron or they may use the lead apron on their patient to shield parts of the body they do not want to expose. In each situation the aim is to use shielding to limit radiation exposure and maintain the principles of ALARA.

Question 37

Brachytherapy is administered for which of the following cancers?

Brain
Bone
Cervix
Bladder

Answer 37

Cervix

Brachytherapy is used to treat cervical cancer as a boost therapy following external beam. The purpose is to give additional dose to the tumor, while limiting dose to the bladder and rectum. The other cancers listed are treated with external beam radiation therapy.

Question 38

The treatment planning volume which encompasses suspected positive lymphnode chains is the:

GTV
CTV
PTV
Irradiated volume

Answer 38

CTV

The GTV, or gross target volume, encompasses disease which can be seen on imaging or can be palpated. The PTV, or planning target volume, includes a margin on the CTV to compensate for set-up uncertainties. The PTV margin has decreased with the addition of Image-guided radiation therapy (IGRT). Irradiated volume is anything that receives substantial dose.

Question 39

Surgical excision is the first line of treatment for carcinoma of the:

Larynx.
Lung.
Breast.
Rectum.

Answer 39

Breast

Surgical excision is generally the first line of treatment for breast carcinoma. The other cancers are typically treated with concurrent chemotherapy/radiation therapy unless it is more advanced. For example, advanced cancer of the larynx may require a laryngectomy.

Question 40

Which principle interaction in x-ray production accounts for approximately 75% to 80% of the tubes output and is produced by the sudden deceleration of the high-speed electron as it is deflected around the nucleus of an atom?

characteristic
Compton scatter
bremsstrahlung
pair production

Answer 40

bremsstrahlung

Bremsstrahlung or “braking” radiation is produced as a high-speed electron is deflected around the nucleus of a tungsten atom and accounts for approximately 75-80% of the tube’s output.

Question 41

The parameters for the radiation therapist’s scope of practice is found in the ASRT _________________.

Practice Standards
Code of Ethics
Mission Statement
Regulations

Answer 41

Practice Standards

The ASRT Practice Standards outline the clinical, quality and professional performance and includes the scope of practice for radiation therapists.

Question 42

Which grade would be given to a tumor type depicting cells that look more like normal cells and tend to grow and spread more slowly?

low (G1)
intermediate (G2)
high (G3/G4)
undetermined (GX)

Answer 42

low (G1)

Low grade (G1) tumor cells look more like normal, healthy cells and tend to grow and spread more slowly. High grade tumor cells, alternatively, look abnormal and grow and spread more quickly.

Question 43

__________ is the comparison of a test dose of radiation to a dose of 250 keV x-ray which produces the same biologic effect.

Linear energy transfer
Relative biologic effect
Indirect action
Direct action

Answer 43

Relative biologic effect

Relative biologic effect compares the biologic response by measuring the biologic effectiveness of radiations of different linear energy transfers (LETs).

Question 44

The legal term that describes the actions of a therapist that would be used by another therapist in similar circumstances is _________________.

scope of practice
physical care
standard of care
therapeutic care

Answer 44

standard of care

Scope of care may vary from state to state and facility to facility. The therapist should be aware of the Practice Standards for the profession to be cognizant of current practice.

Question 45

Electronic systems used to identify patients must have at least _____ methods for independent confirmation.

one
two
three
four

Answer 45

two

Electronic systems and patient management systems can be used for independent verification of correct patient, correct treatment and correct site.

Question 46

More pixels in an image matrix results in:

Lower resolution.
Higher resolution.
Lower detail.
Higher distortion.

Answer 46

Higher resolution.

Pixels are associated with resolution. The greater number of pixels, the higher the image resolution.

Question 47

The center number of a range of CT numbers displayed in an image is referred to as the:

Window width.
Voxel.
Pixel.
Window level.

Answer 47

Window level.

The window level refers to the central CT number displayed in an image, while the window width is the range of numbers displayed in an image. By changing these parameters, one can adjust the contrast and/or density of an image in order to see detail in tissues.

Question 48

___________ is the ethical theory that bases decisions on individual motives and morals.

Teleology
Consequentialism
Deontology
Virtue

Answer 48

Deontology

This theory is based on individual motives and morals rather than consequences that may occur as a result of the action or inaction.

Question 49

When should the radiation therapy prescription be signed?

At time of consult
After QA is performed
Prior to the first treament
Within the first three fractions

Answer 49

Prior to the first treament

The prescription must be signed by the radiation oncologist prior to the patient’s first treatment. Electronic signature with date and time stamp is adequate. It is the radiation therapist’s job to check this prior to beaming on each day.

