Gamma Knife surgery for neurocytoma

Gamma Knife radiosurgery for central neurocytoma: a quantitative systematic review and metanalysis

Central neurocytomas (CN) are rare tumors within the central nervous system. Originating from the septum pellucidum and subependymal cells, they are typically found in the third and lateral ventricles. For this reason, they may lead to hydrocephalus and increased intracranial pressure. CNs are generally benign lesions that exhibit locally aggressive behavior and a high recurrence rate. Complete surgical resection is the preferred treatment; however, due to their anatomical location, this is often not feasible. Based on these findings, Gamma Knife radiosurgery (GKRS) has been introduced for managing both residual and recurrent tumors and as an initial therapy in selected cases. This study aimed to systematically review the available knowledge regarding GKRS for CN. A systematic investigation of the scientific literature was undertaken through an exhaustive search across prominent databases, including PubMed, Web of Science, and Google Scholar, by employing precise MeSH terms such as "Central neurocytoma," "Radiosurgery," "Gamma Knife," and "Stereotactic Radiosurgery." A comprehensive quantitative systematic review and meta-analysis were meticulously conducted, focusing on cases of CN treated with GKRS for a thorough evaluation of outcomes and efficacy. Seventeen articles, including 289 patients, met the inclusion criteria. Random effects meta-analysis estimates for disease control and local tumor control were 90% (95% CI 87-93%; I2 = 0%, p < 0.74) and 94% (95% CI 92-97%; I2 = 0%, p < 0.98), respectively. When considering only studies with at least 5 years of follow-up, progression-free survival was 89% (95% CI 85-94%; I2 = 0.03%, p < 0.74). The mean clinical control rate was 96%. This systematic review and meta-analysis confirmed the safety and efficacy of GKRS in managing CN.

Less common intraparenchymal tumors

The chapter outlines the management of a great variety of rare intraparenchymal tumors. For some like medulloblastomas or ependymomas, GKNS has little to offer. For others like neurocytomas, primary central nervous system lymphomas, and papillary pineal tumors the current findings look most hopeful. For choroid plexus papillomas there is currently not enough information to define the role of GKNS in their treatment. Pineal region tumors are a complex and varied group of neoplasms. Their complexity, variety and ethnic variability means that defining the role of GKNS will require continuing research before a consensus about management can be reached.

Impact of Adjuvant Radiotherapy in Patients with Central Neurocytoma: A Multicentric International Analysis

Simple Summary

Central neurocytoma is a rare tumor accounting for <0.5% of all intracranial tumors. We analyzed 33 patients treated with surgical resection with or without radiotherapy from ten closely cooperating institutions in Germany, Egypt, and Jordan. Patients who received radiotherapy had longer progression-free survival with an acceptable toxicity profile.

Abstract

Background: Central neurocytoma (CN) is a rare tumor accounting for <0.5% of all intracranial tumors. Surgery ± radiotherapy is the mainstay treatment. This international multicentric study aims to evaluate the outcomes of CNs patients after multimodal therapies and identify predictive factors. Patients and methods: We retrospectively identified 33 patients with CN treated between 2005 and 2019. Treatment characteristics and outcomes were assessed. Results: All patients with CN underwent surgical resection. Radiotherapy was delivered in 19 patients. The median radiation dose was 54 Gy (range, 50–60 Gy). The median follow-up time was 56 months. The 5-year OS and 5-year PFS were 90% and 76%, respectively. Patients who received radiotherapy had a significantly longer PFS than patients without RT (p = 0.004) and a trend towards longer OS. In addition, complete response after treatments was associated with longer PFS (p = 0.07). Conclusions: Using RT seems to be associated with longer survival rates with an acceptable toxicity profile.

The last decade's experience of management of central neurocytomas: Treatment strategies and new options

Background:

The purpose of the presented work is to evaluate the last decade’s experience in surgical management of central neurocytoma (CN) and elucidate on the treatment strategies and new options.

Methods:

The current series consists of the remaining 125 patients (70 females and 55 males) operated on during the past decade from 2008 to 2018. Most tumors were resected through transcortical (n = 76, 61%), or transcallosal (n = 40, 32%) approaches. In 5 (4%) patients with predominantly posterior location of the tumor, non-dominant superior parietal lobule approach was utilized. Both approaches (transcortical + transcallosal) were used in 4 (3%) of cases. Seven consecutive patients with large CN underwent prophylactic intraventricular stenting to prevent hydrocephalus.

