MDCB Practice Set 1 - Test 2 questions with verified
answers
10. The most important prognostic factor in breast cancer is the:
A. size of the tumor.
B. age of the patient.
C. status of the axillary nodes.
D. quadrant of origin within the breast. Ans✓✓✓ C
11. A dose of 30 Gy in 10 fractions to a depth of 7 cm from a 6 MV
single posterior field using an
isocentric technique at 100 cm source-to-axis distance (SAD). The
patient was incorrectly
treated five times at 100 cm source-to-surface distance (SSD). The
approximate dose at 7 cm
after five fractions is:
A. 11.6 Gy.
B. 13.1 Gy.
C. 13.8 Gy.
D. 15.0 Gy. Ans✓✓✓ B
12. Electron beam output factors are corrected for by using which of
the following?
A. energy coefficient
, B. equivalent thickness
C. virtual source distance
D. electron range Ans✓✓✓ C
13. Electron arc therapy is most useful for treating tumors of the:
A. pituitary.
B. chest wall.
C. pancreas.
D. brain. Ans✓✓✓ B
14. Percentage Depth Dose is dependent on which of the following?
A. Field size
B. Tissue density
C. Treatment time
D. Dose rate Ans✓✓✓ A
15. Where is dose routinely normalized when using a fixed Source to
Surface Distance (SSD) technique?
A. At isocenter
B. A tumor depth
C. At Dmax
D. On the surface Ans✓✓✓ C
answers
10. The most important prognostic factor in breast cancer is the:
A. size of the tumor.
B. age of the patient.
C. status of the axillary nodes.
D. quadrant of origin within the breast. Ans✓✓✓ C
11. A dose of 30 Gy in 10 fractions to a depth of 7 cm from a 6 MV
single posterior field using an
isocentric technique at 100 cm source-to-axis distance (SAD). The
patient was incorrectly
treated five times at 100 cm source-to-surface distance (SSD). The
approximate dose at 7 cm
after five fractions is:
A. 11.6 Gy.
B. 13.1 Gy.
C. 13.8 Gy.
D. 15.0 Gy. Ans✓✓✓ B
12. Electron beam output factors are corrected for by using which of
the following?
A. energy coefficient
, B. equivalent thickness
C. virtual source distance
D. electron range Ans✓✓✓ C
13. Electron arc therapy is most useful for treating tumors of the:
A. pituitary.
B. chest wall.
C. pancreas.
D. brain. Ans✓✓✓ B
14. Percentage Depth Dose is dependent on which of the following?
A. Field size
B. Tissue density
C. Treatment time
D. Dose rate Ans✓✓✓ A
15. Where is dose routinely normalized when using a fixed Source to
Surface Distance (SSD) technique?
A. At isocenter
B. A tumor depth
C. At Dmax
D. On the surface Ans✓✓✓ C