Question 50

What is a common radiation treatment for mycosis fungoides?

Total Body Irradiation (TBI)
Total Skin Irradiation (TSI)
Stereotactic radiotherapy
Single field electron

Answer 50

Total Skin Irradiation (TSI)

Mycosis fungoides is a cutaneous T-Cell lymphoma that mostly affects the skin but may progress to other organs. The patient is assisted into different poses to ensure that all skin surface areas are exposed to the electron beam.

Question 51

Medical ________ can be the result of the patient not being made aware of the potential consequences of the recommended treatment.

autonomy
battery
testing
assault

Answer 51

battery

The concept of informed refusal can be the basis of medical battery if the patient is not informed of the risks of and the potential consequences of refusing the recommended treatment.

Question 52

MV port film image quality is low due to:

Increased scatter.
Decreased scatter.
Increased distance.
Decreased distance.

Answer 52

Increased scatter.

Compton scatter is greater with MV beams than KV beams, thereby reducing contrast and image quality.

Question 53

Which of the following is a sign or symptom of intracranial pressure?

Seizures
Loss of smell
Aphasia
Memory loss

Answer 53

Seizures

Loss of smell, aphasia, and memory loss are all examples of focal signs and symptoms.

Question 54

The intensity of the radiation beam at 1m was 100 mR/hr. What would the exposure be at 2m?

50 mR/hr
25 mR/hr
12.5 mR/hr
10 mR/hr

Answer 54

25 mR/hr

Following the inverse square law, at 2m: 1/(2) squared x 100 mR/hr = 1/4 x 100 = 25 mR/hr

Question 55

The result of indirect action produces an ___________ and _________.

ion pair, free radicals
electron, enzymes
ion pair, enzymes
proton, free radicals

Answer 55

ion pair, free radicals

Indirect action is the result of ionizing radiation in the water surrounding the cell in which molecules are suspended causing an ion pair and free radicals to form.

Question 56

Damage to the _________ cells is the earliest appearance of radiation damage to the skin.

epidermis
basal
dermis
fascia

Answer 56

basal

Basal cells are stem cells that mature in the process of rising to the epidermal surface

Question 57

Which of the following is an indication to screen patients for lung cancer with low dose CT scans?

High exposure to second hand smoke
A 30 pack year smoking history
A smoker who quit 25 years ago
The patient is 40 years of age

Answer 57

A 30 pack year smoking history

Low dose CT screening can decrease the mortality of patients who are at high risk for developing the disease.

Question 58

Which of the following is TRUE regarding grading of the tumor?

A well differentiated cell has a higher grade than a poorly differentiated cell.
Cells that look like the tissue of origin are classified as Grade 4.
Grading can only occur by examining the cancer cells with a microscope.
Grading only occurs if the patient has an oncologic resection of the tumor.

Answer 58

Grading can only occur by examining the cancer cells with a microscope.

A Grade 1 classification is given to cells that are well differentiated, thus look like their tissue of origin. Grade 4 cells are cells that are undifferentiated or anaplastic, and difficult to discern their original tissue of origin.

Question 59

An exchange of information, thoughts, or messages using methods other than actual words of speech.

Verbal Communication
Nonverbal Communication
Emotional Intelligence
Paralanguage

Answer 59

Nonverbal Communication

Nonverbal communication is the exchange of information, thoughts , or messages using methods other than actual words

Question 60

When would a wedge be used in a treatment field?

To compensate for missing tissue
To increase skin dose
To block the center of the field
To minimize penumbra

Answer 60

To compensate for missing tissue

Wedges can be used to compensate for missing tissue. The heel of the wedge is placed towards the missing tissue. Wedges are also used to correct dose nonuniformity.

Question 61

Patients receiving breast external beam irradiation may be positioned in all of the following positions, EXCEPT:

Prone.
Supine.
Decubitus.
Standing.

Answer 61

Standing.

Breast cancer treatment delivery may be conducted in all positions except standing. Supine treatment is most common, especially for women with smaller breasts. Prone is best suited for women with larger breasts and those with left side lesions where treatment may better spare the heart. More rarely, patients may be treated in the lateral decubitus position.

Question 62

Radiation treatments in which the total dose is divided into small doses and delivered more than once a day is termed:

Hyperfractionation.
Hypofractionation.
SBRT.
Concurrent.

Answer 62

Hyperfractionation.

Hyperfractionation refers to radiation treatments in which the total dose is divided into smaller doses and delivered more than once a day, with treatments typically being delivered 6 hours or more apart. Benefits to hyperfractionation include reduced side effects and total treatment dose may be higher.