Results:

Gross total resection was achieved in 45 patients (36%), subtotal resection (STR) in 40 (32%) cases. After surgery, 63 (50%) patients had neurocognitive problems, including disorientation, attention deficit, global amnesia, short-term memory deficits, and perceptual motor and social cognition problems. A total of 26 patients (21%) had postoperative hemorrhage in the resection bed. Obstructive hydrocephalus was noted in 25 (20%) patients. The entrapment of the occipital and/or temporal horns was observed in seven cases. None of the seven patients with prophylactic intraventricular stents required shunting.

Conclusion:

Although high rates of gross total or STR can be expected, the mortality and morbidity remain significant even in the modern neurosurgical era. Prophylactic intraventricular stenting in patients with large posteriorly located tumors with hydrocephalus may prevent ventricular entrapment and shunting. The main risk factors for recurrence are presence of residual disease and Ki-67 index over 5%. Recurrent symptomatic tumors should be treated surgically, whereas asymptomatic progression can be managed with stereotactic radiosurgery. Both treatment modalities are associated with low risk of complications and high tumor control rates.

Gamma Knife radiosurgery as a primary treatment for central neurocytoma

OBJECTIVE

This study was performed to evaluate the role of Gamma Knife radiosurgery (GKRS) as a primary treatment for central neurocytomas (CNs).

METHODS

The authors retrospectively assessed the treatment outcomes of patients who had undergone primary treatment with GKRS for CNs in the period between December 2001 and December 2018. The diagnosis of CN was based on findings on neuroimaging studies. The electronic medical records were retrospectively reviewed for additional relevant preoperative data, and clinical follow-up data had been obtained during office evaluations of the treated patients. All radiographic data were reviewed by a dedicated neuroradiologist.

RESULTS

Fourteen patients were treated with GKRS as a primary treatment for CNs in the study period. Seven patients (50.0%) were asymptomatic at initial presentation, and 7 (50.0%) presented with headache. Ten patients (71.4%) were treated with GKRS after the diagnosis of CN based on characteristic MRI findings. Four patients (28.6%) initially underwent either stereotactic or endoscopic biopsy before GKRS. The median tumor volume was 3.9 cm3 (range 0.46–18.1 cm3). The median prescription dose delivered to the tumor margin was 15 Gy (range 5.5–18 Gy). The median maximum dose was 30 Gy (range 11–36 Gy). Two patients were treated with fractionated GKRS, one with a prescription dose of 21 Gy in 3 fractions and another with a dose of 22 Gy in 4 fractions. Control of tumor growth was achieved in all 14 patients. The median volume reduction was 26.4% (range 0%–78.3%). Transient adverse radiation effects were observed in 2 patients but resolved with improvement in symptoms. No recurrences were revealed during the follow-up period, which was a median of 25 months (range 12–89 months).

CONCLUSIONS

Primary GKRS for CNs resulted in excellent tumor control rates without recurrences. These results suggest that GKRS may be a viable treatment option for patients with small- to medium-sized or incidental CNs.

[Central neurocytomas: long-term treatment outcomes]

Central neurocytoma is a rare benign brain tumor. These tumors may be giant and accompanied by compression of ventricular system and surrounding structures. Modern treatment of brain neurocytoma includes extended resection and restoration of normal CSF circulation. Surgical treatment does not often lead to total resection of these tumors. Redo resection was preferred in patients with tumor progression for a long time. In the last decade, various authors report stereotactic irradiation for continued tumor growth to ensure local growth control. This study was aimed at evaluation of postoperative outcomes in patients with brain neurocytomas, as well as treatment of tumor progression in long-term period.

OBJECTIVE

To analyze recurrence-free survival in patients with brain neurocytomas, risk factors of recurrence-free survival, effectiveness of various treatments for tumor progression and delayed complications.

MATERIAL AND METHODS

Long-term postoperative follow-up data of patients with brain neurocytomas are reported in the manuscript. We analyzed recurrence-free survival and risk factors of recurrence-free survival, treatment outcomes in patients with progression of brain neurocytomas, long-term complications and their prevention.

