Atypical Central Neurocytoma: An Investigation of Prognostic Factors.

OBJECTIVE: Central neurocytoma is a rare nervous tissue benign neoplasm. A subset of central neurocytoma has unfamiliar aggressive tendency: so-called atypical central neurocytoma (ACN). This retrospective study aims to analyze the prognostic factors and the impact of various therapy tools on atypical central neurocytoma. METHODS: Twenty-two patients diagnosed with ACN between January 2009 and March 2018 were included. Data collected included the patient's age, gender, tumor location, presenting symptoms, and treatment received. Patients were followed up to detect recurrence and to assess survival. RESULTS: Median overall survival was 57 months, with a 5-year survival of 35%. Better survival was observed for patients <35 years old (66 vs. 47 months; P = 0.061) and patients with gross total resection over subtotal resection or biopsy (76, 45, and 22 months, respectively; P < 0.0001). Patients with a tumor located in the posterior half of the lateral ventricle had better survival, with no statistical significance (P = 0.053). Multivariate analysis showed prognostic significance with the extent of resection (P = 0.000). Progression-free survival ranged from 6 to 82 months, with a median value of 38 months and showed a significant relation with subtotal resection compared with biopsy (P = 0.006). Recurrence was less in patients who received radiotherapy and was statistically significant (P = 0.007). CONCLUSIONS: Long-term survival is possible for patients with atypical central neurocytomas treated with surgery and postoperative radiation. Multivariate analysis confirmed that gross total resection was an independent prognostic factor for survival. Adjuvant radiotherapy reduces tumor recurrence, especially after incomplete surgery.

Clinico-radiological characteristics, histo-pathological features and long-term survival outcomes in central neurocytoma: A single-institutional audit.

Central neurocytoma is a rare benign brain tumor that typically arises from the subependymal lining of the lateral ventricles in young adults and is generally associated with excellent survival following neurosurgical excision alone. This is a retrospective clinical audit of biopsy-proven neurocytoma registered between 2004 and 2019 at a single institution in India. All time-to event outcomes were analyzed using Kaplan-Meier method and compared with the log-rank test. Any p-value <0.05 was considered statistically significant. A total of 66 patients with neurocytoma were included in the descriptive analysis. Median age of study cohort was 31 years with equitable gender ratio. Majority (83%) of tumors were intraventricular, lateral ventricle being the commonest location. Following maximal safe resection, patients were generally kept on close clinico-radiological surveillance. Most patients (80%) had typical World Health Organization (WHO) grade II neurocytoma with remaining 20% showing histological atypia and/or high-grade features. Outcome analysis was restricted to 35 patients with relevant treatment details and adequate follow-up information. Six patients experienced recurrent/progressive disease with 2 documented deaths. At a median follow up of 52 months, 5-year Kaplan-Meier estimates of progression-free survival and overall survival were 93.3% and 96.8% respectively. Three patients developed delayed recurrence (>5-years after initial diagnosis) underscoring the importance of long-term follow-up. Atypical/high-grade histology was associated with inferior survival that may stand to benefit with upfront adjuvant radiotherapy. This represents the largest single-institution series of central neurocytoma and demonstrates excellent outcomes with adequate surgical resection alone, reserving radiotherapy for large residual tumor, recurrent disease, and/or atypical high-grade histology.

Relative survival of patients with central neurocytoma.

To compensate for the lack of disease-specific survival data in the study by Rae et al., the US National Cancer Data Base was used to identify patients with histologically confirmed central neurocytoma from 2004 to 2013 based on the same inclusion criteria and relative survival analysis was performed. A total of 781 patients were identified. The 5-year overall survival (OS) for the overall cohort was 87.2%, and the 5-year survival relative to the expected survival of an age-, and gender-matched US standard population was 89.5% (95% CI 86.6%-91.9%). In summary, the relative survival analysis presented here indicates that central neurocytoma was a component of the cause of mortality in the affected US population.

