1. What are the four “R’s” of external beam radiation?

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a. rep_____

repair

b. reo_____

reoxygenation

c. repop_____

repopulation

d. red_____

redistribution

2. Complete the following about cranial radiation:

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a. After surgery most surgerons wait_____to_____ days.

7 to 10

b. Tumors that melt away with XRT are

     i. l_____

lymphomas

     ii. g_____c_____

germ cell

3. True or False. Regarding radiation necrosis (RN):

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a. RN is easy to differentiate from tumor recurrence.

false

b. Best test to differentiate is

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     i. MR spectroscopy if mass is pure tumor

true

     ii. MR spectroscopy if mass is pure necrosis

true

     iii. MR spectroscopy if mass is mixed

false(unreliable)

     iv. SPECT (poor man’s pet scan)

true

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c. Treatment

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     i. Most RN will respond to steroids.

true

     ii. Mass effect dictates advisability of surgery whether RN or recurrent tumor.

true

4. Spinal radiation

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a. can produce_____.

myelopathy

b. can increase risk of developing spinal _____ _____.

cavernous malformation

5. Complete the following about radiation myelopathy (RM):

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a. Most important factor is rate of radiation _____.

application

b. Second is total_____ _____.

radiation dose

6. Is stereotactic radiosurgery (SRS) useful for:

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a. venous angiomas?

no

b. cavernous angiomas?

no

7. Complete the following about stereotactic radiosurgery:

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a. For most cases what is the optimal treatment for vestibular schwannoma?

surgery

b. What alternative is available?

SRS

c. When would the alternative for the patient be considered?

     i. p_____m_____c_____

poor medical condition

     ii. o_____a_____g_____

older age group

8. Answer the following about stereotactic radiosurgery:

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a. Accuracy is never better than_____.

0.6 mm

b. If embolization is used what precaution is advised before SRS?

wait 30 days between procedures

c. What dose is optimal for an arteriovenous malformation (AVM)?

10 to 15 Gy to periphery of AVM

d. What dose is optimal for tumors?

10 to 15 Gy with tumor in the 80% isodose line

e. What dose is optimal for metastatic tumors?

15 Gy to center of tumor in the 80% isodose line

9. Complete the following regarding the results, in percent, of SRS obliteration of:

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a. AVM

     i. AVM at 1 year_____

46 to 61%

     ii. AVM at 2 years_____

86%

     iii. under 2 cm_____

94%

     iv. over 2.5 cm_____

50%

b. acoustic tumor

     i. decreased in size_____

44%

     ii. stabilized in size_____

42%

     iii. increased in size_____

14%

c. local metastatic control_____

88%

10. What is advised if, after SRS, an AVM persists after 2 to 3 years?

may re-treat with SRS

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11. Is there any difference in outcome with SRS by radio-resistant versus radio-sensitive tumors?

no

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12. Which has a better response, supra- or infratentorial metastases?

supratentorial

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13. Which premedication is given before SRS?

steroids and phenobarbital

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14. During the latency period is there a higher incidence of hemorrhage from AVM?

no, approximately 3 to 4% per year

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15. Answer the following about interstitial brachytherapy:

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a. How much radiation is given?

60 Gy

b. To what area?

a volume that extends 1 cm beyond the contrast-enhancing tumor

c. At what rate?

40 to 50 c Gy/h

d. For how many days?

6

e. What is the radiation amount that will cause tumor growth to stop?

30 c Gy/h

f. With this protocol what percent of patients develop symptomatic radiation necrosis?

40%