Typical Pediatric Brain Tumors Occurring in Adults-Differences in Management and Outcome

5-Aminolevulinic acid (5-ALA) in paediatric brain tumour surgery-a systematic review and exploration of fluorophore alternatives

PURPOSE

Paediatric brain tumours represent the most common solid malignancies in children, with extent of resection being a critical prognostic factor. Fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) is well-established for adult high-grade gliomas, but its efficacy and safety in paediatric populations remain unclear. This systematic review evaluates the utility of 5-ALA fluorescence-guided surgery in paediatric brain tumours and explores alternative fluorophores.

METHODS

A systematic review was conducted according to PRISMA guidelines, analysing studies from MEDLINE and EMBASE published up to October 2024. Data on patient demographics, tumour fluorescence patterns, surgical outcomes, and adverse effects were extracted. Statistical analyses assessed fluorescence differences across tumour types and administration parameters.

RESULTS

Twenty-three studies, including 281 paediatric patients (mean age, 10 years), were analysed. The most common tumours included pilocytic astrocytomas (n = 45), medulloblastomas (n = 45), glioblastomas (n = 35), and ependymomas (n = 27). Strong fluorescence was observed more frequently in high-grade gliomas compared to low-grade gliomas (p < 0.00001), non-glioma tumours (p < 0.00001), and high-grade non-glioma tumours (p = 0.000485). Adverse effects were mostly transient; rare complications included transaminitis and dermatologic reactions.

CONCLUSION

5-ALA fluorescence-guided surgery shows promise in the resection of high-grade gliomas in paediatric patients, improving intraoperative visualisation. However, limited fluorescence in low-grade and non-glioma tumours underscores the need for tumour-specific approaches. Emerging alternatives, such as fluorescein sodium and tozuleristide, offer potential advantages. Future research should focus on optimising 5-ALA dosing, refining timing protocols, and conducting robust prospective trials to establish efficacy and safety in paediatric populations.

Pediatric neurosurgery training during residency in Switzerland and the need for dedicated subspecialization training

INTRODUCTION

Pediatric Neurosurgery as a subspeciality started to emerge during the late 1950s, with only a few dedicated pediatric neurosurgeons in the Western world. Over the last few decades, the awareness that children require subspecialized care by dedicated pediatric neurosurgeons and an interdisciplinary team has been growing worldwide, leading to an increase in pediatric neurosurgeons. Several studies have shown that subspecialized care for pediatric patients improves outcomes and is cost-effective. This survey aims to assess the current setting of pediatric neurosurgery and training of neurosurgical residents in pediatric neurosurgery in Switzerland.

METHODS

We conducted an online survey by sending e-mail invitations in 2021 to all neurosurgical residents in Switzerland. The survey included questions regarding the participants' demographics, current workplace structures, the care of specific pediatric neurosurgical pathologies, and participants' opinions of the Swiss training program for pediatric neurosurgery and possible improvement. We defined at the beginning of the survey that a pediatric neurosurgeon is a board-certified neurosurgeon with at least one year of dedicated pediatric neurosurgical fellowship training abroad.

RESULTS

We received a total of 25 responses from residents, of which 20 (80%) were male. Twenty-two participants (88%) worked in one of seven major hospitals in Switzerland at the time of the survey, and four (16%) were interested in pursuing a fellowship in pediatric neurosurgery. Seven (35%) and five residents (25%) feel comfortable taking care on the ward of a craniosynostosis and hydrocephalus patient younger than 6 months, respectively. Twelve residents (60%) feel comfortable taking care of a pediatric brain tumor patient. The majority (n = 22, 88%) of all residents agree that a fellowship-trained pediatric neurosurgeon should treat children, while two (8%) residents state that any neurosurgeon with an interest in pediatric neurosurgery should be able to treat children. All residents (n = 25, 100%) agree that pediatric neurosurgery training and care in Switzerland needs to be improved.

