What planning and dose constraints are you using for 5-fraction hypofractionated FRST for vestibular schwannoma?

When using fractionated SRS (fSRT) of 25 Gy in 5 fractions for vestibular schwannomas, I use only 2 constraints: the brain stem and the cochlea, if the patient has serviceable hearing. In this case, the only OAR needed is the brain stem, 23 Gy <0.5 cc. I don't worry about the trigeminal nerve as it ...

Great question. An important consideration is also the amount of time they have had no serviceable hearing, and what that actually means. If they still have sensorineural hearing of any frequency (even very low), they can sometimes regain some hearing function following treatment.

I always default t...

For a 5-fraction FSRS regimen, a more conservative cochlear Dmax of ≤8 Gy (based on radiobiologic modeling with an α/β of 2.0) would be considered reasonable. This corresponds to a biologically effective dose (BED) and EQD2 comparable to a single-fraction cochlear Dmax of 4 Gy levels associated with...