SEAL #6

Question 1

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)

Answer 1

Patient AP and lateral measurements
source to axis distance (SAD)

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

Question 2

Patients taking metformin should stop taking the medication ______ hours before having contrast administration for a CT simulation.
12
24
36
48

Answer 2

48

The American College of Radiology recommends discontinuation of metformin 48 hours prior to contrast administration to avoid risk of lactic acidosis

Question 3

When checking the lasers used in radiation therapy, they must be accurate within:
1 mm
2 mm
3 mm
2%

Answer 3

2 mm

Daily localizing lasers must be within 2 mm of accuracy

Question 4

What photon interaction dominates at 50 MeV?
Photoelectric effect
Coherent scattering
Compton effect
Pair production

Answer 4

pair production

Compton effect dominates at energies between 25 KeV and 10 MeV, which encompasses any therapeutic radiation energies. Photoelectric effect dominates at energies less than 25 KeV, most often used in diagnostic equipment.

Question 5

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

Answer 5

1,917

5,750 cGy / 3 = 1,916.66 cGy

Question 6

__________ 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

Answer 6

Quantec

Emami data/doses were used in the 2D treatment planning arena. Quantitative Analysis of Normal Tissue Effects in the Clinic, also known as Quantec, was published with improved toxicity data for the radiation patients. It looks at normal tissue toxicities, volumes and doses with how they are distributed in a treatment plan.

Question 7

The monthly equivalent dose limit for pregnant radiation workers should not exceed ________ per month.
0.1 mSv
0.5 mSv
1 mSv
5 msv

Answer 7

0.5 mSv

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.

Question 8

A measure of machine output from a linear accelerator is defined as a:
monitor unit
minute of time
dose
energized unit

Answer 8

monitor unit

A monitor unit (MU) is defined as a measure of machine output from a clinical accelerator for radiation therapy. It is the output measurement of radiation exposure. Monitor units delivered to a patient are determined during the planning portion of their treatment. Monitor units may depend on dose, treatment site, patient size, energy of the treatment unit, distance and field size

Question 9

Afterloading techniques _________ exposure to operating room personnel and radiation therapists.
increase
decrease
intensify
double

Answer 9

decrease

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

Question 10

Which of these tumors arises from epithelium?

• Ewing sarcoma
• Osteosarcoma
• Hodgkin lymphoma
• Adenocarcinoma

Answer 10

adenocarcinoma

Carcinomas arise from epithelial tissue, whereas sarcomas form from connective tissue. Lymphomas arise in the lymphatic system

Question 11

The pharynx is divided into 3 sections. Which of the following sections is called the epipharynx?
Hypopharynx
Laryngeopharynx
Nasopharynx
Oropharynx

Answer 11

nasopharynx

The nasopharynx/epiphraynx is the uppermost portion of the pharynx. It runs from the nasal cavity to the soft palate. It serves as a pathway for air during breathing

Question 12

Tuberculosis is an example of an infection by which route?
Contact
Droplet
Airborne
Blood borne

Answer 12

airborne

Tuberculosis can be spread very easily, and in the past has spread in hospitals because of air recirculation and low airflow rates.

Question 13

Cell differentiation is referred to as:
Stage.
Histologic type.
Grade.
Sensitivity

Answer 13

Grade

Tumor grade refers to the aggressiveness and differentiation. Tumors may be classified as well differentiated, moderately well differentiated, poorly differentiated, or undifferentiated.

Question 14

______ 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

Answer 14

Autofielding

The autofield should include a margin around the PTV that allows for beam penumbra and block edge effects and allow isodose line of 90% or greater to cover the PTV.

Question 15

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/d

Answer 15

0.8 mg/dL

A creatinine level greater than 1.4 could indicate the kidneys would have difficulty excreting the contrast material. This would be a contraindication to contrast administration.

Question 16

Calculate the hinge angle between two fields if a patient is being treated with 30-degree wedges.
90
120
150
180

Answer 16

120

Use this formula to calculate hinge angle. HA = 180-2(wedge angle). It is defined as a measure of the angle between central rays of 2 intersecting treatment beams. The amount of tilt that an isodose curve has is dependent on the size of the wedge used. Wedges with a larger incline or degree have more of an isodose tilt.