RESULTS

Follow-up included 84 out of 115 patients with brain neurocytoma after surgical treatment in 2008-2017. Follow-up period ranged from 2 to 10 years (mean 6 years) after resection. Most patients had regression of neurological symptoms after surgery. Continued tumor growth within 12-96 months after surgery occurred in 26 (30.19%) out of 84 patients (19 cases after partial resection and 7 cases after total resection according to MRI data). Two-year recurrence-free survival was 94%, 5-year survival - 83%. Risk factors of continued tumor growth were resection quality and Ki-67 index. Redo resection was performed in 7 cases. Eleven patients underwent stereotactic irradiation for tumor progression. Indications for stereotactic irradiation of central neurocytoma are MR data on continued growth of lateral ventricle tumor without signs of ICH and CSF flow impairment. There were no cases of hemorrhage inside the residual tumor and CSF flow impairment in early postoperative period after redo resection. In all cases (n=11), stereotactic irradiation (mean follow-up 2.5 years) ensured satisfactory control of tumor growth with reduction of the neoplasm in 4 cases and no tumor growth in 7 cases.

CONCLUSION

Resection of central neurocytoma ensures long-term recurrence-free period. The main causes of tumor recurrence are partial resection and high proliferative activity (Ki-67 index over 5%). Redo resection is advisable for tumor progression followed by CSF flow impairment. In case of continued growth of neurocytoma without signs of intracranial hypertension, stereotactic irradiation with various fractionation modes ensures effective and safe control of tumor growth.

Gamma Knife radiosurgery for the treatment of central neurocytoma: a single-institution experience of 25 patients

Central neurocytomas (CNs) are extremely rare tumors that account for 0.1-0.5% of all intracranial neoplasms. Recently, Gamma Knife radiosurgery (GKRS) has become a treatment option in patients with CN. We aimed to evaluate the efficacy and safety of GKRS in 25 CN patients and review the results along with relevant literature. GKRS patient database was searched, and 25 patients who underwent GKRS for CN between 2009 and 2018, were evaluated retrospectively. The study cohort included 15 female and ten male patients with a median age of 32 years (range, 5-60). The most common presenting symptom was headache (88%). The neurological examination was unremarkable in all patients, except for one patient with decreased vision. Twenty patients (80%) had a history of surgical resection. Most of the tumors (92%) were located in the ventricles, and the median tumor volume was 4.8 cm³ (range, 0.8-28.1). The median marginal dose was 14 Gy (range, 12-15) to a median isodose of 50% (range, 40-50). Following a median follow-up of 80 months (range, 36-138), local tumor control was achieved in 100% of patients. Distant recurrence was observed in one patient (4%). No adverse radiation effect was observed. Regarding non-specific post-GKRS symptoms, one patient experienced a prolonged headache, and one epileptic patient experienced a brief partial seizure. In our patient cohort, GKRS yielded favorable local tumor control (100%) during a median follow-up of 6.6 years. Our series demonstrates that GKRS is an effective and safe treatment option for patients with primary or residual CNs.

[Choice optimisation of radiation therapy technique for central neurocytomas from literature data]

Neurocytomas represent 0,25 to 0,5 of brain tumours. These tumours have neuronal differentiation. It's a young adult disease. The main treatment is neurosurgery. The place of other therapies is still unclear, noticeably with regards to radiotherapy. This review aim is to determine the place and the modalities of radiotherapy in the management of neurocytomas. A literature search using PubMed allowed to select the most relevant studies. Finally, 22 studies were selected according to pre-established criteria to answer the problem. All studies were retrospective studies except one. The analysis conclusion defined radiotherapy as a treatment of choice in selected patients, when surgical resection was incomplete or when tumour was atypical.

Stereotactic radiosurgery for central neurocytomas: an international multicenter retrospective cohort study

OBJECTIVE

Central neurocytomas (CNs) are uncommon intraventricular tumors, and their rarity renders the risk-to-benefit profile of stereotactic radiosurgery (SRS) unknown. The aim of this multicenter, retrospective cohort study was to evaluate the outcomes of SRS for CNs and identify predictive factors.

METHODS

The authors retrospectively analyzed a cohort of patients with CNs treated with SRS at 10 centers between 1994 and 2018. Tumor recurrences were classified as local or distant. Adverse radiation effects (AREs) and the need for a CSF shunt were also evaluated.

