Treatment/Prognosis Flashcards
What options are available for AN pts?
Observation, Sg, or RT
When is observation appropriate for ANs?
Observation is appropriate with small tumors (<2 cm) or no/slow growth without Sx progression. 43% with growth, 51% stable, and 6% regressed without Tx. (Smouha EE et al., Laryngoscope 2005)
What f/u is required for AN pts opting for observation?
Audiometry and MRI scans q6–12 mo
What are the 4 surgical approaches available for ANs, and what are the prominent disadvantages/advantages of each?
Retromastoid: may not be able to achieve GTR/good facial nerve preservation, good hearing preservation, can be used for any size tumor
Middle cranial fossa: GTR, facial nerve preservation moderate-hearing preservation better, good for small <1.5-cm tumors
Translabyrinthine: sacrifices hearing/good facial nerve preservation, recommended if tumor >3 cm
Retrolabyrinthine: sacrifices hearing
When is Sg the preferred Tx option for ANs?
Sg is preferred for large (>4 cm) symptomatic tumors or recurrence/progression after RT.
What are the recurrence rates after GTR for ANs?
<1% (Samii M et al., J Neurosurg 2001; Guerin C et al., Ann Acad Med Singapore 1999; Gormley WB et al., Neurosurgery 1997)
What are the overall facial nerve and hearing preservation rates after Sg for ANs?
After Sg for ANs, there is an 80%–90% facial nerve preservation rate and a 50% hearing preservation rate.
What are the overall facial nerve and hearing preservation rates after RT for ANs?
With SRS: facial nerve preservation rate >95%, hearing preservation 70%–90%
With FSR: ∼95% facial nerve preservation rate and ∼55%–65% hearing preservation rate
What are the long-term LC rates after RT for ANs?
Long-term LC after RT for ANs is 90%–97%. (Lunsford LD et al., J Neurosurg 2005; Combs SE et al., IJROBP 2006; Litre F et al., Radiother Oncol 2013; Hasegawa T et al., J Neurosurg 2013; Maniakas A et al., Otol Neurotol 2012)
What are some commonly employed doses when SRS/GK SRS is used for ANs?
12–13 Gy to 50% IDL is a commonly employed SRS regimen for ANs.
What has the dose trend been for the Tx of ANs with SRS?
The dose was lowered from 16 Gy to 12–13 Gy. Pittsburgh and Japanese data showed similar LC rates but less facial weakness and hearing loss with lower doses.
What doses are used with FSR?
50–55 Gy (in 25–30 fx at 1.8 Gy/fx) if larger (>2–3 cm) lesions. Alternative approach: 25 Gy (5 Gy × 5 fx) with smaller lesions
What are the hearing preservation rates with FSR?
This is controversial, but hearing preservation rates are thought to be slightly better with FSR than with SRS or Sg (94% in Combs SE et al., IJROBP 2005; 81% in Andrews DW et al., IJROBP 2001). Other studies suggest outcomes are equivalent if SRS dose <13 Gy. (Combs SW et al., IJROBP 2011)
What recent data suggest better hearing preservation and similar LC rates with lower-dose FSR?
Thomas Jefferson data: a lower dose of 46.8 Gy (vs. 50.4 Gy) had 100% LC at 5 yrs with a better hearing preservation rate. (Andrews DW et al., IJROBP 2009)
What other RT modalities have been successfully employed in AN?
CyberKnife (Chang SD et al., J Neurosurg 2005) and protons (Weber DC et al., Neurosurg 2003; Vernimmen FJ, Radiother Oncol 2009): worse hearing preservation (not used with tumors >2 cm and if pt can hear well)
