MDCB EXAM QUESTIONS AND ANSWERS. A+ GRADED
GUIDE.
Although they receive the same dose, some tissues exhibit acute radiation damage earlier than others
because they have a:
A. smaller number of metabolizing cells.
B. reduced blood flow.
C. lower number of hypoxic cells.
D. higher mitotic index.
D. higher mitotic index.
Unless otherwise permitted by the NRC, brachytherapy needles and tubes must be leak tested by the
user at intervals NOT to exceed:
A. 1 month.
B. 3 months.
C. 6 months.
D. 9 months.
C. 6 months (Semiannually)
Concerning the precision of treatment planning and delivery of treatment in radiation therapy, the
greatest source of uncertainty is:
A. the histology of the disease.
B. physical response data.
C. patient and organ motion during treatment.
D. linear accelerator calibration.
C. patient and organ motion during treatment.
In SRS, a localizer is attached to the head ring for the primary purpose to:
A. reduce the movement of head during simulation and treatment.
B. transform the CT coordinate system to stereotactic coordinate system.
C. position the patient at the treatment beam isocenter.
D. register the CT and MRI images.
B. transform the CT coordinate system to stereotactic coordinate system.
Which of the following factors results in an increase in the percent depth dose (PDD) of a megavoltage
beam?
A. increase the source-to-skin distance
B. decrease in source-to-skin distance
C. decrease in field size
D. increase in dose rate
A. increase the source-to-skin distance
, Bolus is often used in electron beam therapy to do which of the following?
A. to increase mean energy of a given electron beam
B. to increase beam flatness and symmetry
C. reduce the penetration of the electrons in parts of the field
D. reduce the amount of scatter due to inhomogeneities
C. reduce the penetration of the electrons in parts of the field
The primary purpose of using a planning target volume (PTV) in treatment planning is to:
A. extend the CTV to include any microscopic disease surrounding the GTV.
B. include any internal margin (IM) around the CTV.
C. include the imaging artifacts in delineation of the CTV.
D. ensure that the CTV will receive the prescribed dose.
D. ensure that the CTV will receive the prescribed dose.
The contrast resolution for a treatment planning CT scan can be described as a:
A. function of scanner geometry, including focal spot size, field of view and detector size.
B. function of the electron density and the atomic number of the tissue within a pixel.
C. measure of the modulation transfer function and the algorithm characteristics.
D. measure of the ability to detect objects with small differences in Hounsfield units.
D. measure of the ability to detect objects with small differences in Hounsfield units.
In patients with locally-advanced NSCLC treated with concurrent chemoradiotherapy, what is the
most common morbidity?
A. pneumonitis
B. esophagitis
C. pericarditis
D. transverse myelitis
B. esophagitis
The dose to which of these areas would be of the least dosimetric concern when using an electron
beam for total skin irradiation?
A. soles of the feet
B. finger nails
C. scalp
D. lungs
D. lungs
When simulating tangential fields to treat a breast tumor, including the internal mammary nodes, the
medial field edge is set 3 cm to the contralateral side and the lateral field edge is set to encompass all
of the breast tissue. If too much lung is traversed by these fields, a correction may be made by doing
which of the following?
A. moving the medial field edge toward the contralateral side
B. moving the lateral field edge posteriorly
GUIDE.
Although they receive the same dose, some tissues exhibit acute radiation damage earlier than others
because they have a:
A. smaller number of metabolizing cells.
B. reduced blood flow.
C. lower number of hypoxic cells.
D. higher mitotic index.
D. higher mitotic index.
Unless otherwise permitted by the NRC, brachytherapy needles and tubes must be leak tested by the
user at intervals NOT to exceed:
A. 1 month.
B. 3 months.
C. 6 months.
D. 9 months.
C. 6 months (Semiannually)
Concerning the precision of treatment planning and delivery of treatment in radiation therapy, the
greatest source of uncertainty is:
A. the histology of the disease.
B. physical response data.
C. patient and organ motion during treatment.
D. linear accelerator calibration.
C. patient and organ motion during treatment.
In SRS, a localizer is attached to the head ring for the primary purpose to:
A. reduce the movement of head during simulation and treatment.
B. transform the CT coordinate system to stereotactic coordinate system.
C. position the patient at the treatment beam isocenter.
D. register the CT and MRI images.
B. transform the CT coordinate system to stereotactic coordinate system.
Which of the following factors results in an increase in the percent depth dose (PDD) of a megavoltage
beam?
A. increase the source-to-skin distance
B. decrease in source-to-skin distance
C. decrease in field size
D. increase in dose rate
A. increase the source-to-skin distance
, Bolus is often used in electron beam therapy to do which of the following?
A. to increase mean energy of a given electron beam
B. to increase beam flatness and symmetry
C. reduce the penetration of the electrons in parts of the field
D. reduce the amount of scatter due to inhomogeneities
C. reduce the penetration of the electrons in parts of the field
The primary purpose of using a planning target volume (PTV) in treatment planning is to:
A. extend the CTV to include any microscopic disease surrounding the GTV.
B. include any internal margin (IM) around the CTV.
C. include the imaging artifacts in delineation of the CTV.
D. ensure that the CTV will receive the prescribed dose.
D. ensure that the CTV will receive the prescribed dose.
The contrast resolution for a treatment planning CT scan can be described as a:
A. function of scanner geometry, including focal spot size, field of view and detector size.
B. function of the electron density and the atomic number of the tissue within a pixel.
C. measure of the modulation transfer function and the algorithm characteristics.
D. measure of the ability to detect objects with small differences in Hounsfield units.
D. measure of the ability to detect objects with small differences in Hounsfield units.
In patients with locally-advanced NSCLC treated with concurrent chemoradiotherapy, what is the
most common morbidity?
A. pneumonitis
B. esophagitis
C. pericarditis
D. transverse myelitis
B. esophagitis
The dose to which of these areas would be of the least dosimetric concern when using an electron
beam for total skin irradiation?
A. soles of the feet
B. finger nails
C. scalp
D. lungs
D. lungs
When simulating tangential fields to treat a breast tumor, including the internal mammary nodes, the
medial field edge is set 3 cm to the contralateral side and the lateral field edge is set to encompass all
of the breast tissue. If too much lung is traversed by these fields, a correction may be made by doing
which of the following?
A. moving the medial field edge toward the contralateral side
B. moving the lateral field edge posteriorly
