Repeat stereotactic radiosurgery for acoustic neuromas.
OBJECTIVE
To evaluate the outcome of repeat stereotactic radiosurgery (SRS) for acoustic neuromas, we assessed tumor control, clinical outcomes, and the risk of adverse radiation effects in patients whose tumors progressed after initial management.


METHODS
During a 21-year experience at our center, 1,352 patients underwent SRS as management for their acoustic neuromas. We retrospectively identified 6 patients who underwent SRS twice for the same tumor. The median patient age was 47 years (range, 35-71 years). All patients had imaging evidence of tumor progression despite initial SRS. One patient also had incomplete surgical resection after initial SRS. All patients were deaf at the time of the second SRS. The median radiosurgery target volume at the time of the initial SRS was 0.5 cc and was 2.1 cc at the time of the second SRS. The median margin dose at the time of the initial SRS was 13 Gy and was 11 Gy at the time of the second SRS. The median interval between initial SRS and repeat SRS was 63 months (range, 25-169 months).


RESULTS
At a median follow-up of 29 months after the second SRS (range, 13-71 months), tumor control or regression was achieved in all 6 patients. No patient developed symptomatic adverse radiation effects or new neurological symptoms after the second SRS.


CONCLUSIONS
With this limited experience, we found that repeat SRS for a persistently enlarging acoustic neuroma can be performed safely and effectively.
Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
Hideyuki
H
Kano
Douglas
D
Kondziolka
Ajay
A
Niranjan
Thomas J
TJ
Flannery
John C
JC
Flickinger
L Dade
LD
Lunsford
D000328:Adult; D000368:Aged; D018450:Disease Progression; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000473:pathology / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies