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Updated: Jul 6, 2026

Role of Diffusion MRI Tractography in Endoscopic Endonasal Skull Base Surgery
Published on: July 5, 2021
A retrospective study of surgery and reirradiation for recurrent ependymoma
Thomas E Merchant1, Frederick A Boop, Larry E Kun
1Department of Radiological Sciences, Division of Radiation Oncology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA. thomas.merchant@stjude.org
Purpose:
To report disease control for patients with recurrent ependymoma (EP) treated with surgery and a second course of radiation therapy (RT(2)).
Patients And Methods:
Thirty-eight pediatric patients (median age, 2.7 years) with initially localized EP at the time of definitive RT underwent a second course of RT after local (n = 21), metastatic (n = 13), or combined (n = 4) failure. Reirradiation included radiosurgery (n = 6), focal fractionated reirradiation (n = 13), or craniospinal irradiation (CSI; n = 19).
Results:
Initial time to failure was 16 months, and median age at second treatment was 4.8 years. Radiosurgery resulted in significant brainstem toxicity and one death (median dose, 18 Gy). Progression-free survival ratio was greater than unity for 4 of 6 patients; there was one long-term survivor. Three of 13 patients treated using focal fractionated reirradiation (median combined dose, 111.6 Gy) experienced metastasis. The CSI was administered to 12 patients with metastatic failure, 3 patients with local failure, and 4 patients with combined failure. The 4-year event-free survival rate was 53% +/- 20% for 12 patients with metastatic failure treated with CSI. Failure after CSI was observed in 1 of 3 patients with a history of local failure and 3 of 4 patients with a history of combined failure.
Conclusion:
Patients with locally recurrent EP experience durable local tumor control, but remain at risk of metastasis. Patients with metastatic EP failure may receive salvage therapy that includes a component of CSI. Durability of disease control and long-term effects from this approach require further follow-up.
