Systematic Review and Meta-Analysis of Adjuvant Radiation Dose for Pediatric Patients (≤22 years) with Nonmetastatic Intracranial Ependymomas

Melanie L Rose; Rhea Sachdeva; Yakout Mezgueldi; Renata W Yen; Laila Andaloussi Serraj; Kelly L Corbett; Torunn I Yock

doi:10.1016/j.ijrobp.2024.07.2335

Systematic Review and Meta-Analysis of Adjuvant Radiation Dose for Pediatric Patients (≤22 years) with Nonmetastatic Intracranial Ependymomas

Int J Radiat Oncol Biol Phys. 2024 Aug 13:S0360-3016(24)03206-1. doi: 10.1016/j.ijrobp.2024.07.2335. Online ahead of print.

Authors

Melanie L Rose¹, Rhea Sachdeva², Yakout Mezgueldi², Renata W Yen³, Laila Andaloussi Serraj², Kelly L Corbett⁴, Torunn I Yock⁵

Affiliations

¹ Dartmouth Cancer Center, Dartmouth-Hitchcock, Lebanon, New Hampshire; The Dartmouth Institute, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire. Electronic address: melanie.l.rose@hitchcock.org.
² The Dartmouth Institute, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire.
³ The Dartmouth Institute, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire; Department of Biomedical Data Science, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire.
⁴ The Dartmouth Institute, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire; Department of Pediatrics, Dartmouth Health Children's, Lebanon, New Hampshire.
⁵ Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.

PMID: 39147207
DOI: 10.1016/j.ijrobp.2024.07.2335

Abstract

Purpose: Ependymomas are the third most common brain tumors in children. Standard of care is surgery followed by adjuvant radiation therapy. Controversy in the literature still exists over optimal radiation therapy dose. We completed a systematic review and meta-analysis to determine the optimal dose for local control (LC), event-free survival (EFS), and overall survival (OS) in pediatric patients.

Methods and materials: We searched MEDLINE (PubMed), Cochrane Database of Systematic Reviews, and Web of Science through January 2024. We included cohort studies that compared adjuvant radiation therapy of ≤54 Gy with >54 Gy in pediatric patients (≤22 years) with nonmetastatic intracranial ependymomas. We assessed study quality using the Newcastle-Ottawa Quality Assessment Scale of Cohort Studies. We pooled studies using a random effects meta-analysis for hazard ratios (HR), 95% confidence intervals (CI), and assessed statistical heterogeneity via I². When HRs were unavailable, we transformed risks using established methods. We narratively summarized qualitative outcomes.

Results: Seven studies met our inclusion criteria, covering a combined 1321 patients. Studies included a range of doses from 45 to 66.6 Gy. Compared with >54 Gy, we found no difference in LC for those receiving ≤54 Gy (HR, 0.83; 95% CI, 0.56-1.24; I², 49.1%), in EFS (HR, 1.02; 95% CI, 0.95-1.09; I², 0.00%), and OS (HR, 0.99; 95% CI, 0.82-1.20; I², 37.5%). Two studies reported on subtotal resection by radiation therapy dose, neither study reporting statistical differences in LC, EFS, or OS, although the number of patients was small (n ≤ 30). Five studies reported on late effects, with brainstem radionecrosis, radiation-induced vasculopathy, and secondary tumors being the most frequent. Overall study quality was high, although lower scores were consistently seen in comparability of cohorts. To our knowledge, no studies reported on molecular subgroups.

Conclusions: We found no difference in LC, EFS, or OS for those treated with ≤54 Gy compared with >54 Gy. There were insufficient data to complete a subgroup meta-analysis on radiation therapy dosing based on extent of resection or molecular subgroups.