Abstract
Objective: To evaluate the results of stereotactic radiosurgery treating vestibular schwannomas secondary to type 2 neurofibromatosis.
Methods: A retrospective review of 122 type 2 neurofibromatosis vestibular schwannomas consecutively treated in 96 patients. Tumour control was assessed by recourse to surgical intervention, by serial radiological imaging, and by the calculation of relative growth ratios in patients (n=29) habouring untreated contralateral tumours to act as internal controls. Hearing function was assessed with Gardner-Robertson grades and with averaged pure tone audiogram thresholds. Other complications are detailed.
Results: Applying current techniques, eight years after radiosurgery it was estimated that 20% of patients will have undergone surgery for their tumour, 50% will have radiologically controlled tumours, and in 30% there will be some variable concern about tumour control, but up to that time they will have been managed conservatively. Relative growth ratios one and two years after treatment indicate that radiosurgery confers a significant (p=0.01) advantage over the natural history of the disease. Analysis of these ratios beyond two years was precluded by the need to intervene and radiosurgically treat the contralateral control tumours in more than 50% of the cases. This growth control was achieved with 40% of patients retaining their Gardner-Robertson hearing grades three years after treatment, (40% having some deterioration in grade, 20% becoming deaf). Pure tone audiogram results suggest some progressive long term hearing loss, although interpretation of this is difficult. Facial and trigeminal neuropathy occurred in 5% and 2%.
Conclusions: Radiosurgery is a valuable minimally invasive alternative treatment for these tumours. For most patients, it controls growth or defers the need for surgery, or both. There is a price in terms of hearing function, although this may compare favourably with the deafness associated with the natural history of the disease, and with surgery. In deciding on therapy, patients should be aware of this treatment option.
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Selected References
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- Baldwin D., King T. T., Chevretton E., Morrison A. W. Bilateral cerebellopontine angle tumors in neurofibromatosis type 2. J Neurosurg. 1991 Jun;74(6):910–915. doi: 10.3171/jns.1991.74.6.0910. [DOI] [PubMed] [Google Scholar]
- Bari M. E., Forster D. M. C., Kemeny A. A., Walton L., Hardy D., Anderson J. R. Malignancy in a vestibular schwannoma. Report of a case with central neurofibromatosis, treated by both stereotactic radiosurgery and surgical excision, with a review of the literature. Br J Neurosurg. 2002 Jun;16(3):284–289. doi: 10.1080/02688690220148888. [DOI] [PubMed] [Google Scholar]
- Evans D. G., Huson S. M., Donnai D., Neary W., Blair V., Newton V., Harris R. A clinical study of type 2 neurofibromatosis. Q J Med. 1992 Aug;84(304):603–618. [PubMed] [Google Scholar]
- Gardner G., Robertson J. H. Hearing preservation in unilateral acoustic neuroma surgery. Ann Otol Rhinol Laryngol. 1988 Jan-Feb;97(1):55–66. doi: 10.1177/000348948809700110. [DOI] [PubMed] [Google Scholar]
- Jäskeläinen J., Paetau A., Pyykkö I., Blomstedt G., Palva T., Troupp H. Interface between the facial nerve and large acoustic neurinomas. Immunohistochemical study of the cleavage plane in NF2 and non-NF2 cases. J Neurosurg. 1994 Mar;80(3):541–547. doi: 10.3171/jns.1994.80.3.0541. [DOI] [PubMed] [Google Scholar]
- Kalamarides M., Grayeli A. B., Bouccara D., Dahan E. A., Sollmann W. P., Sterkers O., Rey A. Hearing restoration with auditory brainstem implants after radiosurgery for neurofibromatosis type 2. J Neurosurg. 2001 Dec;95(6):1028–1033. doi: 10.3171/jns.2001.95.6.1028. [DOI] [PubMed] [Google Scholar]
- Kida Y., Kobayashi T., Tanaka T., Mori Y. Radiosurgery for bilateral neurinomas associated with neurofibromatosis type 2. Surg Neurol. 2000 Apr;53(4):383–390. doi: 10.1016/s0090-3019(00)00174-9. [DOI] [PubMed] [Google Scholar]
- Kishore A., O'Reilly B. F. A clinical study of vestibular schwannomas in type 2 neurofibromatosis. Clin Otolaryngol Allied Sci. 2000 Dec;25(6):561–565. doi: 10.1046/j.1365-2273.2000.00421.x. [DOI] [PubMed] [Google Scholar]
- Kondziolka D., Lunsford L. D., McLaughlin M. R., Flickinger J. C. Long-term outcomes after radiosurgery for acoustic neuromas. N Engl J Med. 1998 Nov 12;339(20):1426–1433. doi: 10.1056/NEJM199811123392003. [DOI] [PubMed] [Google Scholar]
- Linskey M. E., Lunsford L. D., Flickinger J. C. Tumor control after stereotactic radiosurgery in neurofibromatosis patients with bilateral acoustic tumors. Neurosurgery. 1992 Nov;31(5):829–839. doi: 10.1227/00006123-199211000-00002. [DOI] [PubMed] [Google Scholar]
- Matthies C., Thomas S., Moshrefi M., Lesinski-Schiedat A., Frohne C., Battmer R. D., Lenarz T., Samii M. Auditory brainstem implants: current neurosurgical experiences and perspective. J Laryngol Otol Suppl. 2000;(27):32–36. doi: 10.1258/0022215001904699. [DOI] [PubMed] [Google Scholar]
- Rowe Jeremy G., Radatz Matthias, Walton Lee, Kemeny Andras A. Stereotactic radiosurgery for type 2 neurofibromatosis acoustic neuromas: patient selection and tumour size. Stereotact Funct Neurosurg. 2002;79(2):107–116. doi: 10.1159/000070106. [DOI] [PubMed] [Google Scholar]
- Samii M., Matthies C. Management of 1000 vestibular schwannomas (acoustic neuromas): surgical management and results with an emphasis on complications and how to avoid them. Neurosurgery. 1997 Jan;40(1):11–23. doi: 10.1097/00006123-199701000-00002. [DOI] [PubMed] [Google Scholar]
- Samii M., Matthies C., Tatagiba M. Management of vestibular schwannomas (acoustic neuromas): auditory and facial nerve function after resection of 120 vestibular schwannomas in patients with neurofibromatosis 2. Neurosurgery. 1997 Apr;40(4):696–706. doi: 10.1097/00006123-199704000-00007. [DOI] [PubMed] [Google Scholar]
- Subach B. R., Kondziolka D., Lunsford L. D., Bissonette D. J., Flickinger J. C., Maitz A. H. Stereotactic radiosurgery in the management of acoustic neuromas associated with neurofibromatosis Type 2. J Neurosurg. 1999 May;90(5):815–822. doi: 10.3171/jns.1999.90.5.0815. [DOI] [PubMed] [Google Scholar]