Tumors are typically described as small (less than 1.5 cm)

Small

Management of small consists of 3 options:

Observation with imaging follow-up

Radiosurgery.

And/or tumor removal.

Koos Grade 1

Data suggest that Koos I patients should be treated early with Gamma Knife radiosurgery (GKS), before tumor growth and/or hearing deterioration, as they have the highest probability of hearing preservation 1).

1)
Levivier M, Tuleasca C, Mercy G, Schiappacasse L, Zeverino M, Maire R. Should Koos grade I vestibular schwannomas be treated early with gamma knife surgery? A subgroup analysis in a series of 190 consecutive patients. Neurochirurgie. 2014 Dec;60(6):331. doi: 10.1016/j.neuchi.2014.10.028. Epub 2014 Nov 21. PubMed PMID: 25480195.