RESULTS

The study cohort comprised 60 patients (median age 30 years), 92% of whom had undergone prior resection or biopsy and 8% received their diagnosis based on imaging alone. The median tumor volume and margin dose were 5.9 cm3 and 13 Gy, respectively. After a median clinical follow-up of 61 months, post-SRS tumor recurrence occurred in 8 patients (13%). The 5- and 10-year local tumor control rates were 93% and 87%, respectively. The 5- and 10-year progression-free survival rates were 89% and 80%, respectively. AREs were observed in 4 patients (7%), but only 1 was symptomatic (2%). Two patients underwent post-SRS tumor resection (3%). Prior radiotherapy was a predictor of distant tumor recurrence (p = 0.044). Larger tumor volume was associated with pre-SRS shunt surgery (p = 0.022).

CONCLUSIONS

Treatment of appropriately selected CNs with SRS achieves good tumor control rates with a reasonable complication profile. Distant tumor recurrence and dissemination were observed in a small proportion of patients, which underscores the importance of close post-SRS surveillance of CN patients. Patients with larger CNs are more likely to require shunt surgery before SRS.

Systematic Analysis of Clinical Outcomes Following Stereotactic Radiosurgery for Central Neurocytoma

Central neurocytoma (CN) typically presents as an intraventricular mass causing obstructive hydrocephalus. The first line of treatment is surgical resection with adjuvant conventional radiotherapy. Stereotactic radiosurgery (SRS) was proposed as an alternative therapy for CN because of its lower risk profile. The objective of this systematic analysis is to assess the efficacy of SRS for CN. A systematic analysis for CN treated with SRS was conducted in PubMed. Baseline patient characteristics and outcomes data were extracted. Heterogeneity and publication bias were also assessed. Univariate and multivariate linear regressions were used to test for correlations to the primary outcome: local control (LC). The estimated cumulative rate of LC was 92.2% (95% confidence interval: 86.5-95.7%, p<0.001). Mean follow-up time was 62.4 months (range 3-149 months). Heterogeneity and publication bias were insignificant. The univariate linear regression models for both mean tumor volume and mean dose were significantly correlated with improved LC (p<0.001). Our data suggests that SRS may be an effective and safe therapy for CN. However, the rarity of CN still limits the efficacy of a quantitative analysis. Future multi-institutional, randomized trials of CN patients should be considered to further elucidate this therapy.

Central Versus Extraventricular Neurocytoma in Children: A Clinicopathologic Comparison and Review of the Literature

BACKGROUND

Central neurocytomas (CN) are rare pediatric CNS tumors most often with a benign clinical course. Occasionally, these tumors occur outside the ventricles and are called extraventricular neurocytomas (EVN). We present a retrospective institutional analysis of children with neurocytoma with prolonged follow-up.

PROCEDURE

Twelve patients were diagnosed with neurocytoma at our institution between 1993 and 2004.

RESULTS

Six patients were male and the median age at diagnosis was 12 years (1.5 to 16 y). Seven patients had CN and 5 had EVN. Presenting symptoms included headaches (67%), vomiting (50%), nausea (33%), seizures (33%), and mental status changes (25%). Obstructive hydrocephalus was present at diagnosis in 42% of the cases. Younger age and seizures were more common in patients with EVN. Gross total resection (GTR) was achieved in 42% (5/12) of the patients. Patients with GTR received no adjuvant therapy upfront; 1 patient subsequently had recurrence with leptomeningeal disease. Patients with subtotal resection received additional treatment: 1 underwent reoperation (GTR), 2 patients received focal radiation, 2 patients received adjuvant chemotherapy, and 2 patients received craniospinal irradiation followed by chemotherapy. The 20-year overall survival for this cohort was 83% with event free survival of 56%. Overall survival for CNs was 100%, versus 40% for EVN. Event free survival for CNs was 57% and 53% for the EVNs. An MIB-1 fraction >2% was associated with worse prognosis.

CONCLUSIONS

Neurocytomas are rare brain tumors in children usually cured with GTR. Adjuvant focal radiation therapy and/or chemotherapy may improve disease control in cases with subtotal resection, but case-by-case analysis should be done. EVNs might be associated with worse outcome due to a higher proliferative index.

Rapid tumor growth with glial differentiation of central neurocytoma after stereotactic radiosurgery

Although stereotactic radiosurgery (SRS) is effective for central neurocytoma (CN), the long-term outcome of SRS remains unclear. We present a case of recurrent CN that was diagnosed 10years after surgical resection and consecutive stereotactic radiotherapy. The patient was treated with SRS for the recurrent tumor, but underwent two-staged surgery once again due to rapid tumor growth. Histological features of the recurrent tumor were consistent with the diagnosis of CN. However, an increased Ki-67 proliferation index (3.4%), aberrant angiogenesis and glial differentiation of the tumor cells were observed, which were not identified in the initial CN. In addition, vascular endothelial growth factor (VEGF) and VEGF receptor were highly expressed in the recurrent tumor cells, as well as in the vascular endothelial cells. Our case suggests that malignant transition with aberrant angiogenesis and glial differentiation may be attributable to SRS.

