J Neurol Surg B Skull Base 2017; 78(01): 002-010
DOI: 10.1055/s-0036-1584231
Original Article
Georg Thieme Verlag KG Stuttgart · New York

Low-Dose Gamma Knife Radiosurgery for Vestibular Schwannomas: Tumor Control and Cranial Nerve Function Preservation After 11 Gy

Andrew J. Schumacher
1   Department of Radiation Oncology, Kaiser Permanente, Los Angeles, California, United States
,
Rohan R. Lall
2   Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
,
Rishi R. Lall
3   Department of Neurological Surgery, University of Texas Medical Branch, Galveston, Texas, United States
,
Allan Nanney III
2   Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
,
Amit Ayer
2   Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
,
Samir Sejpal
4   Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
,
Benjamin P. Liu
5   Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
,
Maryanne Marymont
4   Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
,
Plato Lee
4   Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
,
Bernard R. Bendok
2   Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
,
John A. Kalapurakal
4   Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
,
James P. Chandler
2   Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
› Institutsangaben
Weitere Informationen

Publikationsverlauf

02. Oktober 2015

19. April 2016

Publikationsdatum:
31. Mai 2016 (online)

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Abstract

Objectives This study aims to report tumor control rates and cranial nerve function after low dose (11.0 Gy) Gamma knife radiosurgery (GKRS) in patients with vestibular schwannomas.

Methods A retrospective chart review was performed on 30 consecutive patients with vestibular schwannomas treated from March 2004 to August 2010 with GKRS at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University. The marginal dose for all patients was 11.0 Gy prescribed to the 50% isodose line. Median follow-up time was 42 months. The median treatment volume was 0.53 cm3. Hearing data were obtained from audiometry reports before and after radiosurgery.

Results The actuarial progression free survival (PFS) based on freedom from surgery was 100% at 5 years. PFS based on freedom from persistent growth was 91% at 5 years. One patient experienced tumor progression requiring resection at 87 months. Serviceable hearing, defined as Gardner–Robertson score of I–II, was preserved in 50% of patients. On univariate and multivariate analyses, only higher mean and maximum dose to the cochlea significantly decreased the proportion of patients with serviceable hearing.

Conclusion Vestibular schwannomas can be treated with low doses (11.0 Gy) of GKRS with good tumor control and cranial nerve preservation.

Note

There was no funding received for this work. There are no financial, institutional, or personal interest disclosures to report.