Radiotherapy for pediatric central nervous system tumors: a regional cancer centre experience

Embryonal tumors in Canadian children less than 36 months of age: results from the Canadian Pediatric Brain Tumor Consortium (CPBTC)

Embryonal tumors are a heterogeneous group of central nervous system (CNS) tumors whose subgroups have varying incidence and outcome. Despite these differences, they are often grouped as a single entity for study purposes. To date, there are no Canadian multi-institutional studies examining the incidence and outcome of all embryonal subtypes. The current study is an observational study reviewing embryonal tumors in all patients less than 36 months of age diagnosed with a CNS tumor in Canada from 1990 to 2005. Embryonal tumors accounted for 26.9% of all CNS tumors. Medulloblastomas were the highest proportion of the embryonal tumors at 61.5%. Atypical teratoid/rhabdoid tumors (AT/RT) had the second highest proportion of embryonal tumors at 18%. The proportion of primitive neuroectodermal tumors (PNET) was 16%, with 2.6 and 1.9% for congenital medulloepithelioma and ependymoblastoma tumors, respectively. AT/RT and PNET were more common in younger age groups. Medulloblastoma became more prevalent with increasing age, with its highest prevalence in the 25 to 36 month age group. Survival rates for our Canadian population at 18 and 24 months were 0.74 and 0.68 for medulloblastoma, 0.64 and 0.60 for PNET, and 0.36 and 0.29 for AT/RT, respectively. Overall, our data are comparable with published international rates for embryonal tumors. These incidence and outcome figures can guide future research into these rare tumors.

Radiation therapy in paediatric gliomas: our institutional experience

BACKGROUND AND PURPOSE

The aim of our retrospective study was to analyze the clinical outcome of paediatric glioma patients treated with radiation therapy (RT) in our institution.

MATERIAL AND METHODS

We retrieved the case records of all children with gliomas (age < 18 years) who received RT in our department between 2004 and 2007. We analyzed the information regarding patients' demography, clinical details, treatment given, RT details, and survival. The event-free survival (EFS), the period from the date of completion of RT to the date of the event, i.e. death/recurrence, was calculated with respect to age, sex, location of tumour (brainstem vs. non-brainstem), histopathology (low grade vs. high grade), extent of surgical resection, dose and duration of RT, and use of chemotherapy.

RESULTS

A total of 70 children with glioma received RT during the above-mentioned period. The 3-year EFS rate for all patients was 44% and the median EFS period was 18 months. The 3-year EFS in patients who underwent surgical decompression and no surgery was 58% and 25%, respectively (p < 0.05). Patients with brainstem lesions had statistically significantly lower 3-year EFS to non-brainstem gliomas (28% vs. 56%, p < 0.01). Chemotherapy use showed no statistically significant trend towards better survival.

CONCLUSIONS

RT is an effective modality of treatment in paediatric glioma patients in our setup. Early use of RT in incompletely resected low-grade gliomas is worth revisit-ing. Results of chemotherapy in high-grade glioma and brainstem gliomas are encouraging.