Acoustic neuroma

Epidemiology
2500 - 3000 cases/year in US
NF2: bilateral acoustic neuroma is essentially diagnostic of NF2

Pathology
Schwann cell/nerve sheath tumor

Clinical
Often incidentally discovered on brain MRI
Unilateral hearing loss
Large tumors cause CN VII, V palsies, brainstem compression

Surgery
Complete resection is curative
Complications: facial nerve palsy (40%), worsened hearing loss (60%)
Recurrence rate 30 -50% after subtotal resection

Radiosurgery
12 - 14Gy to margin
Pitt reports 5-year control > 95%
Facial N. palsy 0% for doses < 13Gy, 2% for doses > 13Gy
Hearing preservation in 70%
(PMID 11147876)

Fractionated RT
Consider if large tumor with brainstem compression, intact hearing
54Gy in 1.8Gy fractions also associated with > 95% tumor control (PMID 15987541)

Observation
Option in elderly/asymptomatic patients