The role of proton beam therapy in central neurocytoma: A single-institution experience.

PURPOSE: Central neurocytomas (CNs) are rare World Health Organization grade II tumors managed with surgery and radiation therapy. We report our experience in managing CN with proton beam therapy (PBT) when radiation therapy was used. METHODS AND MATERIALS: We identified 61 patients with pathologically diagnosed CN treated at our institution between 1996 and 2016, of which 24 met inclusion criteria. Patient, tumor, and treatment characteristics are reported in context of progression-free survival and treatment-related adverse events. RESULTS: Of 24 patients identified, median age at diagnosis was 21 years (range, 14-60). Median maximal tumor diameter was 4.5 cm (range, 1.4-6.8). Eighteen (75%) patients underwent upfront surgery alone. Sixteen (67%) patients received adjuvant or salvage PBT at a median dose of 54 Gy (relative biological effectiveness). Median follow-up was 56 months. Median progression-free survival (PFS) was 61 months. Eleven patients had disease progression with median time to progression of 22 months. Of the 5 patients with gross total resection, 4 experienced local recurrence and had MIB-1 >4% (range, 4.5-30). There was improved PFS with addition of PBT to definitive surgery (log-rank, P = .06); there was no disease progression to date. In patients who experienced disease recurrence/progression, MIB-1 <4% was associated with improved PFS (log-rank, P = .007). All patients tolerated PBT well with toxicities typical for cranial irradiation and with no grade 3+ toxicities. CONCLUSION: In our cohort, CN with elevated MIB-1 index were at increased risk for disease progression. However, adjuvant radiation therapy appears to effectively prevent failure. PBT toxicities appear to be comparable to if not less than published photon experiences.

Central neurocytoma: Clinical characteristics, patterns of care, and survival.

PURPOSE: To investigate clinical characteristics and patterns of care among patients with central neurocytomas in a large cohort of patients. METHODS: The National Cancer Database (NCDB) was queried to identify patients with biopsy confirmed neurocytoma from 2004 to 2015. Patterns of care were described and univariable and multivariable models were performed to investigate the impact of prognostic factors on overall survival. RESULTS: Among 223,404 patients with brain tumors in the NCDB, 868 patients were diagnosed with biopsy-proven neurocytoma and analyzed (0.4% or approximately 75 patients annually). Median age at diagnosis was 31 years and median tumor size was 4-5 cm. Diagnosis was similar between male (49.5%) and female (50.5%). Regarding location, 622 (72%) tumors were intraventricular, 168 (19%) were extra-ventricular, and 78 (9%) overlapping or unspecified. Five-year overall survival among all patients was 89%. On multivariable analysis tumor location, extent of resection, and use of radiation, were not predictive for improved survival (each p > 0.05); however, patient age (p < 0.001), WHO grade (p < 0.001), and medical comorbidity scores (p = 0.002) were independently associated with overall survival. CONCLUSION: Patients with central neurocytoma often present as young adults with sizable tumor burden and are well managed with surgery alone. Considering their favorable survival, efforts to improve tumor control should be carefully weighed against the long-term risks associated with adjuvant therapy like radiation.

Patterns of care and survival outcomes in patients with an extraventricular neurocytoma: An individual patient data analysis of 201 cases.