Question 17

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

Answer 17

thermoluminescent (TLD)

Use this formula to calculate hinge angle. HA = 180-2(wedge angle). It is defined as a measure of the angle between central rays of 2 intersecting treatment beams. The amount of tilt that an isodose curve has is dependent on the size of the wedge used. Wedges with a larger incline or degree have more of an isodose tilt.

Question 18

Conditions acquired in the hospital setting are known as:
Bacterial infections.
Isolation infections.
Medical infections.
Nosocomial infections.

Answer 18

nosocomial infections

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.

Question 19

Permanent alopecia is seen in radiation doses that reach ___ Gy
25
30
40
45

Answer 19

45

Alopecia may develop during the course of radiation treatment depending on the area of the body being treated and often is reversible after treatment concludes. Modern radiation therapy treatment techniques aim to spare skin, thus sparing the hair follicles and reducing the likelihood of permanent alopecia

Question 20

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

Answer 20

pulsed-dose rate

A remote afterloader similar to an HDR unit is used to deliver short pulses of radiation.

Question 21

Of the following tumors, which is more likely to be well differentiated?
Squamous cell carcinoma of the cervix
Andenocarcinoma of the lung
Meningioma
Osteosarcoma

Answer 21

Meningioma

Meningiomas are usually benign; the other diseases listed are malignant and can be more aggressive

Question 22

MOST importantly, a patient being treated for Hodgkin’s disease must be monitored for:
Myelosuppression.
Nausea and vomiting.
Weight loss.
Neural signs.

Answer 22

myelosuppression

It is important to monitor a Hodgkin’s disease patient for myelosuppression as a large quantity of bone marrow is irradiated in the treatment field of these patients which can lower immunity.

Question 23

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.

Answer 23

control console

Controlled areas are defined as a limited access area in which the occupational exposure of personnel to radiation producing equipment is supervised. Of these, the only one that is supervised is the control console.

Question 24

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

Answer 24

fractionation

Fractionation can occur once or twice daily. If a patient receives 3,000 cGy at 300 cGy once daily, the fractionation will be 10.

Question 25

Brachytherapy __________ categories are based on the relationship between the rate of tumor cell proliferation and treatment duration. half-life substitute dose rate isotope

Answer 25

dose rate The categories are low (0.3 - 2 Gy/h), medium (2 - 12 Gy/h) or high dose rate (greater than 12 Gy/h).

Question 26

_________ 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

Answer 26

beam-on indicators Warning lights provide visual cues indicating when the beam is on. Audible devices indicate the end of the treatment.

Question 27

The MOST common metastatic site for prostate cancer is the: Brain. Bone. Lung. Liver.

Answer 27

bone Prostate cancer metastasizes to bone 90% of the time, followed by lungs and liver.

Question 28

The _____ portion of the wedge allows for less transmission of photons. Heel Lateral Middle Toe

Answer 28

heel Wedges are used on sloping surfaces. The thick end is called the heel and the thin end is called the toe. The thinner end will allow for more transmission of the radiation beam.

Question 29

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

Answer 29

fiducial A fiducial can be implanted in a patient, typically at the tumor bed, and can give a visual coordinate system for which to base planning.

Question 30

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

Answer 30

dose clouds Dose distributions are best displayed as isodose lines for 2D planes and as dose clouds for 3D planning. 3D dose clouds allows the planner to see if any portion of the planning target volume (PTV) extends outside of the isodose cloud and is not properly covered.

Question 31

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

Answer 31

Host-infectious microorganism-reservoir-mode of transmission This cycle is a continuous loop wherein an infectious agent or microorganism is able to survive within a reservoir (a person, animal, or environmental component), be transmitted through a mode of transmission and finally reside within a new host. Each link has a role in the cycle and each can be interrupted or broken in various ways.

Question 32

Of the following staging scenarios, which is the most advanced? T1N0M0 T0N1M0 T1N1M0 T0N2M0

Answer 32

T0N2M0 T0N2M0 is the most advanced, as the level of lymph node involvement is greater than the others. Regardless of tumor size, once lymph nodes are involved, the staging advances.