CONCLUSION

Pediatric neurosurgery training in Switzerland is rather heterogeneous and not very well structured, with varying frequencies of children-specific neurosurgical pathologies. Most residents agreed that a subspecialized pediatric neurosurgeon should oversee the care of children in neurosurgery, while all agree that pediatric neurosurgical training and care should be improved in Switzerland.

Development of a high-throughput screening platform to identify new therapeutic agents for Medulloblastoma Group 3

Pediatric brain tumors (PBTs) represent about 25 % of all pediatric cancers and are the most common solid tumors in children and adolescents. Medulloblastoma (MB) is the most frequently occurring malignant PBT, accounting for almost 10 % of all pediatric cancer deaths. MB Group 3 (MB G3) accounts for 25-30 % of all MB cases and has the worst outcome, particularly when associated with MYC amplification. However, no targeted treatments for this group have been developed so far. Here we describe a unique high throughput screening (HTS) platform specifically designed to identify new therapies for MB G3. The platform incorporates optimized and validated 2D and 3D efficacy and toxicity models, that account for tumor heterogenicity, limited efficacy and unacceptable toxicity from the very early stage of drug discovery. The platform has been validated by conducting a pilot HTS campaign with a 1280 lead-like compound library. Results showed 8 active compounds, targeting MB reported targets and several are currently approved or in clinical trials for pediatric patients with PBTs, including MB. Moreover, hits were combined to avoid tumor resistance, identifying 3 synergistic pairs, one of which is currently under clinical study for recurrent MB and other PBTs.

Pediatric-Like Brain Tumors in Adults

Pediatric brain tumors are different to those found in adults in pathological type, anatomical site, molecular signature, and probable tumor drivers. Although these tumors usually occur in childhood, they also rarely present in adult patients, either as a de novo diagnosis or as a delayed recurrence of a pediatric tumor in the setting of a patient that has transitioned into adult services.Due to the rarity of pediatric-like tumors in adults, the literature on these tumor types in adults is often limited to small case series, and treatment decisions are often based on the management plans taken from pediatric studies. However, the biology of these tumors is often different from the same tumors found in children. Likewise, adult patients are often unable to tolerate the side effects of the aggressive treatments used in children-for which there is little or no evidence of efficacy in adults. In this chapter, we review the literature and summarize the clinical, pathological, molecular profile, and response to treatment for the following pediatric tumor types-medulloblastoma, ependymoma, craniopharyngioma, pilocytic astrocytoma, subependymal giant cell astrocytoma, germ cell tumors, choroid plexus tumors, midline glioma, and pleomorphic xanthoastrocytoma-with emphasis on the differences to the adult population.

Management and Long-term Outcomes of Adults With Medulloblastoma: A Single-Center Experience

BACKGROUND AND OBJECTIVES

Medulloblastomas are embryonal tumors predominantly affecting children. Recognition of molecularly defined subgroups has advanced management. Factors influencing the management and prognosis of adult patients with medulloblastoma remains poorly understood.

METHODS

We examined the management, prognostic factors, and, when possible, molecular subgroup differences (subset) in adult patients (aged 18 years or older) with medulloblastoma from our center (specialty Neuro-Oncology clinic within a large academic practice) diagnosed between 1992 and 2020. Molecular subtyping corresponding to the 2021 WHO Classification was performed. Kaplan-Meier estimates (with log-rank test) were performed for univariate survival analysis with Cox regression used for multivariate analyses.

RESULTS

We included 76 adult patients with medulloblastoma (62% male), with a median age of 32 years at diagnosis (range: 18-66) and median follow-up of 7.7 years (range: 0.6-27). A subset of 58 patients had molecular subgroup characterization-37 SHH-activated, 12 non-WNT/non-SHH, and 9 WNT-activated. Approximately 67% underwent gross total resection, 75% received chemotherapy at diagnosis, and 97% received craniospinal irradiation with boost. The median overall survival (OS) for the whole cohort was 14.8 years. The 2-, 5-, and 10-year OS rates were 93% (95% CI 88-99), 86% (78-94), and 64% (53-78), respectively. Survival was longer for younger patients (aged 30 years or older: 9.9 years; younger than 30 years: estimated >15.4 years; log-rank p < 0.001). There was no survival difference by molecular subgroup or extent of resection. Only age at diagnosis remained significant in multivariate survival analyses.

