Pre-Mock Exam Part 1

90. The output of a combat-60 teletherapy unit is 85 cGy/ min in air at 80.5 cm for an 11x11 field. The backscatter factor for this field is 1.10. Calculate the time necessary to deliver a dose of 170 cGy at a depth of 8 cm, 80 SSD. The PDD for an 11x11 field at a depth of 8 cm is 63%

2.89 min

78. What is the TD 5/5 tolerance dose for the whole kidney given in fractions of 180 cGY/day?

2000-2500 cGY

83. RBE is dependent on which of the following 1. Radiation quality 2. Radiation dose per fraction 3. Tissue irradiated

1,2,3

50. A patient is to receive 300 cGy per day on a cobalt-60 unit through a single posterior field. The dose rate in air at 80cm is 105.3 cGy/min and the BSF is 1.029. The PDD is 87.5%. Find the treatment time to deliver the prescribed dose.

3 min 10 sec

71. When performing a CT on a patient for IMRT treatment of a prostate, what size slices are used through the true pelvis?

3 mm

54. A 3.5 cm block on a blocking tray 45 cm from the source will block what width at 100 cm? a. 4.80 cm b. 5.20 cm c. 6.01 cm d. 7.78 cm

7.78 cm

88. A patient thickeness is measured to be 20 cm anterior to posterior. If the patient is brought to an SSD of 90 cm on a 100 cm SAD accelerator, what should a ruler read from the tabletop to isocenter? Assume the patient is flat on the table.

10 cm

92. Assume a half value layer of PB = 3 MM. How thick would the lead have to be to reduce exposure of one MR at 4 meters to 100 MR at 1 m?

12 mm

53. The depth of maximum dose is most dependent on: a. SSD b. field size c. beam energy d. thickness of tissue

Beam energy

31. When treating a patient with cancer of the tongue, what is the purpose of putting a bite block (tongue gag) in the patients mouth?

Flatten tongue

9. The epiglottis is a flap of cartilage that folds back to cover the entrance of the:

larynx

24. Where is the spleen located?

left upper quadrant

21. When treating the entire CNS axis, the bottom of the spin port generally extends to the level of ____ when encompassing the cauda equina.

S-2

56. Find the equivalent square of the resultant field of a 12 x 12 field with a 4 x 6 block.

11 x 11

10. Hypofractionation is: 1. Treatment given in fewer fractions than standard 2. Use of very low dose rates 3. Treatment given two or more times per day

1 only

75. When manipulating a CT image, increasing the width of the window: 1. Decreases contrast 2. Increases latitude 3. Increases speed

1&2

44. Which of the following areas are generally encompassed in a "German helmet" radiation port when treating acute lymphocytic leukemia? 1. Cribiform plate 2. Meninges 3. Posterior retina

1, 2 & 3

51. A patient is usually treated at 100cm SSD. The patient must be treated on a stretcher at 135 SSD. For the tumor dose and size treatment area to remain the same as originally planned, which of the following statements is true? 1. The Collimator setting will decrease 2. The monitor unit setting will increase 3. The exit dose will slightly increase

1, 2 & 3

5. Breast cancer metastasizes to: 1. Bone 2. Lung 3. Brain

1, 2, 3

89. Which of the following is required for fabricating custom cut blocks?

1. Source axis distance 2. Source image distance 3. Source to block tray distance

61. What is the therapeutic ratio if the normal tissue tolerance is 5000 cGy and the lethal dose for the tumor is 4000?

1.25

49. What fraction would you multiply an electron energy by to estimate the 90% Isodose range?

1/4

34. What is the TD 5/5 tolerance dose using standard fractionation, for the lens of the eye?

1000 cGy or 10 Gy

63. A treatment of 137 monitor units requires that a blocking tray factor of 0.963 be included in the calculation. What are the correct treatment monitor units if the tray is added? a. 132 mu b. 137 mu c. 142 mu d. 150 mu

142 mu

85. A patient was treated with a 20 cm long field and a 15 cm long field is matched to it. Both fields are set at 80 cm SSD. What is the gap on the skin if the fields are to be matched at 10 cm depth?

2.2 cm

93. A dose of 3000 cGy is delivered to a depth of 8 cm at PDD of 76%. What is the dose to an underlying organ at 14 cm at a PDD of 58%

2289 cGy

52. A dose of 200 cGy is to be delivered at a depth of 10cm at 100 SAD, from a single 15x15 cm field with 6 MV x-rays. Given the information below, what would the treatment monitor units be? TMR (15x15cm, depth 10cm)= .806 Output in air, 100 SAD 15x15 cm field size= 1.015 cGy/min BSF (15x15 cm)= 1.044 PDD (100SSD,15 cm depth=10cm)=72.2%

234 MU

19. The tolerance dose (TD5/5) of the whole liver using standard fractionation (180-200 cGy/day) is:

2500-3000 cGy

99. Calculate the monitor units to deliver 200 cGy to the 90% isodose line using 12 MeV electrons at 100 cm SSD if the measured output for the cone and cutout is .787 cGy/MU at 100 SSD.

282 MU

64. If a patient received a tumor dose of 250 cGy per day at the 79.2% depth dose, what is the daily maximum subcutaneous dose?

316 cGy

100. A patient is receiving 300 cGy per day to a spinal cord lesion at 89.5 percent depth dose. What is the daily given dose at dmax?

335

95. The collimators on a linear accelerator are calibrated for a distance of 100 cm. To obtain a field size of 30 cm x 30 cm at 80 cm, what collimator setting is required?

