Pr actice Exam 4 Ration ale
1. The electron gun and accelerator structure are located in the gantry. The klystron
is in the drive stand and the bending magnet is in the treatment head.
2. The image is a 3-field pelvis in the prone position. The fields are PA, left lateral
and right lateral. Look at the higher isodose lines to visualize entrance dose
(blue). The tan and brown isodose lines are low doses and visualize exit dose.
3. Hoyer lifts are mechanical devices that allows healthcare professionals to lift
patients with minimal physical effort. A sling is placed under the patient to hold
and support the patient. The sling attaches to the Hoyer lift to allow for vertical
movement.
4. Letter “D” represents the treatment head, where the ion chambers are located.
5. The order of machine parts for photon beam treatments = target, primary
collimators, flattening filter, ion chamber, secondary collimators, MLCs. When an
electron beam is needed, the target and flattening filter are removed. Instead of
the flattening filter, we see the scattering foil.
6. The Food and Drug Administration (FDA) regulates the manufacturing of linacs.
7. This image is of a half-beam block technique. This is also known as a
monoisocentric 3 field breast. The isocenter is placed between the tangent breast
fields and the supraclavicular field. This image shows the supraclavicular field.
The inferior jaw is closed to 0 to avoid beam divergence.
8. Epidemiology = the study how many people have a disease.
9. Flattening filters are made of high z# (atomic number) materials, in a cone shape
(with the thicker section in the center) and helps to reduce the intensity in the
center of the beam in efforts to make it more uniform or homogenous.
10. PDD is affected by energy, depth, field size, and SSD.
11. The U.S. Nuclear Regulatory Commission protects the public against radioactive
materials.
12. The electron gun is located in the gantry, denoted by the letter C.
, 13. Tumor motion can be reduced using DIBH, gating, and abdominal compression
techniques. 4D CTs do not reduce tumor motion, but rather track the motion
during the scan to show the full motion of the tumor on all breathing phases.
14. Colon, eye retina and brain have a tolerance dose of 4500 cGy for the whole
organ. The heart has a tolerance dose of 4000 cGy for the whole organ.
15. Colorectal cancer has multiple screening tests: colonoscopy, sigmoidoscopy, and
stool tests (fecal occult blood tests and stool DNA tests).
16. The treatment field shown is a hockey-stick technique that is used to treat
seminomas.
17. A radiopaque structure appears white on a radiograph. In this photo, #3
represents the vertebral body and appears white.
18. Tumor grade is determined by examining how a cell looks under a microscope. If
it resembles normal cells, it is said to be “well-differentiated” and less aggressive.
If it does not resemble normal cells, it is “undifferentiated” and is more
aggressive.
19. The drive stand contains the klystron and circulator. The power supply is a
separate component. The accelerator structure is located in the gantry.
20. The occupational exposure limits are 10x than public exposure limits.
21. Xerostomia can occur once the parotid gland exceeds its tolerance dose of 3200
cGy to 3/3 of the organ.
22. There are specific rules to be followed for sterile techniques. Sterile fields occur at
the level of the tabletop and waist level and up (below this level is not sterile). No
one should lean over the sterile field. Once sterile item becomes wet, it is no
longer sterile. Contact between sterile objects and non-sterile objects should be
avoided. When two sterile people are passing each other, they must pass back-to-
back.
23. Axial images allow matching to occur in the anterior and posterior direction as
well as the left to right direction. The superior and inferior directions are not
visualized on an axial image.
1. The electron gun and accelerator structure are located in the gantry. The klystron
is in the drive stand and the bending magnet is in the treatment head.
2. The image is a 3-field pelvis in the prone position. The fields are PA, left lateral
and right lateral. Look at the higher isodose lines to visualize entrance dose
(blue). The tan and brown isodose lines are low doses and visualize exit dose.
3. Hoyer lifts are mechanical devices that allows healthcare professionals to lift
patients with minimal physical effort. A sling is placed under the patient to hold
and support the patient. The sling attaches to the Hoyer lift to allow for vertical
movement.
4. Letter “D” represents the treatment head, where the ion chambers are located.
5. The order of machine parts for photon beam treatments = target, primary
collimators, flattening filter, ion chamber, secondary collimators, MLCs. When an
electron beam is needed, the target and flattening filter are removed. Instead of
the flattening filter, we see the scattering foil.
6. The Food and Drug Administration (FDA) regulates the manufacturing of linacs.
7. This image is of a half-beam block technique. This is also known as a
monoisocentric 3 field breast. The isocenter is placed between the tangent breast
fields and the supraclavicular field. This image shows the supraclavicular field.
The inferior jaw is closed to 0 to avoid beam divergence.
8. Epidemiology = the study how many people have a disease.
9. Flattening filters are made of high z# (atomic number) materials, in a cone shape
(with the thicker section in the center) and helps to reduce the intensity in the
center of the beam in efforts to make it more uniform or homogenous.
10. PDD is affected by energy, depth, field size, and SSD.
11. The U.S. Nuclear Regulatory Commission protects the public against radioactive
materials.
12. The electron gun is located in the gantry, denoted by the letter C.
, 13. Tumor motion can be reduced using DIBH, gating, and abdominal compression
techniques. 4D CTs do not reduce tumor motion, but rather track the motion
during the scan to show the full motion of the tumor on all breathing phases.
14. Colon, eye retina and brain have a tolerance dose of 4500 cGy for the whole
organ. The heart has a tolerance dose of 4000 cGy for the whole organ.
15. Colorectal cancer has multiple screening tests: colonoscopy, sigmoidoscopy, and
stool tests (fecal occult blood tests and stool DNA tests).
16. The treatment field shown is a hockey-stick technique that is used to treat
seminomas.
17. A radiopaque structure appears white on a radiograph. In this photo, #3
represents the vertebral body and appears white.
18. Tumor grade is determined by examining how a cell looks under a microscope. If
it resembles normal cells, it is said to be “well-differentiated” and less aggressive.
If it does not resemble normal cells, it is “undifferentiated” and is more
aggressive.
19. The drive stand contains the klystron and circulator. The power supply is a
separate component. The accelerator structure is located in the gantry.
20. The occupational exposure limits are 10x than public exposure limits.
21. Xerostomia can occur once the parotid gland exceeds its tolerance dose of 3200
cGy to 3/3 of the organ.
22. There are specific rules to be followed for sterile techniques. Sterile fields occur at
the level of the tabletop and waist level and up (below this level is not sterile). No
one should lean over the sterile field. Once sterile item becomes wet, it is no
longer sterile. Contact between sterile objects and non-sterile objects should be
avoided. When two sterile people are passing each other, they must pass back-to-
back.
23. Axial images allow matching to occur in the anterior and posterior direction as
well as the left to right direction. The superior and inferior directions are not
visualized on an axial image.
