Risk Factors of Persistent Hydrocephalus in Children with Brain Tumor: A Retrospective Analysis

Diagnosis of pediatric central nervous system tumors using methylation profiling of cfDNA from cerebrospinal fluid

Pediatric central nervous system tumors remain challenging to diagnose. Imaging approaches do not provide sufficient detail to discriminate between different tumor types, while the histopathological examination of tumor tissue shows high inter-observer variability. Recent studies have demonstrated the accurate classification of central nervous system tumors based on the DNA methylation profile of a tumor biopsy. However, a brain biopsy holds significant risk of bleeding and damaging the surrounding tissues. Liquid biopsy approaches analyzing circulating tumor DNA show high potential as an alternative and less invasive tool to study the DNA methylation pattern of tumors. Here, we explore the potential of classifying pediatric brain tumors based on methylation profiling of the circulating cell-free DNA (cfDNA) in cerebrospinal fluid (CSF). For this proof-of-concept study, we collected cerebrospinal fluid samples from 19 pediatric brain cancer patients via a ventricular drain placed for reasons of increased intracranial pressure. Analyses on the cfDNA showed high variability of cfDNA quantities across patients ranging from levels below the limit of quantification to 40 ng cfDNA per milliliter of CSF. Classification based on methylation profiling of cfDNA from CSF was correct for 7 out of 20 samples in our cohort. Accurate results were mostly observed in samples of high quality, more specifically those with limited high molecular weight DNA contamination. Interestingly, we show that centrifugation of the CSF prior to processing increases the fraction of fragmented cfDNA to high molecular weight DNA. In addition, classification was mostly correct for samples with high tumoral cfDNA fraction as estimated by computational deconvolution (> 40%). In summary, analysis of cfDNA in the CSF shows potential as a tool for diagnosing pediatric nervous system tumors especially in patients with high levels of tumoral cfDNA in the CSF. Further optimization of the collection procedure, experimental workflow and bioinformatic approach is required to also allow classification for patients with low tumoral fractions in the CSF.

Choroid plexus mast cells drive tumor-associated hydrocephalus

Tumor-associated hydrocephalus (TAH) is a common and lethal complication of brain metastases. Although other factors beyond mechanical obstructions have been suggested, the exact mechanisms are unknown. Using single-nucleus RNA sequencing and spatial transcriptomics, we find that a distinct population of mast cells locate in the choroid plexus and dramatically increase during TAH. Genetic fate tracing and intracranial mast-cell-specific tryptase knockout showed that choroid plexus mast cells (CPMCs) disrupt cilia of choroid plexus epithelia via the tryptase-PAR2-FoxJ1 pathway and consequently increase cerebrospinal fluid production. Mast cells are also found in the human choroid plexus. Levels of tryptase in cerebrospinal fluid are closely associated with clinical severity of TAH. BMS-262084, an inhibitor of tryptase, can cross the blood-brain barrier, inhibit TAH in vivo, and alleviate mast-cell-induced damage of epithelial cilia in a human pluripotent stem-cell-derived choroid plexus organoid model. Collectively, we uncover the function of CPMCs and provide an attractive therapy for TAH.

Total diagnostic interval in children with brain tumours in a middle-income country: national experience from Serbia

PURPOSE

The aim was to evaluate the total diagnostic interval (TDI) and presenting complaints in children with brain tumours in Serbia.

METHODS

This study retrospectively analysed 212 children aged 0-18 years newly diagnosed with brain tumours in two tertiary centres from mid-March 2015 to mid-March 2020 covering virtually all children with brain tumours in Serbia. TDI was calculated as the difference between the date of diagnosis and the date of symptom onset presented as a median in weeks. This variable has been evaluable for 184 patients.

RESULTS

Overall TDI was 6 weeks. TDI was significantly longer in patients with low-grade tumours (11 weeks) than in patients with high-grade tumours (4 weeks). Children with the most frequent complaints (headache, nausea/vomiting and gait disturbance) were more likely to be diagnosed sooner. Patients with a single complaint had significantly longer TDI (12.5 weeks) contrasted to patients with multiple complaints (5 weeks).

CONCLUSION

TDI with a median of 6 weeks is similar to other developed countries. Our study supports the view that low-grade tumours will present later than high-grade tumours. Children with the commonest complaints and children with multiple complaints were more likely to be diagnosed sooner.

