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Published on: February 6, 2019
Proton radiotherapy for pediatric central nervous system ependymoma: clinical outcomes for 70 patients
Shannon M Macdonald1, Roshan Sethi, Beverly Lavally
1This paper was presented at the International Symposium on Pediatric Neuro-Oncology on June 24, 2012, in Toronto, Canada.Corresponding Author: Shannon MacDonald, MD, Massachusetts General Hospital, Department of Radiation Oncology, Yawkey 112, 30 Fruit Street, Boston, MA 02114. smacdonald@partners.org.
Insights
Proton radiotherapy (PRT) offers favorable outcomes for intracranial ependymoma, especially in young children. Subtotal resection (STR) is linked to worse survival, highlighting PRT
Area of Science:
- Pediatric Oncology
- Radiation Oncology
- Neuro-oncology
Background:
- Ependymoma treatment involves maximal surgical resection and radiotherapy.
- Minimizing radiation exposure is crucial for young children.
- Proton radiotherapy (PRT) spares healthy tissues but has limited outcome data.
Purpose of the Study:
- To report clinical outcomes of intracranial ependymoma treated with PRT.
- To evaluate the efficacy and safety of PRT in pediatric ependymoma patients.
Main Methods:
- Seventy patients with localized ependymoma received involved-field PRT.
- Data collected on patient demographics, tumor characteristics, and treatment details.
- Follow-up included assessment of local control, survival, and neurocognitive/adaptive skills.
Main Results:
- Three-year local control, progression-free survival, and overall survival were 83%, 76%, and 95%, respectively.
- Subtotal resection (STR) was associated with significantly worse progression-free and overall survival compared to gross total resection (GTR).
- Neurocognitive and adaptive skills remained stable, with minimal adverse effects like growth hormone deficiency or hypothyroidism.
Conclusions:
- PRT outcomes for pediatric intracranial ependymoma compare favorably with existing literature.
- STR is a significant negative prognostic factor for survival.
- PRT is an ideal radiation modality for ependymoma due to patient age and critical structure proximity.
Background:
Ependymoma is treated with maximal surgical resection and localized radiotherapy. Minimizing unnecessary exposure to radiation is of paramount importance for young children. Proton radiotherapy (PRT) spares healthy tissues outside the target region, but reports of clinical outcomes are scarce. We report outcomes for 70 patients treated with PRT for intracranial ependymoma.
Methods:
Seventy patients with localized ependymoma treated with involved-field PRT at the Massachusetts General Hospital between October 2000 and February 2011 were included.
Results:
Median age at diagnosis was 38 months (range, 3 mo-20 y). Nineteen (27%) patients had supratentorial ependymoma and 51(73%) had infratentorial ependymoma. Forty-six (66%) had gross total resection (GTR), and 24 (34%) had subtotal resection (STR). At a median follow-up of 46 months, 3-year local control, progression-free survival, and overall survival were 83%, 76%, and 95%, respectively. STR was significantly associated with worse progression-free survival (54% vs 88%, P = .001) and overall survival (90% vs 97% for GTR, P = .001). In a subset of patients (n = 14), mean intelligence was 108.5 at baseline and 111.3 after mean 2.05 years of follow-up. In a larger group of patients (n = 28), overall adaptive skills were 100.1 at baseline and 100.8 after 2.21 years of follow-up. Few patients developed evidence of growth hormone deficiency, hypothyroidism, or hearing loss.
Conclusion:
Outcomes for children treated with PRT compare favorably with the literature. STR correlated with inferior outcome. The young age at diagnosis and the proximity of critical structures in patients with ependymoma make PRT an ideal radiation modality.
