Upfront Gamma Knife Surgery for Giant Central 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.

Clinical Outcomes and Prognostic Analysis of 101 Patients of Central Neurocytoma: A 10-Year Treatment Experience at a Single Institution

Objective

Central neurocytoma (CN) is a rare type of tumor that currently lacks an optimal treatment protocol. This study aimed to explore the clinical outcomes of CN in a cohort of 101 patients and identify prognostic factors associated with multiple treatment modalities.

Methods

This monocentric study retrospectively analyzed the clinical data of 101 CN patients who underwent surgical resection. The patients were followed up, and their overall survival (OS) and progression-free survival (PFS) were calculated.

Results

For the entire cohort, the 5- and 10-year OS rates were 88.7% and 82.8%, respectively, and the 5- and 10-year PFS rates were 86.5% and 64.9%, respectively. Of the 82 (81.19%) patients with CN who underwent gross total resection (GTR), 28 (28/82, 34.1%) also received radiotherapy (RT). Of the 19 (18.81%) patients with CN who underwent subtotal resection (STR), 11 (11/19, 57.9%) also received RT or stereotactic radiosurgery (SRS). Compared to STR, GTR significantly improved the 5-year OS (92.4% vs. 72.4%, P=0.011) and PFS (92.4% vs. 60.4%, P=0.009) rates. Radiotherapy did not affect OS in the GTR group (p=0.602), but it had a statistically significant effect on OS in the STR group (P<0.001). However, the OS (P=0.842) and PFS (P=0.915) in the STR plus radiotherapy group were comparable to those in the GTR alone group. Compared to STR alone, STR plus radiotherapy improved the 5-year PFS rate from 25% to 75% in patients with atypical CN (P=0.004). Cox regression models and a competing risk model showed that the removal degree and radiotherapy were independent prognostic factors for survival. With improvements in modern radiotherapy techniques, severe radiotherapy toxicity was not observed.

Conclusion

Our findings support the use of GTR whenever possible. Radiotherapy can improve the prognosis of patients who undergo STR, especially in atypical CNs having a higher tendency to relapse. Close imaging follow-up is necessary. Our findings will help clinicians to select optimal, individualized treatment strategies to improve OS and PFS for patients with CN.

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.

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.

Tumor control of third ventricular central neurocytoma after gamma knife radiosurgery in an elderly patient: A case report and literature review

RATIONALE

Central neurocytoma is rare benign tumor that occurs in high probability in young adults in the lateral ventricle. Herein, we report an unusual case of an elderly woman who was diagnosed with central neurocytoma isolated to the third ventricle. This deeply located tumor was effectively treated using gamma knife radiosurgery (GKR).

PATIENT CONCERNS

A 79-year-old woman was admitted to hospital with gait disturbance and cognitive dysfunction.

DIAGNOSIS

Brain magnetic resonance imaging (MRI) revealed a homogenously enhancing multilobulated mass in the posterior third ventricle measuring 1.8 cm in size. The tumor was diagnosed as a central neurocytoma isolated to the third ventricle.

INTERVENTIONS

Neuronavigation-guided endoscopic third ventriculostomy and biopsy were performed. One week following surgery, GKR was performed using a prescribed dose of 14 Gy with 50% isodose lines, and a target volume of 1.62 cc.

OUTCOMES

Three months after GKR, brain MRI revealed a decrease in the size (to 1.4 cm) of the multilobulated strong enhancing mass in the posterior third ventricle, and the patient's symptom of confusion was improved.

LESSONS

Previous studies have reported that tumors in unusual locations, such as those isolated to the third ventricle, are different according to age, either in young children or elderly individuals. Although complete surgical resection is an effective treatment for central neurocytoma, it is often difficult to approach these tumors through surgery. GKR could, therefore, be an alternative primary treatment option for deeply located central neurocytomas in elderly patients.

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.