DISCUSSION

We report one of the largest retrospective cohorts in adult patients with medulloblastoma with molecular subtyping. Survival and molecular subgroup frequencies were similar to prior reports. Survival was better for adult patients younger than 30 years at diagnosis and was not significantly different by molecular subgroup or management characteristics (extent of resection, RT characteristics, or chemotherapy timing or regimen).

Contemporary Biological Insights and Clinical Management of Craniopharyngioma

Craniopharyngiomas (CPs) are clinically aggressive tumors because of their invasive behavior and recalcitrant tendency to recur after therapy. There are 2 types based on their distinct histology and molecular features: the papillary craniopharyngioma (PCP), which is associated with BRAF-V600E mutations and the adamantinomatous craniopharyngioma (ACP), characterized by mutations in CTNNB1 (encoding β-catenin). Patients with craniopharyngioma show symptoms linked to the location of the tumor close to the optic pathways, hypothalamus, and pituitary gland, such as increased intracranial pressure, endocrine deficiencies, and visual defects. Treatment is not specific and mostly noncurative, and frequently includes surgery, which may achieve gross total or partial resection, followed by radiotherapy. In cystic tumors, frequent drainage is often required and intracystic instillation of drugs has been used to help manage cyst refilling. More recently targeted therapies have been used, particularly in PCP, but also now in ACP and clinical trials are underway or in development. Although patient survival is high, the consequences of the tumor and its treatment can lead to severe comorbidities resulting in poor quality of life, in particular for those patients who bear tumors with hypothalamic involvement. Accordingly, in these patients at risk for the development of a hypothalamic syndrome, hypothalamus-sparing treatment strategies such as limited resection followed by irradiation are recommended. In this review, we provide an update on various aspects of CP, with emphasis on recent advances in the understanding of tumor pathogenesis, clinical consequences, management, and therapies.

Neurosurgical Treatment and Outcome of Pediatric Skull Base Lesions: A Case Series and Review of the Literature

INTRODUCTION

Pediatric skull base lesions occur rarely and are of various etiologies. Traditionally, open craniotomy has been the treatment of choice; however, nowadays, endoscopic approaches are increasingly applied. In this retrospective case series, we describe our experience in treating pediatric skull base lesions and provide a systematic overview of the literature on the treatment and outcome of pediatric skull base lesions.

METHODS

We conducted a retrospective data collection of all pediatric patients (<18 years) treated for a skull base lesion at the Division of Pediatric Neurosurgery, University Children's Hospital Basel, Switzerland, between 2015 and 2021. Descriptive statistics and a systematic review of the available literature were additionally conducted.

RESULTS

We included 17 patients with a mean age of 8.92 (±5.76) years and nine males (52.9%). The most common entity was sellar pathologies (n = 8 47.1%), with craniopharyngioma being the most common pathology (n = 4, 23.5%). Endoscopic approaches, either endonasal transsphenoidal or transventricular, were used in nine (52.9%) cases. Six patients (35.3%) suffered from transient postoperative complications, while in none of the patients these were permanent. Of the nine (52.9%) patients with preoperative deficits, two (11.8%) showed complete recovery and one (5.9%) partial recovery after surgery. After screening 363 articles, we included 16 studies with a total of 807 patients for the systematic review. The most common pathology reported in the literature confirmed our finding of craniopharyngioma (n = 142, 18.0%). The mean PFS amongst all the studies included was 37.73 (95% CI [36.2, 39.2]) months, and the overall weighted complication rate was 40% (95% CI [0.28 to 0.53] with a permanent complication rate of 15% (95% CI [0.08 to 0.27]. Only one study reported an overall survival of their cohort of 68% at five years.

