Paediatric brain tumours: A review of radiotherapy, state of the art and challenges for the future regarding protontherapy and carbontherapy

BACKGROUND AND PURPOSE

Brain tumours are the most frequent solid tumours in children and the most frequent radiotherapy indications in paediatrics, with frequent late effects: cognitive, osseous, visual, auditory and hormonal. A better protection of healthy tissues by improved beam ballistics, with particle therapy, is expected to decrease significantly late effects without decreasing local control and survival. This article reviews the scientific literature to advocate indications of protontherapy and carbon ion therapy for childhood central nervous system cancer, and estimate the expected therapeutic benefits.

MATERIALS AND METHODS

A systematic review was performed on paediatric brain tumour treatments using Medline (from 1966 to March of 2014). To be included, clinical trials had to meet the following criteria: age of patients 18 years or younger, treated with radiation, and report of survival. Studies were also selected according to the evidence level. A secondary search of cited references found other studies about cognitive functions, quality of life, the comparison of photon and proton dosimetry showing potential dose escalation and/or sparing of organs at risk with protontherapy; and studies on dosimetric and technical issues related to protontherapy.

RESULTS

A total of 7051 primary references published were retrieved, among which 40 clinical studies and 60 papers about quality of life, dose distribution and dosimetry were analysed, as well as the ongoing clinical trials. These papers have been summarized and reported in a specific document made available to the participants of a final 1-day workshop. Tumours of the meningeal envelop and bony cranial structures were excluded from the analysis. Protontherapy allows outstanding ballistics to target the tumour area, while substantially decreasing radiation dose to the normal tissues. There are many indications of protontherapy for paediatric brain tumours in curative intent, either for localized treatment of ependymomas, germ-cell tumours, craniopharyngiomas, low-grade gliomas; or panventricular irradiation of pure non-secreting germinoma; or craniospinal irradiation of medulloblastomas and metastatic pure germinomas. Carbon ion therapy is just emerging and may be studied for highly aggressive and radioresistant tumours, as an initial treatment for diffuse brainstem gliomas, and for relapse of high-grade gliomas.

CONCLUSION

Both protontherapy and carbon ion therapy are promising for paediatric brain tumours. The benefit of decreasing late effects without altering survival has been described for most paediatric brain tumours with protontherapy and is currently assessed in ongoing clinical trials with up-to-date proton devices. Unfortunately, in 2015, only a minority of paediatric patients in France can receive protontherapy due to the lack of equipment.

Social competence in children and young people treated for a brain tumour

PURPOSE

The purposes of this study were to provide a multi-informant assessment of social competence in 8-16-year olds treated for a brain tumour (BT) and then to compare these assessment outcomes to peers.

METHOD

A cross-sectional, mixed (within and between group) design was used to compare a paediatric BT survivor group (n = 33) with an age-matched control group (n = 34) on two multi-informant (self-report, parent, teacher) social competence questionnaires: Social Skills Improvement System (SSIS) and Social Responsiveness Scale (SRS). Demographic factors (age, gender, social economic status (SES), intellectual ability and emotional/behavioural difficulties were investigated as potential non-insult-related risk factors.

RESULTS

Compared to controls, the BT group was reported to have difficulties in social adjustment, interactions and information processing, on both social competence questionnaire measures by parents and teachers, but not self-report. Social competence scores for the BT group were broadly distributed within the normal-severe clinical range, with 40 % of BT survivors scoring in the clinical range for social competence difficulties on the SRS. Lower intellectual ability and emotional/behavioural difficulties accounted for some of the group differences in social competence, but group effects remained once estimated IQ and emotional/behavioural difficulties were controlled for.

CONCLUSIONS

Paediatric BT survivors were reported by parents and teachers to have significant difficulties at all three levels of social competence: adjustment, interaction and information processing. The results highlight the importance of routine assessment in clinic settings for social competence and emotional/behavioural difficulties in BT survivors, to promote early identification and to ensure that survivors are referred for appropriate services and intervention as part of their multi-disciplinary care package.

