MDCB practice questions need extra

MDCB practice questions need extra review Questions with Complete Solutions (Latest 2025) 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:

• use high energy photon beams to decrease the entrance

dose.

• block the spinal cord out of all treatment fields after 40 Gy

is delivered.

• use a BID treatment technique to achieve greater repair

time for the normal tissue cells.

• utilize a 3DCRT beam arrangement including oblique beam

angles. - Correct Answers ✅d. utilize a 3DCRT beam arrangement including oblique beam angles.Which of the following statements are true for Iodine-125?

• half-life 86.4 days.
• has life-long radiation protection issues.
• energy of 0.412 MeV.
• decays exclusively by electron capture. - Correct

Answers ✅d. decays exclusively by electron capture.The most significant effect(s) of an air cavity in a

megavoltage beam treatment is:

• a change in the spectral energy distribution within the

cavity. 1 / 3

MDCB practice questions need extra review Questions with Complete Solutions (Latest 2025)

• an increased primary photon transmission through the

cavity.

• an enhanced absorption of dose in and beyond the cavity.
• a partial gain of electronic equilibrium at the cavity

interface. - Correct Answers ✅b. an increased primary photon transmission through the cavity.For patients with limited life expectancy the common dose

fractionation for cord compression is:

• 800cGy in 1 fraction.
• 2000cGy in 5 fractions.
• 3000cGy in 10 fractions.
• 3750cGy in 15 fractions. - Correct Answers ✅a. 800cGy

in 1 fraction.

Mayneord F factor corrects PDD for:

• heterogeneity.
• scatter.
• Inverse square.
• exponential attenuation. - Correct Answers ✅b. Inverse

square- does not correct for scatter 2 / 3

MDCB practice questions need extra review Questions with Complete Solutions (Latest 2025) For quality assurance of brachytherapy treatment planning computers, the dose rates should agree with published data tables to which of the following degrees?

• +- 1%
• +- 2%
• +- 3%
• +- 5% - Correct Answers ✅b. +- 2%

The expected accuracy of treatment planning systems that

perform brachytherapy dose calculations should be within: a.

+/- 3%

• +/- 5%
• +/- 7%
• +/- 10% - Correct Answers ✅b. +/- 5%

With LINAC based SBRT/SABR and a plan that has a 100% maximum IDL, what is the typical range of prescription isodose line covering the PTV?

• 40 - 60 %
• 60 - 90 %
• 90 - 100 %
• > 100 % - Correct Answers ✅c. 90 - 100 %
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