How frequently do you observe transient enlargement of a vestibular schwannoma after SRS?

Transient enlargement of a vestibular schwannoma is not uncommon, and it's appropriate to reassure patients. I image these patients once every 6 months until radiographic stability, and then once yearly.

It is not uncommon to see transient enlargement of VS after SRS particularly for cystic tumors and data from Mayo Clinic showed that only 14% would need intervention due to continued enlargement:

Pollock, PMID 16462477.

If the patient is asymptomatic, I'd repeat an MRI in 6 months and would see the pa...

When post-radiosurgery enlargement occurs, I usually obtain MRI scans at least twice every 6 months to make sure it becomes stable or shrinks. Once stability is confirmed, I do imaging follow-up once a year.