INTRODUCTION:: Extraventricular neurocytoma is a rare neuronal tumor arising outside the ventricles. However, because of its rarity, its optimum treatment remains undefined. MATERIALS AND METHODS: We intended to perform an individual patient data analysis to examine the patterns of care and prognostic factors involved in the treatment of extraventricular neurocytomas. PubMed, SCOPUS, and Google Scholar were searched with the following MeSH terms: "Neurocytoma, Extra ventricular neurocytoma, Spinal neurocytoma AND treatment, Survival" to find all possible publications pertaining to EVN. RESULTS: From 108 publications, we retrieved 201 patients of extraventricular neurocytoma. Their median age was 30 years (range: 0.6-78 years). Sixty seven patients were in the pediatric (age ≤20 years) age group. There was a bimodal age distribution. Surgical details were available for 132 cases, and 51.5% underwent a gross total resection whereas 41.7% underwent a subtotal resection. Adjuvant radiation was used in 40% cases. For the entire cohort, the median progression free survival was 77 months (53.3-100.7). However, we could not find an impact of any of the prognostic factors on survival. CONCLUSION: An extraventricular neurocytoma is a very rare disease with varied presentations and different sites of origin. Gross total resection remains the standard of care. Adjuvant radiation may be used for salvage. However, radiation therapy after subtotal resection of an atypical neurocytoma may be administered.

Clinical Features, Treatment, and Long-term Outcomes of Central Neurocytoma: A 20-Year Experience at a Single Center.

OBJECTIVE: Central neurocytoma (CN) is a rare central nervous system tumor the optimal management strategy of which remains controversial because of their rarity. Detailed information on CN is necessary to establish optimal management strategies. The purpose of this study was to show the clinical features, treatments, and long-term clinical outcomes of CN. METHODS: A total of 63 patients with CN were surgically treated between 1995 and 2016 at West China Hospital. All pathologically proven CN cases were identified. Epidemiologic characteristics, clinical features, imaging features, functional outcomes, overall survival, and progression-free survival according to multimodal treatments were reviewed retrospectively. RESULTS: There were 29 males and 34 females, with a median age of 29 years (range, 15-58 years). Thirty-four patients underwent gross total resection (GTR) and 29 patients underwent subtotal resection (STR). The surgical approaches to CNs in this study included a transcortical approach (39 cases) and an interhemispheric transcallosal approach (24 cases). There were no differences in functional outcomes or initial extent of resection according to the surgical approach used. The extent of resection was GTR in 34 patients (54.0%), and STR in 29 patients (46.0%). At the median follow-up of 74 months (range, 6-205 months), the actuarial 5-year and 10-year overall survival were 93.3% and 85.4%. At the last follow-up, 8 patients had experienced tumor progression. The 5-year and 10-year progression-free rate was 73.4% and 57.5%. The initial extent of resection and multimodal treatment was not related to overall survival; however, the actuarial local control rate differed significantly according to the initial extent of resection and multimodal treatment. CONCLUSIONS: CN is a rare type of World Health Organization grade II primary brain tumor with a tendency to recur. Complete resection of CNs with maximal safety remains the primary treatment to minimize local progression. Adjuvant radiotherapy should be considered in patients receiving incomplete resection. The long-term clinical outcomes of CN after multimodal treatment seem to be satisfactory.

Clinical characteristics and prognostic factors of brain central neurocytoma.

BACKGROUND & AIMS: This study is designed for the clinical characteristics and prognostic factors of central neurocytoma (CN). METHODS: CN patients from 2004 to 2012 were enrolled from the Surveillance Epidemiology and End Results (SEER) data. Clinical characteristics including age, sex, race, tumor size, tumor number, surgery, and radiation therapy were summarized. Univariate and multivariate analysis were performed to explore the prognostic factors of CN. RESULTS: CN tended to be borderline malignant and single lesion. Compared with other brain tumor (NCN), Patients with CN (CNs) were more likely to be female, young, and non-white race. Surgery was the primary treatment of CN. Univariate and Multivariate analysis indicated tumor number and surgery were both independent prognostic factors of CN (P < 0.05). Unifocal CNs had a lower mortality risk than multifocal ones (HR 0.167, 95% CI 0.052-0.537), surgery significantly reduced the death risk of CNs (HR 0.284, 95% CI 0.088-0.921). CONCLUSIONS: CN tend to be borderline malignant, single lesion, operated on. Most CNs are female and younger. single lesion and surgery are the independent positive prognostic factors of CN.

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.

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.