Question 33

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

Answer 33

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

Question 34

A tumor assigned a grade of G4 indicates the tumor is: Well differentiated Moderately differentiated Poorly differentiated Undifferentiated

Answer 34

undifferentiated A tumor assigned a G4 is undifferentiated, or more aggressive. The degree of differentiation is greater in a high-grade tumor than a low-grade tumor.

Question 35

Half value layer can be calculated with which of the following equations? I1/I2 = (d2/d1)2 0.693/μ A0e-λt ln2/λ

Answer 35

0.693/μ Half value layer, or HVL, is the amount of material necessary to attenuate a beam to half of its original intensity.

Question 36

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

Answer 36

2,400 cGy : 3,600 cGy The left side would get more radiation due to the field being weighted more than the right. Take the total dose (6000cGy) and divide it by the total parts (5 parts: 2 from the right and 3 from the left) 6,000 cGy/ 5 = 1,200 cGy per part. For the right side: 1,200 cGy x 2 parts= 2,400 cGy and the left side: 1,200 cGy x 3 parts= 3,600 cGy

Question 37

Seizures are separated into which two groups? Generalized seizures and focal seizures Acute and chronic Short and long Tonic and clonic

Answer 37

Generalized seizures and focal seizures Seizures are separated into two groupings based on how and where they begin in the brain.

Question 38

Which of the following tumors originates from smooth muscle? Rhabdomyosarcoma Neuroblastoma Angiosarcoma Leiomyosarcoma

Answer 38

leiomyosarcoma The term "leio" refers to smooth muscle. Therefore, leiomyosarcoma originates from smooth muscle. Angiosarcoma arises from blood vessels, and neuroblastoma arises from nerve cells.

Question 39

CT number for accuracy with water is checked on a _____ basis in a CT simulator. Daily Weekly Monthly Annually

Answer 39

daily At monthly QA, CT number accuracy is checked for four to five different materials with varying materials.

Question 40

The range of electrons in water for a 12 MeV beam is: 3 cm 4 cm 6 cm Infinite

Answer 40

6 cm The approximate depth of the 80 and 90% isodose line can be determined by R80= E/3, and R90 = E/4.

Question 41

Which of the following malignancies is MOST likely to invade lymph nodes? Chondrosarcoma Squamous cell carcinoma Liposarcoma Ewing sarcoma

Answer 41

squamous cell carcinoma Carcinomas arise from epithelial cells, which are located in superficial surfaces all over the body. Epithelial cells form glands, which makes lymph nodes more likely to be affected by carcinomas

Question 42

Anaphylactic shock may occur during which of the following procedures? immobilization device creation tattoo skin marking contrast administration brachytherapy

Answer 42

contrast administration Anaphylactic shock, an extreme, possibly life-threatening allergic reaction, can occur during contrast administration. Although tattoo skin marking, immobilization device creation, and brachytherapy are all situations in which caution must be taken, they do not use agents that would lead to an anaphylactic shock response.

Question 42

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.

Answer 42

Supine with arms at side. A thermoplastic mask and IV contrast are used. Supine with arms at side and a thermoplastic mask and IV contrast is the best answer as immobilization is the key for reproducing the patient setup. Without the mask, the precious target coverage will be lost, therefore missing the appropriate treatment volume.

Question 42

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

Answer 42

twice a day treatments (BID) three times a day treatments (TID) When BID (twice a day) radiation treatment is utilized, treatments must be delivered at least 6 hours apart. Delivering treatment 6 or more hours apart ensures that normal tissues are allowed time to completely repair from the previous fraction.

Question 43

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

Answer 43

91 cm on both sides This question requires figuring out the depth to each side. The right side is 8 cm and the left is 10 cm. Add each depth together to get the patients total separation, 18 cm. To treat to midline, divide the separation in half, 18 cm/ 2= 9 cm from each side. The isocenter is at 100 cm therefore you need to subtract the depth from the isocenter distance. 100 cm - 9 cm = 91cm (from each side).

Question 43

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.