A nomogram for predicting post-operative hydrocephalus in children with medulloblastoma

Post-operative hydrocephalus is common among children with medulloblastoma after initial tumor resection. This study aimed to establish a novel model for predicting the development of post-operative hydrocephalus in children with medulloblastoma. Only pediatric patients who received initial medulloblastoma resection at Beijing Tiantan Hospital between January 2018 and May 2021 were included in this study. The potential risk factors associated with post-operative hydrocephalus were identified based on multivariate logistic regression and the nomogram. Receiver operating characteristic (ROC) curve were used to evaluate the performance of the nomogram model based on an independent cohort of medulloblastoma patients who underwent surgery from June 2021 to March 2022. A total of 105 patients were included in the primary cohort. Superior invasion (P = 0.007), caudal invasion (P = 0.025), and intraventricular blood ≥ 5 mm (P = 0.045) were significantly related to the development of post-operative hydrocephalus and thus were assembled into the nomogram model. The model accurately predicted post-operative hydrocephalus based on the calibration curve. The area under the ROC curves for the primary and validation cohorts was 0.849 and 0.855, respectively. In total, the nomogram we developed may aid clinicians in assessing the potential risk of pediatric patients with MB developing post-operative hydrocephalus, especially those who would otherwise not have received a diversionary procedure at presentation.

Predictive factors for persistent postoperative hydrocephalus in children undergoing surgical resection of periventricular tumors

Objective

The aim of this study is to identify the factors predicting persistent hydrocephalus after periventricular tumor resection in children and assess the need and efficacy of perioperative cerebrospinal fluid (CSF) intervention.

Methods

We performed a retrospective analysis of pediatric patients who underwent resection surgery of a periventricular tumor between March 2012 and July 2021 at the Department of Neurosurgery in Zhujiang Hospital of South Medical University. Demographic, radiographic, perioperative, and dispositional data were analyzed using univariate and multivariate models.

Results

A total of 117 patients were enrolled in our study. Incidence of postoperative persistent hydrocephalus varied with tumor pathology (p = 0.041), tumor location (p = 0.046), surgical approach (p = 0.013), extension of resection (p = 0.043), tumor volume (p = 0.041), preoperative Evan's index (p = 0.002), and preoperative CSF diversion (p = 0.024). On logistic regression, posterior median approach (OR = 5.315), partial resection (OR = 20.984), volume > 90cm³ (OR = 5.768), and no preoperative CSF diversion (OR = 3.661) were independent predictors of postoperative persistent hydrocephalus. Preoperative Evan's index is significantly correlated with tumor volume (p = 0.019). Meanwhile, the need for preoperative CSF drainage in patients in this cohort was significantly correlated with tumor location (p = 0.019).

Conclusion

Tumor pathology, location, surgical approach, the extension of resection, tumor volume, preoperative Evan's index, and preoperative CSF diversion were considered to be predictive factors for postoperative persistent hydrocephalus. Notably, posterior median approach, partial resection, and tumor volume > 90cm³, without preoperative CSF diversion, were identified as independent risk factors for persistent postoperative hydrocephalus. Preoperative identification of children at risk of developing persistent postoperative hydrocephalus would avoid delays in planning the cerebrospinal fluid diversion. Active and effective preoperative hydrocephalus intervention in children with periventricular tumors is beneficial to reduce the incidence of persistent hydrocephalus and ventriculoperitoneal shunt surgery after resection.

Incidence and Risk Factors for Necessitating Cerebrospinal Fluid Diversion Following Medulloblastoma Surgery in Children

BACKGROUND

There are insufficient data on pediatric patients with medulloblastoma who require cerebrospinal fluid (CSF) diversion following resection. Therefore, this study aimed to determine the incidence and the characteristics associated with it in this subset of patients.

METHODS

We conducted a single-center, retrospective, observational cohort study of patients aged 18 years or less who underwent medulloblastoma resection at our department between 2010 and 2021. The primary outcome was the incidence of CSF diversion surgery required after resection. Participant demographics, tumor biology, and interventions were analyzed using univariate- and multivariate-adjusted models.

RESULTS

Of the 183 patients admitted to our department, 131 (71.6%) participated in this study. The incidence of permanent CSF diversion was 26.0% (95% confidence interval [CI]: 18.7 to 34.3). Factors independently associated with requirement of permanent CSF diversion were medulloblastoma volume >46.4 cm³ (odds ratio [OR]: 2.919, 95% CI: 1.191 to 7.156) and CSF channel invasion (OR: 2.849, 95% CI: 1.142 to 7.102). The duration of manifestation may be a covariate of tumor volume with increased risk of requirement for permanent CSF diversion (OR: 1.006, 95% CI: 1.000 to 1.013), and tumor volume may be a predictor in patients who underwent subtotal resection (OR: 4.900, 95% CI: 0.992 to 24.208, P = 0.05). Finally, patients who required permanent CSF diversion were divided according to medulloblastoma molecular subgroups, and no significant differences were found.

CONCLUSION

We report major predictive factors for permanent CSF diversion surgery in patients with medulloblastoma. Our study suggests that the presence of postresection hydrocephalus is not high enough to warrant permanent, prophylactic CSF diversion in all patients.