37.5 cm x 37.5 cm

42. The tolerance dose (TD 5/5) for the whole brain using standard fractionation is approximately:

4500 cGy

87. A patient is treated with a 8x15 cm field, Co-60 unit, 80 cm SSD to a depth of 5 cm, 78.5% depth dose. What would the percentage depth dose be if the SSD was changed to 100 cm?

80.1 %

91. A patient is to be treated isocentrically to his midline on the 6 MV linear accelerator at 100 cm SAD. Calipers have measured the patient thickness to be 21 cm. The patient is positioned flat on the table top. What SSD is required for isocentric treatment to the patient's midline?

89.5 cm

70. The practical range for 18 MeV electron is:

9cm

72. The largest salivary gland on the head and neck is the

Parotid

8. The most common histopathology of endometrial cancer is:

Adenocarinoma

32. What external landmark can be used to locate the carina?

Angle of Louis

26. The collapse of a part of all of the lung, which often results from bronchial obstruction is termed:

Atelectasis

12. With breast cancer which of the following patterns of lymph node drainage occurs most often? A. Internal mammary B. Axillary C. Supraclavicular D. Mediastinal

B. Axillary

1. What cancer is "peau de orange" associated with?

Breast

80. A patient is setup on a wing board with both arms up. What areas are commonly treated using this position?

Breast , lung, pancreas

18. The inguinal lymph nodes are generally included in which of the following treatment sites?

Vulva

4. The lower constricted portion of the uterus is called the:

Cervix

36. The inferior border of a larynx port for a vocal cord carcinoma should anatomically correspond to:

Cricoid cartilage

67. The most common presentation of superior vena cava syndrome is:

Distended veins in the head and neck

73. For patients with bladder cancer, the bladder should be _____ during treatment, when the entire bladder is the target volume.

Empty

27. When treating the maxillary antrum, which neighboring structuring is most sensitive?

Eye

39. The patients chin is tilted down when treating a pituitary gland to avoid the:

Eye

81. What normal organ would be at most risk when treating a maxillary sinus tumor?

Eye

15. Referring to the CT scan below, the arrow is pointing to the: AKidney BStomach CGallbladder DSpleen

Gallbladder

20. The degree of cellular differentiation and rate of tumor growth is the:

Grade

58. Areas outside the target that receives a higher dose than the specified target dose are called: a. max target area b. irradiated volume c. hot spots d. treated volume

Hot spots

37. The vallecula is located at the level of which of the following anatomical structures? A.Pyriform sinus B.Thyroid cartilage C.Hyoid bone D.Cricoid cartilage

Hyoid bone

33. If a patient has a reaction to contrast media, you would expect to see all of the following EXCEPT:

Incontinence

6. In the normal adult male the prostate is located ____ to the bladder.

Inferior

35. If you are using a gonad shield when treating a patient with a seminoma on a 6 MV linear accelerator, why can't all of the scatter to the testicles be eliminated?

Internal scatter from the patient cannot be eliminated

23. The common iliac nodes are generally found around the level of:

L5

77. The amount of energy transferred to a material per unit length of travel is termed:

LET

3. The vocal cords are found within a structure formed by cartilage called the:

Larynx

40. What is the technique in which a skin cancer is removed and examined one layer at a time?

Mohs surgery

97. When treating the breast, if a slant board is used rather than the patient lying flat, which of the following is true?

More lung tissue is included in the supraclavicular port

46. A non-Osseous tumor of the bone marrow is the:

Multiple Myeloma

14. If a pathology report indicates a stage of T1N0M3, what can be said about the lymph node involvement of the nodes sampled? A. Positive nodes are found close to the primary tumor B. The nodes were unable to be sampled C. No positive nodes were present D. Positive nodes are found at distant sites

No positive nodes were present

79. What is the most potent chemical modifier of radiosensitivity to C and gamma rays?

Oxygen

17. Nasopharyngeal tumors drain through what lymph node group first?

Posterior cervical

82. When dealing with OER and anoxic tissue, which would be the most effective?

Protons

43. A strontium-90 applicator may be useful in the treatment of which of the following diseases of the eye?

Pterygium

30. When treating a breast patient, the slope of the sternal notch to the xiphoid could be corrected by:

Slant board

41. What type of lung cancer has the highest incidence of metastases at presentation?

Small cell

45. Which of the following is the MOST radiosensitive structure?

Spine

7. The largest lymphoid tissue is the:

Spleen

47. The false vocal cords are located_______ to the glottis

Superior

29. The trachea bifurcates at the level of:

T4-T5

38. The xiphoid is located at the level of: A. T4-T5 B. T7-T8 C. T9-T10 D. T11-T12

T9-T10

22. When treating the entire CNS axis, the bottom of the spine port generally extends to the level of _______ when encompassing the cauda equina.

Temporal lobes

48. What is the primary reason to angle the gantry posteriorly when treating Grave's disease with two lateral fields?

To avoid divergence into the lens

13. Which of the following is the most common site for a spinal cord compression?

Thoracic

25. What external landmark can be used to localize the top of the larynx? A. Thyroid prominence B. Hyoid bone C. Cervical vertebrae D. Waldyer's ring

Thyroid prominence

94. When treating a lesion on the outside of the nose with electrons, what is the major reason that you place a wax coated ledge strip on the nose?

To decrease the dose to the inside of the nose

86. When a patient has been treated with a cesium insertion for cervical cancer, why would she be treated with external beam radiation following the cesium?

To treat the pelvic lymph nodes

16. The most common type of breast cancer is:

infiltrating ductal

11. The most common site for metastatic spread of carcinoma of the penis is the:

inguinal nodes

2. What type of lung cancer may need prophylactic brain irradiation?

small cell