Gamma knife radiosurgery of recurrent atypical neurocytoma. Case report and review of the literature.

Background and Purpose: The goal of this work was to demonstrate the efficacy of stereotactic gamma knife radiosurgery (GKRS) for the treatment of neurocytoma by means of a case report and a comprehensive literature review.
Case Report: A locally recurrent atypical neurocytoma in the area of the left third ventricle thalamic wall occurring 7 years after primary microsurgical resection in a 59-year old woman was treated by GKRS. A marginal dose of 17 Gy was delivered to the surrounding 50% isodose. At the last follow-up, 82 months after radiosurgery, the tumor was locally controlled. For the literature review, computerized bibliographic searches of Pubmed were supplemented with hand searches of reference lists and abstracts of ASCO/ASTRO/ESTRO meetings.
Discussion: The present case confirms the results of the literature analysis. From 1997-2011, a total of 14 series were published providing results of GKRS in 86 patients (89 lesions). The marginal doses, which have been applied, ranged from 9.6-20.0 Gy. With median follow-up intervals between 6 and 185 months, local control was 97.2% and local tumor progression of neurocytoma after GKRS was restricted to only 4 cases. In accordance with our own experience, GKRS was not associated with a relevant early or late toxicity.
Conclusion: GKRS can be assumed to be a safe and effective treatment modality of recurrent or residual neurocytoma.