We conducted a phase II trial of conformal radiation therapy (CRT) for localized childhood ependymoma to determine whether the irradiated volume could be reduced to decrease CNS-related side effects without diminishing the rate of disease control.

Between July 1997 and January 2003, 88 pediatric patients (median age, 2.85 +/- 4.5 years) received CRT in which doses (59.4 Gy to 73 patients or 54.0 Gy after gross-total resection to 15 patients younger than 18 months) were administered to the gross tumor volume and a margin of 10 mm. Patients were categorized according to extent of resection (underwent gross total resection, n = 74; near-total resection, n = 6; subtotal resection, n = 8), prior chemotherapy (n = 16), tumor grade (anaplastic, n = 35), and tumor location (infratentorial, n = 68). An age-appropriate neurocognitive battery was administered before and serially after CRT.

The median length of follow-up was 38.2 months (+/- 16.4 months); the 3-year progression-free survival estimate was 74.7% +/- 5.7%. Local failure occurred in eight patients, distant failure in eight patients, and both in four patients. The cumulative incidence of local failure as a component of failure at 3 years was 14.8% +/- 4.0%. Mean scores on all neurocognitive outcomes were stable and within normal limits, with more than half the cohort tested at or beyond 24 months.

Limited-volume irradiation achieves high rates of disease control in pediatric patients with ependymoma and results in stable neurocognitive outcomes.