Medical Student UT Southwestern Medical Center Dallas, TX, US
Introduction: Intracranial ependymoma is rare in the adult population. Guidelines for the use of radiation, especially for World Health Organization (WHO) Grade II ependymoma, are not well established. The aim of our study was to investigate the use of stereotactic radiosurgery (SRS) in providing a safe alternative for conventional radiation and minimizing recurrence of intracranial ependymoma.
Methods: A retrospective study was conducted for all cases of adult intracranial ependymoma surgically treated at our institution between January 2000 and July 2024, with median follow-up of 70.1 months (range:0.82-215.1). Patients received gross total resection (GTR), or subtotal resection (STR) with adjuvant external beam radiation; all patients could receive SRS (median dose 18 Gy) to manage recurrence.
Results: Of 39 patients in our analysis; 30.8% were female, with mean age 47.1 (SD 16.8). 22 (56.4%) patients received GTR and 17 (43.6%) received STR, and 31 had WHO grade II, 7 Grade III, and 1 Grade IV tumor at final diagnosis. 20 (51.3%) patients recurred, with 9 receiving SRS (Grade II: 6, III: 3). For all patients, median overall survival (OS) for Grade II and III ependymoma was 43.5 months (range: 4.9-215.1 months) and 36.0 months (range 7.3-150.3 months), with median progression free survival at 30.1 (range: 2.0-153.7) and 22.4 (range: 7.3-130.9), respectively. Overall mortality was 19.4% and 83.3% for Grade II and III tumors, respectively. The median time to recurrence from SRS was 25.5 months (range: 22.5-37.9). 1 patient (11.1%) receiving SRS exhibited radiotoxicity. Although not statistically significant, multivariate Cox regression controlling for tumor grade revealed that compared to conventional adjuvant radiation, receiving SRS improved OS (HR: 0.66,95%:[0.18-2.4],p=0.529) amongst recurrent tumors.
Conclusion : To our knowledge, this is the largest study to highlight the use of SRS as a safe strategy to manage recurrence in adult intracranial ependymoma, with potential to improve overall survival and minimize recurrence.
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