Treatment Results of Gamma Knife Radiosurgery for Central Neurocytoma: Report of a Japanese Multi-Institutional Cooperative Study

OBJECTIVE

Central neurocytoma (CN) is a rare benign neuronal tumor, and a limited number of reports have described the usefulness of radiosurgery for a relatively large group of patients. We evaluated the effectiveness and outcomes of Gamma Knife radiosurgery (GKS) for CN in a Japanese multi-institutional study.

METHODS

We performed retrospective analysis of 36 patients with CN who were treated with GKS in 12 institutes in Japan. All patients underwent surgery before GKS. The median tumor volume at GKS was 4.9 mL (range, 0.07-23.4 mL), and the median radiation dose prescribed to the tumor margin was 15 Gy (range, 10-20 Gy). The median follow-up period was 54.5 months (range, 3-180 months).

RESULTS

The local tumor progression-free survival rates at 5 and 10 years were 94% and 86%, respectively. Three patients developed distant dissemination 16-90 months later. Overall progression-free survival was unrelated to the prescribed dose (<15 Gy vs. ≥15 Gy, P = 0.62), tumor size (<6 mL vs. ≥6 mL, P = 0.46), gender (P = 0.36), age (<30 vs. ≥30 years, P = 0.37), target of GKS (residual vs. recurrence, P = 0.90), and type of enhancement (homogeneous vs. inhomogeneous, P = 0.19). Two permanent complications occurred with 1 intratumoral hemorrhage and 1 radiation injury.

CONCLUSIONS

GKS is effective for CN because of its high rate of long-term local tumor control. GKS may have a potential role as a primary treatment for asymptomatic, relatively small tumors in the absence of hydrocephalus without surgical resection.

The management of incidental central neurocytoma

This article elucidates the role of stereotactic radiosurgery for the management of central neurocytoma. This rare intraventricular tumor is usually benign and is best treated with surgical excision if the tumor is large and symptomatic. However, some distinctive neuroimaging features are found in this tumor that help to identify the tumor based on detailed MRI and computed tomography examinations. The cumulative experience shows that single-session radiosurgery using Gamma Knife radiosurgery is an effective and safe alternative treatment of incidental central neurocytoma. After radiosurgery, a serial MRI examination performed every 6 months for long-term follow-up is necessary to monitor radiosurgical response of the tumor.

The management of central neurocytoma: radiosurgery

Stereotactic radiosurgery (SRS) has evolved into a mainstay in the primary and adjuvant management of most intracranial tumors. Central neurocytomas are rare, usually benign, intraventricular tumors that can be challenging to completely resect and often recur. Adjuvant therapy has been suggested for residual or recurrent tumors, especially in the setting of atypical neurocytomas. The limited data available suggest that SRS is a highly effective treatment approach for primary and adjuvant therapy, with tumor control rates of 80% to 90%. Due to its highly conformal and selective nature, SRS avoids the inconvenience and delayed toxicity of conventional radiation therapy.

Radiosurgery for central neurocytoma: long-term outcome and failure pattern

Despite the favorable outcomes of radiosurgery for central neurocytoma (CN), these results are based on case series that included a limited number of patients and short follow-up periods because of the scarcity of CN. Because CN is a benign tumor with an indolent clinical course, long-term follow-up and analysis of failure pattern are required for the establishment of the role of radiosurgery in the management of CN. Twenty consecutive patients (10 patients who received Gamma Knife radiosurgery (GKRS) as a primary treatment and 10 patients who received GKRS as a secondary treatment) with a radiological follow-up period ≥36 months were included in this study. The mean radiological follow-up duration was 100 months (range 43-149 months). The mean tumor volume was 10.4 cm(3) (range 0.4-36.4 cm(3)) and the mean marginal dose was 15.4 Gy (range 9-20 Gy). Local control failure was found in six patients at the last radiological follow-up. Overall actuarial local control rates were 89.5 % at 5 years and 83.1 % at 10 years. The primary GKRS group included two cases with local failure, with cyst formation or local recurrence. In contrast, in the secondary GKRS group, local control failure was found in four cases (including three cases with an "out-of-field recurrence" pattern) and occurred earlier compared with the primary GKRS group. Our study suggests that GKRS could be a primary or secondary treatment option for CN. However, long-term radiological follow-up is mandatory. In particular, more careful consideration during margin delineation and planning procedure is required in the secondary GKRS group.