Answer 43

The beam energy and the thickness of the mask. Studies have been done to prove there is a reduction of skin sparing when using thermoplastic masks for radiation treatments. There is an increased dose to the skin the first few millimeters. Also non-perforated sheets have shown to have more of a skin dose than perforated. The true skin dose can be difficult to determine due to the variability in thickness and perforations within and between different masks.

Question 44

Two fields that are separated by 180 degrees are termed? Parallel opposed beams Tangents Orthogonal beams Laterals

Answer 44

Parallel opposed beams Two beams separated by 180 degrees are termed parallel opposed beams. Orthogonal images are 90 degrees apart, and laterals are describing the location of the beam in regards to the patient. Tangents are fields used in breast treatment. They may be 180 degrees apart, but not necessarily.

Question 45

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

Answer 45

absorbed; photoelectric interaction The photoelectric interaction involves the absorption of the energy of an x-ray photon by an inner shell electron.

Question 46

What is the single most important means of preventing the spread of infection? Using personal protective equipment Wearing gloves Coughing into shoulder Hand washing

Answer 46

hand washing Hand washing is the single most important means of preventing the spread of infection. Hand washing can prevent the spread of germs, including those that are resistant to antibiotics. The most common means of hand washing include using an alcohol-based hand sanitizer and washing thoroughly with soap and water.

Question 47

Which of the following has the longest wavelength? UV rays Visible rays Microwaves Gamma rays

Answer 47

microwaves Of these, microwaves are the furthest to the left in the electromagnetic spectrum, thus having the longest wavelength, followed by visible rays, UV rays and finally gamma rays. Wavelength and frequency are inversely related.

Question 48

Which of the following does not take attenuation of a radiation beam into account? Bolus Cerrobend block Compensator Target

Answer 48

target Anything placed in the beam is attenuated and an attenuation factor must be applied to the calculation in order for the correct amount of radiation to be delivered.

Question 49

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

Answer 49

beams eye view Not all treatment fields can be imaged. The use of BEV images should be considered to verify correct placement of the treatment plan isocenter relative to the patient anatomy. This should be done with the patient on the treatment table in the correct treatment position.

Question 50

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

Answer 50

scattered; Compton The interaction that occurs between the outer shell electron and the x-ray photon is known as the Compton interaction and the remnant photon is scatter radiation.

Question 51

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

Answer 51

Bismuth, lead, tin, cadmium Cerrobend blocks, such as those used in lead block shielding or for electron radiotherapy, are made using the combination of bismuth, lead, tin, and cadmium. Cerrobend has a low melting point and has been a reusable resource in many radiation therapy departments. Recently, some departments have transitioned to a form of Cerrobend that is cadmium-free as cadmium has been shown to have toxic properties.

Question 52

Seminoma of the testes arises from: Sweat glands. Nerve cells. Germ cells. Fibrous tissue.

Answer 52

germ cells At least 95% of seminomas arise from germ cells. There are 3 subtypes: classic, anaplastic, and spermatocytic. The immature nature of germ cells causes increased sensitivity; therefore a lower radiation dose is necessary.

Question 53

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

Answer 53

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

Question 54

Which of these contrast reactions is considered minor? Dyspnea Nausea Syncope Cardiac arrhythmia

Answer 54

nausea Compared to the other reactions, nausea is considered minor because treatment would not be required

Question 55

________ scattering takes place at the level of an outer shell electron. Unmodified Compton Coherent Classical

Answer 55

Compton The interaction between the incident photon and the outer shell electron produces Compton (modified) scatter.

Question 56

Surface brachytherapy is MOST commonly used to treat ___________ skin cancer. melanoma nonmelanoma basal squamous

Answer 56

nonmelanoma 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.

Question 57

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.

Answer 57

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

Question 58

The anatomical location of the hilum of the kidneys is located at: T5 - T6 T12 - L2 L1 - L5 S1 - S3

Answer 58

T12-L2 The kidneys are retroperitoneal with the right kidney lower, due to the liver pushing it downward. The hilum of the right kidney sits at L2 and the hilum of the left kidney sits at L1

Question 59

Collision interlocks of the on board imagers should be checked. Daily Weekly Monthly Annually

Answer 59

daily 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.

