Updated by Jennifer Logan

1. What is the cell of origin for vestibular schwannomas and acoustic neuromas (ANs)?  

2. Which CN do ANs affect?  

3. In which anatomic region do ANs arise?  

4. What are the most common presenting Sx, incidence, and what CNs are they associated with?  

5. What is the median age at Dx?  

6. Most people with symptomatic ANs will present b/t what ages?  

7. What proportion of ANs are sporadic?  

8. What % of ANs are bilat, and with what genetic abnormality are they associated?  

9. What protein is abnl in NF-2 pts?  

10. What is the name of the anatomic layer of CN VIII that gives rise to most ANs?  

11. Subclinical ANs are present in what % of the general population?  

12. ANs account for what % of intracranial tumors?  

13. Apart from NF-2, what are 2 other risk factors that predispose to the development of ANs?  

14. What are the Antoni A and Antoni B areas on histopathology?  

15. For what do ANs stain on immunohistochemistry?  

16. How do bilat ANs fare after Tx when compared to unilat ANs?  

1. What tests are performed on physical exam for pts with CPA lesions?  

2. What CN is being tested when a pt is asked to tighten the ant neck muscles?  

3. Why are pts with CPA lesions often asked to march in place with their eyes closed on physical exam?  

4. What is the best initial screening test for ANs, and what does it usually show?  

5. What is the avg growth rate per yr for ANs?  

6. What % of ANs are stable (shrink/do not grow)?  

7. Is the size of the tumor at presentation predictive of the tumor's growth rate?  

8. Does AN tumor size correlate with hearing loss?  

9. What do brainstem auditory evoked potentials typically show in pts with ANs?  

10. What imaging study is typically performed for ANs?  

11. To what is the “ice cream cone” appearance of ANs on MRI due?  

1. What options are available for AN pts?  

2. When is observation appropriate for ANs?  

3. What f/u is required for AN pts opting for observation?  

4. What are the 4 surgical approaches available for ANs, and what are the prominent disadvantages/advantages of each?  

5. When is Sg the preferred Tx option for ANs?  

6. What are the recurrence rates after GTR for ANs?  

7. What are the overall facial nerve and hearing preservation rates after Sg for ANs?  

8. What are the overall facial nerve and hearing preservation rates after RT for ANs?  

9. What are the long-term LC rates after RT for ANs?  

10. What are some commonly employed doses when SRS/GK SRS is used for ANs?  

11. What has the dose trend been for the Tx of ANs with SRS?  

12. What doses are used with FSR?  

13. What are the hearing preservation rates with FSR?  

14. What recent data suggest better hearing preservation and similar LC rates with lower-dose FSR?  

15. What other RT modalities have been successfully employed in AN?  

16. What important AN studies prospectively compared Sg to SRS? What did they show?  

17. What AN study prospectively evaluated SRS vs. FSR?  

18. What agent has recently been shown to be effective in NF-2 pts with refractory ANs?  

1. The dose falloff to which structures needs to be carefully evaluated with GK SRS for ANs?  

2. What IDL is prescribed in GK? Why? How about for LINAC-based SRS?  

3. What is the difference in the onset of side effects after Sg vs. RT for ANs?  

4. What is the dose threshold above which hearing preservation rates decrease with RT?  

5. What mean cochlea dose is the threshold for hearing preservation with SRS?  

6. What are some toxicities and rates of toxicities after SRS for ANs?  

7. What are the main toxicity differences b/t RT and Sg?