Question 63

A cancerous tumor of the glandular tissue would likely be classified as a:

Adenocarcinoma.
Neuroma.
Leiomyosarcoma.
Squamous cell carcinoma.

Answer 63

Adenocarcinoma.

Squamous cell carcinomas originate from tissues with squamous cell epithelium, such as the head and neck, lung, cervix, anus and vagina. Neuromas are a benign tumor of the nerves, as indicated by the -oma suffix. Finally, sarcomas are cancers of the connective tissue. A leiomosarcoma is a tumor of the smooth muscle.

Question 64

Myelopathy can occur with radiation doses of _____ Gy using QUANTEC tables for conventional fractionation.

20
30
40
50

Answer 64

50

Myelopathy has a toxicity rate of 0.2% at 50 Gy after conventional therapy and increases significantly at 60 and 69 Gy.

Question 65

What is the basis of a pixel in digital imaging?

Volume elements
Three-dimensional
Picture elements
Used in MRI

Answer 65

Picture elements

Numbers are collected, stored, and reconstructed to form pixels, which are picture elements. This is the basis for two-dimensional CT imaging.

Question 66

Average tissue-to-air ratio (TAR) is used when calculating monitor units for which type of treatment fields?

Rotational fields
En face electrons
Parallel opposed fields
Four field box

Answer 66

Rotational fields

When calculating monitor units for rotational fields, several calculation factors are used. Because the depth to the target differs throughout the rotation, an average TAR is used. Historically, TAR was measured every ten degrees and then averaged. Current treatment planning systems have a more sophisticated method for calculating average TARs.

Question 67

Radiation therapy is the first line of treatment for which of the following cancers?

Leukemia
Larynx
Hodgkin lymphoma
Breast

Answer 67

Larynx

Radiation therapy is typically the first line of treatment for head and neck cancers, unless the disease is too advanced and surgery may be advised. Breast cancer patients typically undergo surgical excision as the first treatment, and lymphomas and leukemias are generally treated with chemotherapy.

Question 68

If the treatment machine has an isocenter distance of 100 and the field width is 14 cm, what is the field size at isocenter with a target-skin distance (TSD) of 91 cm?

12. 9 cm
13. 2 cm
14. 6 cm
15. 1 cm

Answer 68

15.2 cm

Similar triangles can be used to determine field size at different depths with photon fields. The formula is a/a’ = b/b’.

Question 69

By which two lymph node routes does ovarian cancer spread MOST often?

para-aortics and pelvic
cervical and intramammary nodes
para-aortics and intestinal
pelvic and cervical

Answer 69

para-aortics and pelvic

Ovarian cancer can spread by a variety of different routes. In reference to lymph node metastasis, owing to the location of ovarian cancer, lymph node metastasis may most commonly occur via the para-aortic and pelvic lymph nodes. The para-aortic lymph nodes lie in front of the lumbar vertebrae, near the aorta while the pelvic lymph nodes lie adjacent to the pelvic organs and include the inguinal, internal, external and common iliac, obturator and sacral nodes.

Question 70

The term used to describe table movement per rotation divided by slice thickness is:

Voxel.
Hounsfield unit.
Roll.
Pitch.

Answer 70

Pitch.

Pitch describes table movement per rotation divided by slice thickness. When pitch is less than 1, there is overlap between rotations. While the image quality is high (because no information is missed between slices), the scan dose is also high. When pitch is greater than 1, image quality is less because there is no overlap of scan rotations. This results in missing information between the rotations, which the computer attempts to reconstruct.

Question 71

When viewing an axial pelvis image of a supine patient, which structure would be most anterior?

Prostate
Rectum
Pubis
Coccyx

Answer 71

Pubis

In a supine pelvis image, the pubis would be most anterior. Next would be the prostate, then rectum and finally the coccyx. The bladder and seminal vesicles would be visualized in superior slices.

Question 72

Cataracts can occur after radiation doses of __________ cGy to the whole organ.

50
100
200
1,000

Answer 72

1,000

Question 73

When treating with two fields 120 degrees apart, what is the most appropriate wedge angle to be used?

15 degrees
30 degrees
45 degrees
60 degrees

Answer 73

30 degrees

When combining two fields, wedges are used to improve dose conformity. To determine the angle of the wedges needed, first determine the hinge angle. The hinge angle is the angle between the central axis of both fields. Next, the wedge angle can be calculated with the following formula: Wedge angle = 90 - (Hinge angle/2). In this example WA = 90 - (120/2) = 30 degrees.