Role of adjuvant radiation in the management of central neurocytoma: Experience from a tertiary cancer care center of India.

BACKGROUND AND OBJECTIVE: Neurocytoma (NC) is a rare benign neuronal tumor. A complete excision remains curative for most of these tumors, but atypical histology and extra-ventricular location often necessitates adjuvant therapy. We intended to explore the clinico-pathological features and treatment outcome in patients of NC in our institute. MATERIALS AND METHODS: Medical records were reviewed and data collected on NC over a 6-year period (2006-2012) from the departmental archives. Disease free survival (DFS) was analyzed by Kaplan-Meier method. RESULTS: A total of 18 patients met the study criteria. Fourteen patients had intra-ventricular neurocytoma (IVNC), right lateral ventricle being the most common site of origin. Gross total resection and near total resection were achieved in eight cases each whereas tumor decompression and biopsy could be done in two cases. On post-operative histopathological examination, eight patients were found to have atypical NC while 10 patients had typical NC. All patients underwent adjuvant radiation. The median dose of post-operative radiation was 56 Gy. All patients were alive at their final follow-up. One patient had both clinical and radiological evidence of local relapse. In the evaluable patients (n = 18), after a median follow-up of 35 months the DFS rate at 2 years and 3 years are 100% and 83% respectively. CONCLUSION: Use of adjuvant radiation to a total dose of 56 Gy enhances the local control and achieves superior survival in patients of NC. Use of 3D conformal planning techniques may help us to achieve better therapeutic ratio in patients with NC.

Long-term outcomes of adjuvant radiotherapy after surgical resection of central neurocytoma.

BACKGROUND AND PURPOSE: The role of adjuvant radiotherapy for central neurocytomas (CNs) is not clear. Therefore, we aimed to examine the clinical outcomes of treating histologically confirmed CNs with adjuvant RT after surgical resection. MATERIAL AND METHODS: Sixty-three CN patients were retrospectively evaluated: 24 patients underwent gross total resection (GTR); 28, subtotal resection (STR); 9, partial resection (PR), and 2, biopsy (Bx). They underwent adjuvant RT after surgery (median dose, 54 Gy). RESULTS: The median follow-up was 69 months (15-129 months). The 5-year overall survival (OS) and 5-year progression-free survival (PFS) were 94.4% and 95% after GTR + RT, 96.4% and 100% after STR + RT, and 100% and 90.9% after PR + RT. Only three patients had tumor recurrence: at the primary site at 30 and 24 months in two GTR + PR patients, and dissemination to the spinal cord at 75 months in one STR + RT patient. Thirty-eight (63.3%) patients experienced late neurotoxicity (28, grade 1; 7, grade 2; 3, grade 3). Short-term memory impairment was the most common toxicity. CONCLUSIONS: RT after incomplete resection (IR) led to OS and PFS comparable to those for GTR. Considering the excellent outcomes and limited late toxicity, adjuvant RT maybe a good option for CN patients who undergo IR.

Intraventricular neurocytomas: a systematic review of stereotactic radiosurgery and fractionated conventional radiotherapy for residual or recurrent tumors.

To determine optimal treatment for recurrent or residual intraventricular neurocytomas (IVNs), a systematic review of PubMed and EMBASE was conducted comparing fractionated conventional radiotherapy (FCRT) versus stereotactic radiosurgery (SRS). Inclusion criteria included histological IVN documentation, at least 6 months of follow-up observation and described dose of FCRT or SRS administered. Descriptive statistical and Kaplan-Meier analyses were performed. The literature search yielded 451 articles. Sixteen studies met inclusion criteria. The local tumor control proportion was 93% and 88% in the SRS and FCRT subgroups, respectively. The relative risk (RR) of local recurrence was 0.57 less (95% CI: 0.21-1.57; log-rank p=0.85) and the RR of all-cause mortality was 0.23 less (95% CI: 0.05-1.05; log-rank p=0.22) in SRS subgroup compared to the FCRT subgroup but did not reach statistical significance. Recurrence was significantly associated with presence of histological atypia (log-rank p<0.001). Severe complications were lower in SRS subgroup (5.5% versus 7.5%, p=0.74); however, distant tumor recurrence was slightly lower in the FCRT subgroup (1.5% versus 5.5%, p=0.24). The role of SRS or FCRT in the management of residual or recurrent IVNs will continue to depend on the balance between the risks and benefits of SRS and FCRT until better quality data are available.