Frontal transcortical approach in 12 central neurocytomas

BACKGROUND

Central neurocytomas (CN) are rare intraventricular tumors with benign clinical behavior that typically affect young adults. Although a favorable prognosis is generally expected after adequate management, there is no general consensus on the standard of therapy. We evaluated the efficacy and safety of radical surgery for the management of CN.

METHODS

Between 1996 and 2010, 12 patients with CN (eight males and four females; range, 18 to 62 years; mean age, 28.5 years) were surgically treated in our institution. The initial goal of therapy was complete resection through a frontal transcortical approach, and repeat surgery was done in cases of residual or recurrent disease. The mean follow-up period was 51.2 months (range, 14-149 months).

RESULTS

Complete resection was achieved in all patients either with primary (nine patients, 75 %) or second-look surgery (three patients, 25 %). No mortalities occurred and there were four surgery-related complications (two events of transient hemiparesis, one transient aphasia, and onepostoperative subdural hygroma). All patients were alive with normal activities of daily living at the last follow-up. Two patients (16.6 %) experienced a single recurrence at 26 and 66 months, one of whom underwent redo-surgery.

CONCLUSION

For the management of CN, complete resection is feasible, effective, and safe. Repeat surgery may be a viable option in cases of residual or recurrent disease and the use of radiotherapy can be avoided in this young population.

Stereotactic radiosurgery for central neurocytoma: a quantitative systematic review

Central neurocytoma was originally described as a rare benign neuronal tumor. However, progression and local recurrences after surgery are well recognized. Stereotactic radiosurgery is another option for treatment of CN. In order to evaluate the efficacy of SRS, we performed a quantitative systematic review of the available data on SRS for CN. To identify eligible studies, systematic searches for all CNs treated with SRS were conducted in major scientific publication databases. English studies published prior to May 2011 were reviewed and summarized with reference to the inclusion and exclusion criteria. Tumor local control was analyzed. Heterogeneity and publication bias were assessed, and the summary control rate and 95%confidence interval (CI) were calculated from the raw data.Of 35 eligible studies, five with a total of 64 CNs were included in this quantitative analysis. Four studies reported a mean or median follow-up time of[60 months. The test of heterogeneity was non-significant among the included studies. Publication bias was observed as indicated by an asymmetric funnel plot. There was non-significance in Begg’s test and Egger’s test. The estimated cumulative rate of neuro-imaging tumor control was 91.1% (95%CI = 80.2–96.3%) at a mean follow-up of 59.3 months(range 6–140 months). The P-value was\0.0001 under a random-effect model. Sensitivity analysis showed a similar summary control rates (89.5–93.7%). Based on the summary local control rate of SRS for CN found in this quantitative analysis, we suggest that single session SRS is an effective and safe alternative therapy for recurrent or residual CN. However, the results of our analysis are limited by the predominance of case series studies due to scarcity of published research. Further randomized trials of CN patients via multicenter consortia should be considered for supplementing the weak points in our quantitative analysis.

Gamma knife radiosurgery for cranial neurocytomas

Gamma-knife surgery may be an effective alternative for treatment of central neurocytomas owing to its relative safety compared with conventional radiotherapy. In this paper we present results of gamma-knife treatment (GKS) of residual or recurrent neurocytomas. Twenty-two patients (14 female, 8 male) with recurrent or residual neurocytomas who underwent GKS were included. Diagnosis was based on histological findings. The proliferative potential of the tumors was examined by immunostaining with MIB-1 antibody, which is specific for detection of Ki-67 antigen. Tumor volume was determined by using post-gadolinium magnetic resonance images. After GKS treatment, MR imaging was scheduled at three-month intervals in the first year, at six months intervals in the second year, and yearly thereafter. Histopathological diagnoses were: 18 cases of central neurocytomas, two liponeurocytomas, one cerebral neurocytoma and one cerebellar neurocytoma. The MIB1 labeling index (LI) varied from 0 to 5.7%. Marked reduction in tumor volume was seen in 15 patients. In six patients, the tumor volume remained unchanged, and progression was observed for one patient. No complications because of GKS were noted. Shrinking effect on tumor volume increased with increasing duration of follow-up. On the other hand, high MIB labeling index did not seem to have an effect on tumor response to GKS treatment. Findings of this study suggest that GKS is an effective and safe treatment alternative for residual or recurrent neurocytomas. However, its effectiveness should be confirmed with larger studies.