Question 74

Non-small cell lung cancer commonly metastasizes to the:

Bladder.
Liver.
Kidney.
Brain.

Answer 74

Brain

Non-small cell lung cancer will commonly metastasize to the brain via the blood stream. Prognosis with brain metastasis is generally poor. Whole brain irradiation may be delivered for palliative care or prophylactically as a means of prohibiting metastasis.

Question 75

Where do medulloblastomas typically metastasize to?

Lung
Bone
Liver
Kidney

Answer 75

Bone

Medulloblastomas commonly metastasize distantly to the bone via the bloodstream and are also known to spread rapidly through craniospinal fluid.The most common bone sites for metastasis include the pelvis, long bones, and spine.

Question 76

Halfway through treatment, the radiation theraptist notices that the table angle has drifted out of tolerance by 5 degrees. What should the radiation therapy do?

Continue with treatment
Stop treatment, realign the patient, continue treatment and then notify the doctor
Stop the treatment and get the patient off the table while you notify the doctor
Call physics to determine why the table was turned

Answer 76

Stop the treatment and get the patient off the table while you notify the doctor

Always stop treatment if you see a mistreatment is occurring. Notify the doctor of the incidence and consult with physics to determine the best way to rectify mistreatment.

Question 77

In the TNM staging system, a Tx would indicate:

1 - 3 cm tumor.
Tumor cannot be evaluated.
Tumor > 5 cm.
In situ tumor.

Answer 77

Tumor cannot be evaluated.

In the TNM staging system, T represents the status of the tumor. T0 indicates a tumor that cannot be found (for example - in an unknown primary). Tis represents in situ disease. T1-T4 indicates the size and/or extent of invasion. While the specifics differ for each specific cancer, T1 is the most favorable while T4 is the least favorable.

Question 78

What methods are acceptable to use when identifying a patient? Please select all that apply.

Hospital identification bracelet.
Having the patient spell their last name
Having the patient state their birthdate
Treatment set-up photo

Answer 78

Hospital identification bracelet.
Having the patient spell their last name
Having the patient state their birthdate

At least two methods should be used. Asking the patient where they are being treated is also part of the daily time out.

Question 79

This term includes home, respite, inpatient hospital care and support during bereavement.

Hospice Care
Critical Care
Long-term Rehabilitation Care
Skilled Nursing Facilities

Answer 79

Hospice Care

Hospice services include home, respite, inpatient hospital care and support during bereavement. The durable power of attorney is a legal document that allows an individual over the age of 18 years to be designated as a surrogate and decision maker of matters concerning health care. The living will is a legal document which allows a competent adult to provide direction to health care providers concerning their choice of treatment if the individual is no longer competent by reason of illness or other infirmity to make those decisions. Both the living will and durable power of attorney are considered advanced directives.

Question 80

When treating with multiple fields, what is TRUE regarding beam weighting?

The beam that is further from the tumor is given higher weight
Beam weighting is most useful when the target is midplane
Beam weighting is useful when treating through a sensitive structure
Beam weighting is only used when three or more fields are used

Answer 80

Beam weighting is useful when treating through a sensitive structure

Beam weighting can be used whenever multiple beams are used. Weighting of the fields is useful when the target is not located at midplane, or when the beams pass through a sensitive structure. Beams that are closest to the target are weighted more to pull the dose to the target, and the beam farther from the sensitive structure is weighted more to pull dose away from it.

Question 81

In digital imaging, what is a characteristic of a voxel?

Three-dimensional
Two-dimensional
Picture elements
Not used in CT

Answer 81

Three-dimensional

CT scan images are made up of three-dimensional voxels and two-dimensional pixels. The combination of the two helps improve image quality

Question 82

What part of the linear accelerator is responsible for the production of electrons and injecting them into the accelerator structure?

klystron
magnetron
electron gun
accelerating waveguide

Answer 82

electron gun

The electron gun is responsible for the production of electrons and injecting them into the accelerator structure.
Previous

Question 83

4D respiratory gating is significantly useful for treating tumors in all of the following, EXCEPT:

Bone.
Breast.
Lung.
Abdomen.

Answer 83

Bone

respiratory gating is ideal for treatment sites where the tumor may move due to patient breathing or where patient anatomy may shift. Examples of treatment sites that are best suited for 4D treatment include lung, breast, and abdomen.

Question 84

The rate at which energy is deposited per unit distance as radiation passes through matter is ________________.

linear energy transfer
relative biologic effect
indirect action
direct action

Answer 84

linear energy transfer

Linear energy transfer is the energy deposited as a charged particle travels through matter and is a function of the mass and charge of the radiation.