Approaches to supratentorial brain tumours in children

The differential diagnosis of supratentorial brain tumours in children can be challenging, especially considering the recent changes to the WHO classification of CNS tumours published in 2021. Many new tumour types have been proposed which frequently present in children and young adults and their imaging features are currently being described by the neuroradiology community. The purpose of this article is to provide guidance to residents and fellows new to the field of paediatric neuroradiology on how to evaluate an MRI of a patient with a newly diagnosed supratentorial tumour. Six different approaches are discussed including: 1. Tumour types, briefly discussing the main changes to the recent WHO classification of CNS tumours, 2. Patient age and its influence on incidence rates of specific tumour types, 3. Growth patterns, 4. Tumour location and how defining the correct location helps in narrowing down the differential diagnoses and 5. Imaging features of the tumour on DWI, SWI, FLAIR and post contrast sequences.

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.

The Cerebellar Mutism Syndrome: Risk Assessment, Prevention and Treatment

Cerebellar mutism syndrome (CMS) has received increasing attention over the last decades as a complication of posterior fossa tumour surgery in children. Risk factors, aetiological aspects, and treatment measures of the syndrome have been investigated, yet the incidence of CMS remains unchanged. Overall, we are currently able to identify patients at risk, but we are unable to prevent it from occurring.Once CMS sets in, several symptomatic pharmacological treatments have been suggested, but only in smaller case series and not in randomized controlled trials, and it is not clear whether the treatment or time itself had a helpful effect.Within weeks to months, most patients regain their ability to speak after a phase with mutism or severely reduced speech; however, many patients continue to have speech and language deficits. At this point, anti-cancer treatment with chemotherapy and radiotherapy may be of focus more than the prognosis of CMS; however, many patients continue to have speech and language problems for months and years to come, and they are at high risk of other neurocognitive sequelae as well.Without reliable measures to prevent or treat the syndrome, we may look towards improving the prognosis of speech and neurocognitive functioning in these patients. As speech and language impairment is the cardinal symptom and late effect of CMS, the effect of intense and early-onset speech and language therapy as a standard of care in these patients should be investigated in relation to its effect on regaining speech capacity.

"A tumour registry initiative"

Background

Published literature on epidemiological profile of paediatric brain tumours in India is limited. Aim: To present a retrospective analysis of the histological spectrum of 158 paediatric age group central nervous system tumours operated in a single tertiary care hospital in Coastal South India between January 2015 and December 2021.

Material and methods

Retrospective analysis of the data regarding frequencies of various primary brain tumours among 158 paediatric patients (<18 years of age). The tumours were categorised according to the revised 4th edition of World Health Organization (WHO) classification of tumours of the Central Nervous system.

Results

Paediatric CNS constituted 8.5% of total intracranial tumours (158/1860) operated in the study period. The mean age of the patients was 10.2 years and a definite male predominance was noted (1.54:1) Astrocytomas, glioneuronal tumours, and neuronal tumours constituted the majority (72/158; 45.6%) followed by embryonal tumours (31/158; 19.6%) and craniopharyngiomas(24/158; 15.4%).Of the glial neoplasms majority were pilocytic and other astrocytic tumours(41.6%), followed by mixed neuroglial tumours (19.4%), diffuse high grade astrocytomas (Grade III/IV) (11.1%), diffuse low -grade astrocytomas (Grade II) (9.7%) and ependymomas (13.8%). Our series also included six meningiomas (3.8%), five germ cell tumours (3.16%), four nerve sheath tumours (2.53%), two choroid plexus tumours (1.26%), two pineal parenchymal tumours (1.26%) and one metastasis from a soft tissue sarcoma from the thigh. Supratentorial tumours (58.2%) were more common than posterior fossa (34.6%) and spinal tumours (7.6%) and visual pathway gliomas accounted for 5.6% of all our tumours.

Conclusions

Paediatric central nervous system tumours are more common in boys and in the second decade of life. Astrocytomas are the most common paediatric brain tumours followed by medulloblastomas and craniopharyngiomas. Pediatric tumours affect the supratentorial compartment more often than the infratentorial compartment. The profile of paediatric brain tumours in our series is similar to that reported from other Indian centres as well as most western literature.