MDCB PRACTICE QUESTIONS NEED
EXTRA REVIEW QUESTIONS AND
ANSWERS
A patient is to receive 55 Gy to a tumor in the mediastinum. In order to meet the
acceptable dose limits for the spinal cord, you could:
a. use high energy photon beams to decrease the entrance dose.
b. block the spinal cord out of all treatment fields after 40 Gy is delivered.
c. use a BID treatment technique to achieve greater repair time for the normal tissue
cells.
d. utilize a 3DCRT beam arrangement including oblique beam angles. - ANSWER-d.
utilize a 3DCRT beam arrangement including oblique beam angles.
The cGy as a unit of absorbed dose:
a. is equal to 100 J/kg.
b. only applies in water.
c. may also be used as a unit for KERMA.
d. is only defined for photon beams. - ANSWER-c. may also be used as a unit for
KERMA.
The accuracy of a DVH depends on which of the following?
a. Normal Tissue Complication Probability Value
b. number of OARs assessed
c. Biological Equivalent Dose
d. bin size of histogram - ANSWER-d. bin size of histogram
The process of creating beam intensity profiles to meet the goals of a treatment plan is
called:
a. fluence mapping
b. 3D conformal radiotherapy
c. 4D treatment planning
d. intensity modulation - ANSWER-d. intensity modulation
Which of the following statements are true for Iodine-125?
a. half-life 86.4 days.
b. has life-long radiation protection issues.
c. energy of 0.412 MeV.
d. decays exclusively by electron capture. - ANSWER-d. decays exclusively by electron
capture.
The most significant effect(s) of an air cavity in a megavoltage beam treatment is:
a. a change in the spectral energy distribution within the cavity.
, b. an increased primary photon transmission through the cavity.
c. an enhanced absorption of dose in and beyond the cavity.
d. a partial gain of electronic equilibrium at the cavity interface. - ANSWER-b. an
increased primary photon transmission through the cavity.
For patients with limited life expectancy the common dose fractionation for cord
compression is:
a. 800cGy in 1 fraction.
b. 2000cGy in 5 fractions.
c. 3000cGy in 10 fractions.
d. 3750cGy in 15 fractions. - ANSWER-a. 800cGy in 1 fraction.
Mayneord F factor corrects PDD for:
a. heterogeneity.
b. scatter.
c. Inverse square.
d. exponential attenuation. - ANSWER-b. Inverse square- does not correct for scatter
For quality assurance of brachytherapy treatment planning computers, the dose rates
should agree with published data tables to which of the following degrees?
a. +- 1%
b. +- 2%
c. +- 3%
d. +- 5% - ANSWER-b. +- 2%
Which of the following is an Internet standard that permits uploading and downloading
of data sets with other computers on the Internet?
a. hypertext transfer protocol (http)
b. transfer server protocol (TSP)
c. distant map protocol (DMP)
d. file transfer protocol (FTP) - ANSWER-d. file transfer protocol (FTP)
Mayneord F factor corrects for:
a. PDD.
b. scatter.
c. inverse square.
d. exponential attenuation - ANSWER-a. PDD.
The minimum dose required to produce a cataract in a single radiation exposure is
approximately:
a. 10 cGy.
b. 50 cGy.
c. 200 cGy.
d. 500 cGy. - ANSWER-c. 200 cGy.
EXTRA REVIEW QUESTIONS AND
ANSWERS
A patient is to receive 55 Gy to a tumor in the mediastinum. In order to meet the
acceptable dose limits for the spinal cord, you could:
a. use high energy photon beams to decrease the entrance dose.
b. block the spinal cord out of all treatment fields after 40 Gy is delivered.
c. use a BID treatment technique to achieve greater repair time for the normal tissue
cells.
d. utilize a 3DCRT beam arrangement including oblique beam angles. - ANSWER-d.
utilize a 3DCRT beam arrangement including oblique beam angles.
The cGy as a unit of absorbed dose:
a. is equal to 100 J/kg.
b. only applies in water.
c. may also be used as a unit for KERMA.
d. is only defined for photon beams. - ANSWER-c. may also be used as a unit for
KERMA.
The accuracy of a DVH depends on which of the following?
a. Normal Tissue Complication Probability Value
b. number of OARs assessed
c. Biological Equivalent Dose
d. bin size of histogram - ANSWER-d. bin size of histogram
The process of creating beam intensity profiles to meet the goals of a treatment plan is
called:
a. fluence mapping
b. 3D conformal radiotherapy
c. 4D treatment planning
d. intensity modulation - ANSWER-d. intensity modulation
Which of the following statements are true for Iodine-125?
a. half-life 86.4 days.
b. has life-long radiation protection issues.
c. energy of 0.412 MeV.
d. decays exclusively by electron capture. - ANSWER-d. decays exclusively by electron
capture.
The most significant effect(s) of an air cavity in a megavoltage beam treatment is:
a. a change in the spectral energy distribution within the cavity.
, b. an increased primary photon transmission through the cavity.
c. an enhanced absorption of dose in and beyond the cavity.
d. a partial gain of electronic equilibrium at the cavity interface. - ANSWER-b. an
increased primary photon transmission through the cavity.
For patients with limited life expectancy the common dose fractionation for cord
compression is:
a. 800cGy in 1 fraction.
b. 2000cGy in 5 fractions.
c. 3000cGy in 10 fractions.
d. 3750cGy in 15 fractions. - ANSWER-a. 800cGy in 1 fraction.
Mayneord F factor corrects PDD for:
a. heterogeneity.
b. scatter.
c. Inverse square.
d. exponential attenuation. - ANSWER-b. Inverse square- does not correct for scatter
For quality assurance of brachytherapy treatment planning computers, the dose rates
should agree with published data tables to which of the following degrees?
a. +- 1%
b. +- 2%
c. +- 3%
d. +- 5% - ANSWER-b. +- 2%
Which of the following is an Internet standard that permits uploading and downloading
of data sets with other computers on the Internet?
a. hypertext transfer protocol (http)
b. transfer server protocol (TSP)
c. distant map protocol (DMP)
d. file transfer protocol (FTP) - ANSWER-d. file transfer protocol (FTP)
Mayneord F factor corrects for:
a. PDD.
b. scatter.
c. inverse square.
d. exponential attenuation - ANSWER-a. PDD.
The minimum dose required to produce a cataract in a single radiation exposure is
approximately:
a. 10 cGy.
b. 50 cGy.
c. 200 cGy.
d. 500 cGy. - ANSWER-c. 200 cGy.
