Mdcb Exam Actual Questions and
Answers 2026
For a 4-fld box techn, which of the following will deliver the lower
dose to the femoral heads? -
correct answer ✅100 SSD, equal dmax dose to all fields
SSD= less hot spots
Which of the following can be classified as indirectly ionizing
radiaiton? -
correct answer ✅Photons
Also neutrons, x-ray and gamma rays
The presence of a shoulder on the survival curve of most
mammalian cells indicates which of the following? -
correct answer ✅a reduced efficiency of cell killing at low doses
When opposing lateral fields to the pharynx are abutted at midline
to the anterior field to the suproclavicular fossae, overdose in the
cord may be avoided by -
correct answer ✅a small block over the cord in the inf post corner
of both lateral fields
,Mdcb Exam Actual Questions and
Answers 2026
In Photoelectric interactions -
correct answer ✅the entire energy of the incident photon is
absorbed by the resulting electron
Film badges used for personnel monitoring contain filters that are
used to: -
correct answer ✅fitler info about beam quality and energies
Giving too much radiation to which of the following can lead to
xerostomia -
correct answer ✅base of tongue
The inguinal lymph nodes are located at a depth of -
correct answer ✅2-18 cm from the anterior skin surface and are
dependent on the pt's size
The contrast resolution for a tx planning CT scan can be described
as a -
correct answer ✅measure of the ability to detect objects with
small differences in hounsfield units
,Mdcb Exam Actual Questions and
Answers 2026
a small area of high density near the surface of hte pt would have
the greatest impact on the dose near the edge of the high density
are with: -
correct answer ✅a single 20 MeV electron field
-^energy ^ surface dose
Mass attenuation coefficient depends on the -
correct answer ✅thickness of the material being atttenuated
The binding energy of the nucleus -
correct answer ✅represents a mass defect in the nucleus
-binding energy of nucleus is proportional to the stability of a
nucleus
Accuracy for radiation therapy tx require accuracy within: -
correct answer ✅+/- 3%
daily output +/- 3%
the value for the Ngas calibration factor for an ioniziation chamber
will depend on the: -
correct answer ✅composition of the chamber wall
, Mdcb Exam Actual Questions and
Answers 2026
Which are the following descriptors of characteristic x-rays or
brems radiation is true? -
correct answer ✅Characteristic x-rays are produced following
ionization
-ionization is having enough energy to eject an electron. When it's
ejected then a characteristic x-ray is produced b/c an electron falls
into then empty place
According to AAPM TG report #142, when performing periodic linac
quality assurance procedures, which of the following is the
acceptable tolerance for electron flatness -
correct answer ✅3%
Flatness-3%
an individual receives a dose of 0.1 cGy from a gamma source and
0.05cGy from neutrons. The dose equivalent from both radiation
sources is? -
correct answer ✅0.1x1+0.05x20=1.1cGy =11 mSv
For quality assurance of brachytherapy tx planning computers, the
dose rates should agree with published data tables to which of the
following degrees? -
correct answer ✅+/-2
Answers 2026
For a 4-fld box techn, which of the following will deliver the lower
dose to the femoral heads? -
correct answer ✅100 SSD, equal dmax dose to all fields
SSD= less hot spots
Which of the following can be classified as indirectly ionizing
radiaiton? -
correct answer ✅Photons
Also neutrons, x-ray and gamma rays
The presence of a shoulder on the survival curve of most
mammalian cells indicates which of the following? -
correct answer ✅a reduced efficiency of cell killing at low doses
When opposing lateral fields to the pharynx are abutted at midline
to the anterior field to the suproclavicular fossae, overdose in the
cord may be avoided by -
correct answer ✅a small block over the cord in the inf post corner
of both lateral fields
,Mdcb Exam Actual Questions and
Answers 2026
In Photoelectric interactions -
correct answer ✅the entire energy of the incident photon is
absorbed by the resulting electron
Film badges used for personnel monitoring contain filters that are
used to: -
correct answer ✅fitler info about beam quality and energies
Giving too much radiation to which of the following can lead to
xerostomia -
correct answer ✅base of tongue
The inguinal lymph nodes are located at a depth of -
correct answer ✅2-18 cm from the anterior skin surface and are
dependent on the pt's size
The contrast resolution for a tx planning CT scan can be described
as a -
correct answer ✅measure of the ability to detect objects with
small differences in hounsfield units
,Mdcb Exam Actual Questions and
Answers 2026
a small area of high density near the surface of hte pt would have
the greatest impact on the dose near the edge of the high density
are with: -
correct answer ✅a single 20 MeV electron field
-^energy ^ surface dose
Mass attenuation coefficient depends on the -
correct answer ✅thickness of the material being atttenuated
The binding energy of the nucleus -
correct answer ✅represents a mass defect in the nucleus
-binding energy of nucleus is proportional to the stability of a
nucleus
Accuracy for radiation therapy tx require accuracy within: -
correct answer ✅+/- 3%
daily output +/- 3%
the value for the Ngas calibration factor for an ioniziation chamber
will depend on the: -
correct answer ✅composition of the chamber wall
, Mdcb Exam Actual Questions and
Answers 2026
Which are the following descriptors of characteristic x-rays or
brems radiation is true? -
correct answer ✅Characteristic x-rays are produced following
ionization
-ionization is having enough energy to eject an electron. When it's
ejected then a characteristic x-ray is produced b/c an electron falls
into then empty place
According to AAPM TG report #142, when performing periodic linac
quality assurance procedures, which of the following is the
acceptable tolerance for electron flatness -
correct answer ✅3%
Flatness-3%
an individual receives a dose of 0.1 cGy from a gamma source and
0.05cGy from neutrons. The dose equivalent from both radiation
sources is? -
correct answer ✅0.1x1+0.05x20=1.1cGy =11 mSv
For quality assurance of brachytherapy tx planning computers, the
dose rates should agree with published data tables to which of the
following degrees? -
correct answer ✅+/-2