Question 85

Which of the following variations from treatment would be considered a systemic error?

Bolus was omitted for one fraction
Imaging was completed on fraction 7 rather than fraction 6
Wrong electron cutout was used for one day of the boost treatment
Wrong monitor units (MU) were inputed and used for the entire course of treatment

Answer 85

Wrong monitor units (MU) were inputed and used for the entire course of treatment

ystemic errors may take place in planning or when entering data into the record and verify system.

Question 86

Under the new standards (NCRP Report No. 91), an effective dose equivalent limit of ____rem/year for occupational exposure is recommended.

5
25
35
40

Answer 86

5

The NCRP report states the 5 rem/year is the acceptable limit for occupational exposure.

Question 87

The first echelon lymph node for prostate cancer is the ____________ nodes.

Inguinal
Obturator
Periaortic nodes
Presacral

Answer 87

Obturator

The obturator node is one of the first lymph nodes involved when prostate cancer spreads through the lymphatics, followed by the external iliacs, hypogastric and common iliac nodes. Distantly, prostate commonly spreads to the bone.

Question 88

Output factors used in monitor unit calculations for photon fields are measured using what field size?

5 x 5 cm
10 x 10 cm
15 x 15 cm
20 x 20 cm

Answer 88

10 x 10 cm

Output factors are measured with a 10 x 10 cm field size. When treating with a field size other than 10 x 10 cm, a field size correction factor is used. This correction factor is dependent on treatment machine and treatment energy. The field size correction factor is built into treatment planning systems.

Question 89

A wheelchair should be placed at a _______ degree angle to the table.

15
30
45
60

Answer 89

45

A 45 degree angle of wheelchair to table will provide the patient with sufficient room to pivot.

Question 90

The annual whole body effective dose limit for an occupational worker recommended by the NCRP is:
5 rem
10 rem
20 rem
25 rem

Answer 90

5 rem

For an adult occupational radiation worker, the recommended annual whole body dose limit is 5 rem (5,000 mrem). Dose limit per year for lens of the eye is 15,000 mrem and exposure for extremeties is 50,000 mrem. For a member of the general public, maximum exposure should not exceed 100 mrem in one years’ time.

Question 91

Which of the following skin cancer histologies is MOST likely to spread distantly to the lung?

Basal cell carcinoma
Squamous cell carcinoma
Multiple myeloma
Melanoma

Answer 91

Melanoma

Basal cell carcinoma and squamous cell carcinoma are typically localized and spread by direct extension. Of the two histologies, squamous cell carcinoma is more likely to metastasize.

Question 92

hat is the primary benefit of prone breast irradiation?

Patient comfort
Decreased skin dose
Fewer treatments
Decreased heart dose

Answer 92

Decreased heart dose

The primary purpose of prone breast irradiation is to limit the dose to the heart. This is often the ideal technique for large breasted patients with a left-sided breast cancer. Since the heart is more towards the left, dose would be greater if the patient was in the supine position. The prone position allows the breast tissue to fall away from the chest wall, limiting heart dose.

Question 93

Stereotactic radiation to tumors of the brain is known as:

SRS.
SBRT.
IMRT.
intercranial irradiation.

Answer 93

SRS.

Stereotactic radiosurgery (SRS) treatment is a focused radation treatment technique. It is commonly used to treat small tumors in the brain and spinal cord.

Question 94

When paper charts and forms are in use, what is acceptable when making changes?

Correction tape (White-out)
Several lines to cross out original entry
Writing correct entry over original entry
Single line to cross out entry with charting person's initials and date of correction

Answer 94

Single line to cross out entry with charting person’s initials and date of correction

hen making changes to the patient chart, the initial entry should be crossed out with a single line, accompanied by the charting person’s initials and date. There should not be an attempt to obscure the original entry.

Question 95

Damage by ionization of a biologic macromolecule is caused by _______ action.

indirect
direct
capture
release

Answer 95

direct

Direct action occurs when any macromolecule of the cell is ionized. The damage is caused by direct absorption of the radiation resulting in damage to the DNA, RNA, protein, enzyme, etc.

Question 96

What step would occur after a patient has been set up in the treatment position and a verification cone beam has been completed?

Treatment is paused
Prescription is changed
Patient is removed from table
Minor adjustments to alignment are made

Answer 96

Minor adjustments to alignment are made

After the patient has been set up appropriately and verification image-guided radiation therapy (IGRT) imaging has been completed, ensuring that shifts are also appropriate, the treating therapist would then apply the isocenter shifts according to the IGRT alignment. Upon completion, the patient and their final position would be ready for treatment delivery.