Gamma Knife Radiosurgery for Central Neurocytoma: Retrospective Analysis of Fourteen Cases with a Median Follow-Up Period of Sixty-Five Months

Abstract

Object: Central neurocytoma (CN) is considered to be a benign neuronal tumor with possible atypical behavior. Microsurgery, radiation therapy (RT) and radiosurgery all have been used in treating this rare disease during the past decade. In this study, the authors present the experience with gamma knife radiosurgery (GKRS) on 14 patients with CN during a median follow-up period of 65 months and document the safety and efficacy of GKRS in the treatment of CN. Methods: Between November 1997 and December 2009, 14 patients pathologically diagnosed with CN were treated with GKRS. Follow-up magnetic resonance imaging (MRI) was performed at 6-month intervals. Tumor volume and adverse radiation effects (ARE) were documented to evaluate tumor response to GKRS. The Karnofsky Performance Scale (KPS) and neurological status were used to assess clinical outcome. The mean radiation dose prescribed to the tumor margin was 12.1 Gy (ranging from 11 to 13 Gy). The mean tumor volume was 19.6 ml (ranging from 3.5 to 48.9 ml). The mean follow-up period was 70 months (ranging from 30 to 140 months), and the median follow-up period was 65 months. Results: Tumor shrinkage was found in all patients at the final MRI follow-up. The mean volume reduction was 69% (ranging from 47 to 87%). No tumor progression, ARE or radiation-related toxicity developed in any of the cases. The KPS scores of all patients were the same or had increased, and the neurological functions were all stable without deterioration at the final follow-up. Conclusion: In our observations, GKRS was found to be an effective and safe alternative as adjuvant therapy for pathology-confirmed CN. The tumor volume and functional outcome can be controlled with a favorable result in long-term observation. Compared with RT and microsurgery, GKRS plays an important role in the treatment of CN as a minimally invasive technique with low morbidity. Regular long-term MRI follow-up should be mandatory to document the tumor response and possible recurrence. Multicenter consortia should be considered for further investigation and evaluation of GKRS for such a rare tumor.

Systematic Analysis of Clinical Outcomes Following Stereotactic Radiosurgery for Central Neurocytoma

“…SRS has been demonstrated to be effective in primary management of CN, particularly in cases less amenable to surgical resection [293150]. In our study, 25 patients (16.7%) were treated with GKRS alone.…”

“…Schild et al [12] first reported the use of SRS for CN in 1997. Since then, multiple case series and systematic reviews have reaffirmed its efficacy [522273134353637383940414243444546474849]. The aforementioned study by Park and Steven [22] represents the first quantitative systematic review of SRS for treatment of CN.…”

“…Thus, subtotal resection (STR) with adjuvant treatment is often necessary [4122628]. Adjuvant therapy for CN traditionally consisted of conventional radiotherapy, but was limited by associated cognitive deficits and other neurotoxicities [22272930313233]. Recently, stereotactic radiosurgery (SRS) is increasingly utilized as an alternative modality because of fewer fractions and associated toxicities [5222731343536373839404142434445464748].…”

Clinical characteristics and prognostic factors of brain central neurocytoma

“…Surgery was the primary initial treatment for CN [23–25], but whether complete resection surgery correlates significantly with overall survival was still disputed [8, 24, 26, 27]. Meanwhile, radiosurgery was also reported by some small sample studies to perform nice effect and little complications to CNs in the past several years [28–31]. Conventional radiotherapy was mainly applied for the management of residual or recurrent CNs [32, 33], but its effect to overall survival was still full of controversial [8, 24, 34–36], and the radiation-induced toxicity was also hard to be ignored for the long-time clinical course [37, 38].…”

Treatment strategies for huge central neurocytomas

“…GKRS as a primary or secondary treatment option for CNs was also demonstrated in several researches [6,9,24,25] . In our series, CNs in two patients with STR(+GKRS) recurred or progressed postoperatively and were treated with (repeated) GKRS, and no recurrence was found during the follow-up period.…”