2242 - Long-Term Outcomes and Late Effects of Surgery and Radiotherapy in Adult Intracranial Ependymoma Patients
Presenter(s)
O. N. van de Langerijt1,2, F. Ehret3,4, A. Niemierko1, K. S. Oh1, W. Butler5,6, W. T. Curry5,6, B. V. Nahed5,6, D. A. Haas-Kogan1,6, N. J. Patel5,6, A. E. Marciscano1,6, R. Rahman1,6, G. R. J. Janssens2, and H. A. Shih1; 1Department of Radiation Oncology, Mass General Brigham Cancer Institute, Boston, MA, 2Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 3Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Radiation Oncology, Berlin, Germany, 4Department of Radiation Oncology, Mass General Brigham Cancer Institue, Boston, MA, 5Department of Neurosurgery, Mass General Brigham Cancer Institute, Boston, MA, 6Harvard Medical School, Boston, MA
Purpose/Objective(s): To evaluate long-term survival, local control, and radiotherapy-related toxicities in adult patients with intracranial ependymoma.
Materials/Methods: A retrospective study of WHO grade 2-3 adult (=18 years) intracranial ependymoma patients treated with surgery alone or surgery and adjuvant radiotherapy at two high-volume, tertiary referral hospitals between 2000 and 2024 was performed. Univariate Cox regression and Kaplan-Meier analyses were used to estimate progression-free survival (PFS) and overall survival (OS). Late radiotherapy-related toxicity was characterized as occurring at least 90 days after radiotherapy initiation.
Results: Fifty-eight patients met the inclusion criteria. Median age was 39 years (interquartile range [IQR] 25-51), and median follow-up was 4.2 years (IQR 2.0-8.5 years). Overall, 76% were WHO grade 2 tumors, 26% had supratentorial location, gross total resection (GTR) was achieved in 60%, 88% were treated with adjuvant local radiotherapy, and 5% received adjuvant chemotherapy. Adjuvant radiotherapy was more frequently administered to patients with WHO grade 3 tumors (100% versus 84% grade 2), subtotal resection (100% versus 80% GTR), and a higher MIB-1 index (median 5.2 [range 2.1-43.0] versus 2.0 [1.6-3.0]). The median total dose was 54.4 Gy (range 54.0–59.4 Gy), and 47% received proton radiotherapy. Five and 10-year PFS were 80% and 64%, respectively; 5 and 10-year OS were 92% and 85%, respectively. Non-white race was significantly associated with worse PFS. Sex, age, performance status, proliferation index, tumor size, tumor location, extent of resection, and adjuvant radiotherapy were not significantly associated with PFS. Of 11 (19%) recurrences, 18% were detected after five years. Nine (20%) patients developed at least one grade =2 late radiotherapy-related toxicity. Most frequent grade =2 late toxicities were fatigue (7%), ataxia (4%), and memory impairment (4%). The reported grade 3 toxicities included cerebral edema, ataxia, and stroke. One potential secondary glioma (grade 5) occurred after nine years.
Conclusion: This study affirms durable survival rates in adult patients with intracranial ependymoma treated with surgery with or without radiation therapy, but recurrences and late toxicities are not uncommon. Future studies should aim to minimize radiotherapy-related toxicities while maintaining treatment efficacy and ensuring disease control.