CONCLUSION

This study highlights the rarity and heterogeneity of skull base lesions in the pediatric population. While these pathologies are often benign, achieving GTR is challenging due to the deep localization of the lesions and eloquent adjacent structures, leading to high complication rates. Therefore, skull base lesions in children require an experienced multidisciplinary team to provide optimal care.

Long-term outcome after management of pilocytic astrocytoma in the posterior fossa in a pediatric population

Background and purpose

To assess the impact of posterior fossa pilocytic astrocytoma (PA) removal in pediatric patients, with special focus on postoperative neurological outcome after repeated surgery for tumor remnants.

Methods

Our institutional database was screened for patients with PA treated between 2000 and 2019. Patients ≤ 18 years of age with complete clinical records, preoperative contrast enhanced magnetic resonance imaging (MRI) and postoperative follow-up time of ≥ 6 months were suitable for study inclusion. Functional outcome was quantified with the modified Ranking Scale (mRS) score and assessed at admission, at discharge and at every follow-up investigation. Predictors of hydrocephalus, cranial nerve deficits and tumor recurrence were evaluated.

Results

A total of 57 pediatric patients with a mean age of 7.7 ± 4.8 years were included in the analysis. 27 (47.3%) children suffered from hydrocephalus at diagnosis, out of which 19 (33.3%) required a subsequent VP-Shunt. 22 (39.3%) patients had a partial resection, of which 9 (40.9%) went through second-look surgery. 2 patients with initially radiological confirmation of complete resection, had a tumor recurrence at FU and needed second-look surgery. Among the children requiring second-look surgery, 7 (63.6%) had a complete resection. Favorable outcome (mRS≤2) after initial and second-look surgery was observed in 52 patients (91.2%). Univariate analysis identified tumor location in the floor of the 4th ventricle (p = 0.030), and repeated surgery for tumor remnant removal (p = 0.043) as predictors for post-operative cranial nerve deficits. Multivariate analysis confirmed this independent association. The incidence of tumor recurrence occurred more often in patients with previous partial resection (p = 0.009) as well as in lesions located in the cerebellar peduncles (p = 0.043). Partial resection remained an independent predictor after multivariate logistic regression analysis (p = 0.045).

Conclusions

Incomplete resection of posterior fossa PA is a risk factor for tumor recurrence and repeated surgery to remove tumor remnants increases the risk of new postoperative deficits. Thus, the risk of iatrogenic deterioration due to second look surgery should be implemented in the primary pre- and intraoperative decision-making.

Transitional Care in Pediatric Brain Tumor Patients: A Systematic Literature Review

BACKGROUND

Due to advances in the treatment of pediatric brain tumors (PBT), an increasing number of patients are experiencing the transition from the pediatric to the adult health care system. This requires efficient transitional models.

METHODS

We systematically reviewed the literature regarding PBT concerning different transitional models and aspects of the transitional period. For this purpose, PubMed, Medline, and Embase databases were searched systematically through January 2022.

RESULTS

We reviewed a total of 304 studies, of which 15 were ultimately included. We identified five transition models described within the literature, while the most frequently mentioned ones were the "adult caregiver model" (45.5%), "joint caregiver model" (45.5%), "continued caregiver model" (27.3%), and the "specialized clinic model" (27.3%). During the transition, the most frequent challenges mentioned by the patients were the lack of knowledge about the disease by the adult health care professionals (62.5%) and the difficulty of establishing a new relationship with the new physician, environment, or hospital (37.5%).

CONCLUSIONS

An efficient transitional model is mandatory for patients with PBT. Continuity in the treatment and care of the patient and their family is essential. For this purpose, in patients with PBT, the "continued caregiver model", and for NF1 and TSC patients, the "specialized clinic model" seems optimal to offer continuity of care. If such models are unavailable, efficient communication with patients, families, and specialists in a multidisciplinary network is even more critical.