Outcomes after surgery for central neurocytoma: results of a French multicentre retrospective study.

OBJECTIVE: Central neurocytoma (CN) is a rare intraventricular tumour. Surgery has been highly recommended for CN, although it entails a significant chance to harm the patient. We aimed to provide new data that would support surgical decision-making and optimise patient information about outcomes after surgery. METHOD: Under the auspices of the French Society of Neurosurgery, we conducted a multi-institutional database search in 23 academic hospitals. In all, we reviewed the relevant clinical and radiological data of 82 patients who were operated on for CN between 1984 and 2008, and had their diagnosis confirmed by central pathological review. RESULTS: The median follow-up was 61 months (range, 6-96 months). Gross total resection (GTR) was achieved in 48 % of the patients, and subtotal resection (STR) in 52 %. The 5-year overall survival rate was 93.8 % (95 % CI, 93.7-93.9). The 5-year progression-free survival rate was 92.1 % (95 % CI, 91.90-92.2) in patients who underwent GTR, compared with 55.3 % (95 % CI, 55.1-55.5) in patients who had STR (p = 0.01). The overall perioperative complication rate was 66 %. The main causes of postoperative disability were some degree of postoperative paresis and/or aphasia (39 %), memory difficulties (29 %) and temporary hydrocephalus (26 %). GTR was not associated with an increased rate of postoperative complications compared with STR. At last follow-up, Karnofsky Performance Score was at least equal to 80 for 90.6 % of the tested patients. CONCLUSION: Our series emphasised that maximal surgical resection of CNs offers favourable benefit-risk ratio. These data are of importance to properly counsel patients regarding expected outcomes, and to plan relevant preoperative and postoperative investigations like language and memory function evaluation.

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.

Atypia predicting prognosis for intracranial extraventricular neurocytomas.

OBJECT: The literature, at present, provides limited information about extraventricular neurocytomas (EVNs) and is almost exclusively composed of case reports or small case series. Treatment for EVNs has largely been guided by results from central neurocytoma outcome studies. The authors present an analysis of all reported intracranial EVN cases to establish if tumor histopathological features can substratify EVN into groups with differing prognosis and help guide treatment decisions. METHODS: The authors identified studies reporting histology, treatment modality, and outcomes for patients with intracranial EVN. The rates of recurrence and survival for patients were compared using Kaplan-Meier analysis. Atypical tumors, defined by MIB-1 labeling index exceeding 3% or atypical histological features, were compared with typical tumors, and patients 50 years of age or older were compared with those younger than 50 years of age. RESULTS: Eighty-five patients met the inclusion criteria, and 27% of them had an atypical histology. Typical EVNs had a better prognosis than atypical EVNs after primary treatment, with a 5-year recurrence rate of 36% compared with 68% (p < 0.001), and a 5-year mortality rate of 4% compared with 44%, respectively (p < 0.001). Age younger 50 years was associated with a better prognosis than age equal to or greater than 50 years, with a 5-year recurrence rate of 33% and 74%, respectively (p < 0.001), and a 5-year mortality rate of 4% and 52%, respectively (p < 0.001). Multivariate analysis demonstrated that atypical EVNs carried significantly increased risk for recurrence (hazard ratio [HR] 4.91, p < 0.001) and death (HR 22.91, p < 0.01). Gross-total resection was superior to subtotal resection (STR) alone in tumor control rates for typical EVNs (95% and 68%, p < 0.05), and there was a trend for adjuvant external-beam radiotherapy to benefit STR. There was suggestion of similar trends in patients with atypical EVNs. CONCLUSIONS: There are at least 2 distinct histological subtypes of EVN, with different prognostic significances. Atypia or MIB-1 labeling index greater than 3% is a significant predictor of poor prognosis for EVNs. Complete resection or more aggressive attempts at providing adjuvant therapy following STR appear to improve the prognosis for patients with EVNs. Although the authors' results are informative, there are limitations to their analysis. Given the relatively modest total number of cases reported, as well as the nature of the disaggregated analysis, the authors were not able to use formal meta-analytical methods to limit the impact of between center heterogeneity. Additionally, they were not able to control for individual differences in data analysis and presentation across the different studies included in their analysis.