Question 60

When treating pancreatic cancer, what target volume does not have to be routinely identified? Kidneys Liver Rectum Small Bowel

Answer 60

rectum As recommended by The International Commission on Radiation Units and Measurements (ICRU) report 62, other routine anatomy that needs to be identified is the spinal cord. This is due to the location and dose received as critical structures in that treatment area. Total GTV dose is between 50.4 to 54Gy. All the organs at risk tolerance doses are higher than the prescribed doses.

Question 61

A patient suffering from hypoglycemia should be offered: Orange juice sweetened with sugar. A salad. Coffee. Water.

Answer 61

Orange juice sweetened with sugar. 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.

Question 62

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

Answer 62

L4 The common iliac nodes side at the bifurcation of the common iliac arteries. The bifurcation of the common iliacs comes off the abdominal aorta at the level of L4

Question 63

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

Answer 63

measurement of electron beams output constancy checks instananeous response Silicon diodes are useful due to their high sensitivity, instantaneous response, and small size. They are also used for patient dose monitoring.

Question 64

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

Answer 64

To block the exit beam and protect the nasal septum Lead may be inserted into a cavity beneath a primary field in order to block the exit beam and reduce dose to structures below the surface.

Question 65

A cancer cell that is similar to the cell of origin is: Well differentiated. Moderately well differentiated. Poorly differentiated. Undifferentiated.

Answer 65

well differentiated Well differentiated tumor cells are most similar to the original cells. This means they are less aggressive and typically carry a more favorable prognosis.

Question 66

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

Answer 66

timing the radiation beam is on An example of gating would be when the beam is on within the breathing cycle when treating lung cancer. This occurs during the resting phase of the breath, on expiration.

Question 67

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

Answer 67

Interlocks Interlocks will prevent machine operation when something is incorrect. Interlocks are designed to protect patients, staff and the equipment. Additional examples of interlocks include door interlocks, time delays, pressure and temperature interlocks, and many more.

Question 68

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

Answer 68

Determine the degree of cell differentiation The purpose of cancer staging is to define the tumor size, determine optimal treatment, and determine the degree of lymph node invasion. Grading is the process to determine the degree of cell differentiation.

Question 69

Mechanical tolerance for stereotactic radiation therapy treatment delivery should be within ________. ± 2 mm ± 3 mm ± 2 cm ± 3 cm

Answer 69

± 2 mm ACR practice guidelines state that the delivery treatment should be within ± 2 mm for mechanical tolerances.

Question 70

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

Answer 70

photoelectric 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.

Question 71

The point of intersection of the gantry, collimator, and base of the couch is the ___________. treatment plan isocenter BEV PTV

Answer 71

isocenter Isocenter is the intersection of the three axes of machine rotation, gantry, collimator and base of couch

Question 72

The carina is generally located at which of the following vertebra? C7 T5 T8 T12

Answer 72

T5 The bifurcation of the trachea into the right and left main stem bronchus is called the carina. The carina generally sits at T4 - T5.

Question 73

A stage II skin reaction is depicted by: Erythema Moist desquamation Dry desquamation Necrosis

Answer 73

dry desquamation A stage II skin reaction follows erythema. It results in dry, flaky skin and is referred to as dry desquamation. It is usually itchy and can be treated with a mild topical steroid. Further radiation can cause the skin to break down changing dry desquamation into moist desquamation and, rarely, to ulceration. Skin reactions tend to worsen as treatment continues and often reaches its worst point a week following the completion of treatment.

Question 74

A supervised limited access radiation area such as the treatment room is a ___________ area. patient workload controlled uncontrolled

Answer 74

controlled A controlled area is supervised by a person trained in radiation protection and includes the treatment room, console control, and any adjacent treatment rooms

Question 75

Which of the following is recommended for patients undergoing pelvic radiation? Low protein diet High fat diet High fiber diet Low fiber diet

Answer 75

low fiber diet A change in bowel habits is a common side effect of radiation therapy to the pelvic area. To assist patients during this time a low-fiber, or low-residue, diet is recommended for patients receiving pelvic irradiation. Eating a diet low in residue such as fiber, fat, and some milk or vegetable products, helps to reduce the frequency of bowel movements, which may help reduce or prevent diarrhea.