Gamma knife radiosurgery for central neurocytoma: retrospective analysis of fourteen cases with a median follow-up period of sixty-five months

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.

Recidivant central neurocytoma treated with radiosurgery: a case report

Central neurocytoma is a rare intraventricular brain tumour that affects young people and presents with increased intracranial pressure secondary to obstructive hydrocephalus. Typically, it has a favourable prognosis after complete resection. In some cases the clinical course could be more aggressive. In this report, we describe a case of recurrent central neurocytoma treated with radiosurgery after two consecutive relapses. An asymptomatic radionecrosis developed after that. At the moment the patient is in complete recovery. Finally, we discuss the role of postoperative irradiation in the treatment of this rare tumour.

[Central neurocytoma: case report]

In this study, we report one case of central neurocytoma treated in our department. It is a benign tumor of the lateral ventricles of the brain with neuronal differentiation. The clinical symptoms mainly consisted in intracranial hypertension syndrome. Immunohistochemical studies are necessary for the histopathological diagnosis. The treatment of choice is surgical. To guarantee good progression, complete ablation is necessary. The clinical progression, radiological aspects, treatment, histopathology, and postoperative progression will be discussed.

THE APPLICATION OF STEREOTACTIC RADIOSURGERY TO DISORDERS OF THE BRAIN

STEREOTACTIC RADIOSURGERY IS the first widely used “biological surgery.” The opportunity for surgeons working with radiation oncologists and medical physicists to affect cell structures with both direct and indirect vascular effects has transformed neurosurgery. As a minimal access surgical approach, it fits well into the patient goals of functional preservation, risk reduction, and cost-effectiveness. Longer-term results have been published for many indications. For many disorders, it may be better to “leave the tumor in rather than take it out.” Radiosurgery has had an impact on the management of patients with vascular malformations, all forms of cerebral neoplasia, and selected functional disorders such as trigeminal neuralgia and tremor. It can be performed alone when lesion volume is not excessive or as part of a multimodality strategy with resection or endovascular surgery. Epilepsy, behavioral disorders, and other novel indications are the topics of current investigation. The combination of high-resolution imaging, high-speed computer workstations, robotics, patient fixation techniques, and radiobiological research has put radiosurgery into the practice of almost all neurosurgeons.

Central neurocytoma: a clinical, radiological and pathological study of nine cases

PURPOSE

Central neurocytoma is a rare intraventricular brain tumor that affects young adults and presents with increased intracranial pressure secondary to obstructive hydrocephalus. Typically, it has a favorable prognosis after adequate surgical intervention, but in some cases the clinical course is more aggressive. In this report, we describe the diagnosis and treatment of central neurocytoma in a series of patients at our institution.

PATIENTS AND METHODS

Our series of nine patients (M:F=2:7, mean age, 28.2 years) with ventricular tumors showed typical radiological, histologic and immunohistochemical features of central neurocytoma. Most patients received craniotomy with removal of the tumor through transcallosal or transcortical approach. The surgical and histopathologic data of these patients were reviewed and analyzed.

RESULTS

The prognosis is generally favorable. Although most patients were alive and well at the last follow-up, two developed recurrence. Typical histologic features of recurrent neurocytoma include high proliferative activity (MIB-1 labeling index: 2.0-6.8%), prominent vascular proliferation and remarkable synaptophysin expression. Two patients (non-recurrent) died during follow-up due to sepsis or central failure. The MIB-1 labeling indices were as high as 2.2-5.4% for these two patients.

CONCLUSION

Although central neurocytoma is generally a benign neoplasm, some variant forms of recurrence are also present. Complete resection provides favorable long-term prognosis in most cases. Recurrent tumors are often local and the patients seem to recover well after a second resection followed by radiotherapy. Histologic features such as tumor proliferation (MIB-1 labeling index), vascular proliferation, and synaptophysin expression are often prominent in the recurrent tumor. We recommend that these histologic features be considered for tumor recurrence during treatment and follow-up of these patients.