Emotion and cognitive function assessment of patients with central neurocytoma resection through transcortical frontal approach: a 5-year postoperative follow-up study.

BACKGROUND: Central neurocytoma accounts for 0.1% of primary brain tumor that often occurs in young adults. Surgery is the main treatment for central neurocytoma and the rate of 5-year survival reaches up to over 90%. This study aimed to assess the effect of transcortical frontal approach to surgical resection of central neurocytoma on emotion and cognitive function 5 years after surgery. METHODS: Telephone following-up visits were used in this study. By means of neuropsychological testing, assayed emotion, memory and abstract thinking ability of 18 patients undergoing central neurocytoma resection by transcortical frontal approach for 5 years or more, with another 21 normal cases as control group were enrolled. The data were analyzed statistically by paired t test with SPSS11.5. RESULTS: Patients whose central neurocytoma was removed by transcortical frontal approach were not affected on calculating ability 5 years after operation while ability of memory declined sharply (P = 0.000), the older, the more sharply (P = 0.036). Ability of abstract thinking was significantly reduced (P = 0.000), the older, the more significantly as well (P = 0.012); additionally, anxiety and depression occurred in patients rather more than those of control group (P = 0.000), especially cognitive impairment. CONCLUSIONS: Transcortical frontal approach for surgical resection of central neurocytoma has certain long-term influence on patients' life quality, vulnerable to anxiety, depression and cognitive impairment, the severity of which was correlated to age. Therefore, improving surgical approach will be of value for better long-term life quality of patients.

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.

Central neurocytoma: management recommendations based on a 35-year experience.

PURPOSE: To examine the outcomes of patients with histologically confirmed central neurocytomas. METHODS AND MATERIALS: The data from 45 patients with central neurocytomas diagnosed between 1971 and 2003 were retrospectively evaluated. Various combinations of surgery, radiotherapy (RT), and chemotherapy had been used for treatment. RESULTS: The median follow-up was 10.0 years. The 10-year overall survival and local control rate was 83% and 60%, respectively. Patients whose tumor had a mitotic index of <3 (per 10 high-power fields) experienced a 10-year survival and local control rate of 89% and 74%, respectively, compared with 57% (p = 0.040) and 46% (p = 0.14) for patients with a tumor mitotic index of > or =3. The 10-year survival and local control rate was 90% and 74% for patients with typical tumors compared with 63% (p = 0.055) and 46% (p = 0.41) for those with atypical tumors. A comparison of gross total resection with subtotal resection showed no significant difference in survival or local control. Postoperative RT improved local control at 10 years (75% with RT vs. 51% without RT, p = 0.045); however, this did not translate into a survival benefit. No 1p19q deletions were found in the 19 tumors tested. CONCLUSION: Although the overall prognosis is quite favorable, one-third of patients experienced tumor recurrence or progression at 10 years, regardless of the extent of the initial resection. Postoperative RT significantly improved local control but not survival, most likely because of the effectiveness of salvage RT. For incompletely resected atypical tumors and/or those with a high mitotic index, consideration should be given to adjuvant RT because of the more aggressive nature.