Question 76

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

Answer 76

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

Question 77

Breast tumors are most commonly located in the _____________quadrant. Upper inner Upper outer Lower inner Lower outer

Answer 77

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

Question 78

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

Answer 78

20 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.

Question 79

Strep throat is an example of infection by: Virus Bacteria Fungus Protozoa

Answer 79

bacteria Strep throat is an example of infection by bacteria. It is contagious and can be treated with antibiotics.

Question 80

The unit used to measure the wavelength associated with x-ray energy is the: angstrom. joule. hertz. electron volt.

Answer 80

Angstrom A unit of length equal to one hundred-millionth of a centimeter(10-10meter), the angstrom is used mainly to express wavelengths of electromagnetic radiation.

Question 81

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.

Answer 81

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

Question 82

What is the anatomical landmark for angle of the mandible? C1 C3 C5 C7

Answer 82

C3 The angle of the mandible is approximately 6 cm below the external occipital protuberance and associated with cervical spine C2 - C3. Also, the hyoid bone is approximately 1 cm below the angle of the mandible when the head is in a neutral position.

Question 83

A mild allergic reaction can present with: itching and urticaria laryngeal tightening shock cardiac arrest

Answer 83

itching and urticaria A mild allergic reaction presents with itching and urticaria (hives). Mild allergic reaction symptoms can progress to severe symptoms if not treated. Sudden severe allergic reaction symptoms, such as in the case of anaphylaxis, can include laryngeal tightening, shock, and cardiac arrest.

Question 84

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

Answer 84

450 mSv The cumulative effective dose to the whole body for occupational workers is calculated by multiplying the person's age by 10 mSV. (45 years)10 mSv = 450 mSv

Question 85

An example of an attenuation quality assurance test for MLC includes: Leaf speed Leaf transmission Leaf position accuracy Verification of MLC field

Answer 85

Leaf transmission Leaf transmission is an example of an attenuation test. Other categories of MLC tests include positional precision tests (such as leaf speed), position accuracy, and field shaping.

Question 86

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

Answer 86

percussion Inspection involves looking at the patient and is useful when identifying edema, skin lesions, asymmetry, etc. Palpation uses a light finger touch and is used to identify lymphadenopathy, inflammation, presence of inflamed nodes, etc. Auscultation involves listening to sounds in the body, such as the heart, lungs and bowels.

Question 87

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

Answer 87

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

Question 88

The annual occupational effective dose limits recommended by NCRP is ________. 5 mSv 50 mSv 5 Sv 50 Sv

Answer 88

50 mSv NCRP established an annual effective dose limit of 50 mSv for occupationally exposed personnel.

Question 89

Intravenous contrast media can be toxic to the: Heart Arteries Kidneys Bladder

Answer 89

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

Question 90

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

Answer 90

fomite This type of transmission involves inanimate objects that can become contaminated with infectious agents and serve as a mechanism for transfer between hosts.

Question 91

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

Answer 91

localization Verification images document that the treatment portals and patient positioning compare to the reference treatment area for accurate treatment. This is typically done prior to initial treatment and throughout the course of treatment as prescribed by the radiation oncologist.

Question 92

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

Answer 92

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

Question 93

The carina is located at the level of which vertebral bodies? T1-T2 T2-T3 T3-T4 T4-T5

Answer 93

T4-T5 The carina is the bifurcation of the trachea at the level of T4-T5. This is where the right and left main bronchi branch, which is a common location for reference mark placement during lung CT simulation.

Question 94

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

Answer 94

11.2 x 11.2 To solve, the area of open area must be found, then the area of blocked area. Subtract the difference and square root the answer.

Question 95

Which of the following circulating blood cells is MOST resistant to radiation? Erythroblasts Lymphocytes Monocytes Platelets

Answer 95

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

Question 96

________ interactions result in the highest exposure to the patient. Compton and photoelectric Photoelectric and coherent Coherent and Compton Compton and classical

Answer 96

Compton and photoelectric Compton and photoelectric interactions both result in ionization of atoms. When atoms are ionized, energy is imparted. Coherent (classical) interactions do not ionize atoms; therefore, no energy is given up. Therefore, Compton and photoelectric interactions result in the highest exposure to the patient.