Contribution of tumor characteristics and surgery-related factors to symptomatic hydrocephalus after posterior fossa tumor resection: a single-institution experience

OBJECTIVE

Pediatric patients are at risk of persistent hydrocephalus after posterior fossa tumor resection. The relationship between surgery-related factors and postoperative symptomatic hydrocephalus has not been elucidated. The objective of this study was to analyze features influencing postoperative hydrocephalus in Chinese children.

METHODS

The authors retrospectively evaluated 197 patients younger than 15 years of age who underwent posterior fossa tumor resection at their institution from January 2015 to June 2021. The outcome was whether children underwent CSF diversion within 6 months of resection. Preoperative characteristics, surgery-related factors, and postoperative features were included to identify independent prognosticators. A new logistic model containing independent prognosticators was developed and compared with the modified Canadian Preoperative Prediction Rule for Hydrocephalus (mCPPRH).

RESULTS

In this study, 30 patients (15.2%) underwent CSF diversion within 6 months after tumor resection. Tumor location and consistency, intracranial or spinal tumor metastasis determined by perioperative cerebral and spinal MRI, intraoperative blood loss, ventricular blood as determined on postoperative CT, and pathology were statistically significant variables in the univariate analysis. The only two independent predictors of postoperative symptomatic hydrocephalus were tumor metastasis (OR 3.463, 95% CI 1.137-10.549; p = 0.029) and postoperative ventricular blood (OR 4.212, 95% CI 1.595-11.122; p = 0.004). The final logistic model comprising tumor metastasis and postoperative ventricular blood was found to have better discrimination than the mCPPRH.

CONCLUSIONS

Tumor characteristics and surgery-related features were associated with postoperative symptomatic hydrocephalus. Tumor metastasis and postoperative ventricular blood were found to be important prognosticators of persistent hydrocephalus.

Risk factors for postresection shunting in children with suprasellar tumor: a retrospective analysis of 124 patients

OBJECTIVE

Hydrocephalus is one of the most significant comorbidities of pediatric suprasellar tumors. Up to 37.5-68.0% of patients were diagnosed with hydrocephalus at admission. However, after surgical resection of the tumor, 9.3-51.4% of the hydrocephalus will persist and require a ventriculoperitoneal shunt (VPS) surgery. The purpose of this study was to identify the risk factors associated with postresection shunting in children with suprasellar tumors.

METHODS

We conducted a retrospective analysis of children who underwent surgery for suprasellar tumors at our department from February 2011 to December 2020. We used univariate and multivariate analysis to screen the factors that might be correlated with postoperative shunt placement, taking into account patients' characteristics, tumor histology/size/calcification, the severity of preoperative hydrocephalus, the involvement of ventricles, external ventricular drainage (EVD) placement, postoperative intraventricular hematoma, the extent of resection, and other surgical details.

RESULTS

A total of 124 children who underwent surgery for suprasellar tumors were included in our study. Hydrocephalus was present in 55 patients (44.3%) at admission; 23 patients (18.5%) received VPS implantation after tumor removal. Univariate analysis showed that the involvement of ventricles (p = 0.002), moderate/severe preoperative hydrocephalus (p = 0.001), postoperative intraventricular hematoma (p = 0.005), and EVD implantation (p = 0.001) were significantly associated with postoperative VPS. Multivariate analysis confirmed that only ventricle involvement (p = 0.002; OR = 5.6; 95%CI 1.8-17.2) and intraventricular hematoma (p = 0.01; OR = 10.7; 95%CI 1.8-64.2) were independent risk factors for postresection shunting.

CONCLUSION

Ventricle involvement and intraventricular hematoma can be identified as independent predictors for postoperative shunting in pediatric suprasellar tumors.

Posterior Fossa Tumours in the First Year of Life: A Two-Centre Retrospective Study

Posterior fossa tumours (PFTs) in infants are very rare, and information on these tumours is scarce in the literature. This retrospective study reports their pathological characteristics and describes surgical aspects and treatment outcomes. A two-centre cohort of infants with PFTs treated from 2007 to 2018 was retrospectively reviewed. Patient characteristics, clinical, and treatment data were reviewed. Survival curves for progression-free survival (PFS) and overall survival (OS) were generated. Thirty-three infants were retrieved. There were 11 low grade and 22 high-grade tumours. The most common presenting symptom was intracranial hypertension. Fifteen children out of thirty-three progressed. Five-year PFS was significantly lower in children with high-grade tumours (38.3%) than those with low-grade tumours (69.3%), p = 0.030. High-grade pathology was the only predictor of progression (HR 3.7, 95% CI 1.1–13.31), p = 0.045. Fourteen children with high-grade tumours died, with a 5-year OS of 55.25%. PFTs in children below one year of age still represent a unique challenge. Infants with high-grade tumours display the worst outcomes and the lowest survival, indicating that more effective strategies are needed.