Ependymoma: a Retrospective Analysis of 25 Cases

We evaluated the patterns of failure, survival rate, prognostic factors and treatment related complication in postoperative radiation treatment of patients with ependymoma.

We retrospectively analyzed 25 patients with histologically confirmed ependymoma treated between Jun. 1990 and Jun. 2001 with postoperative radiotherapy at Asan Medical Center. The study group comprised of 16 men and 9 women, with a median age of 23 years; including 6 supratentorial, 15 infratentorial and 4 spinal cord lesions. The extents of resection were ranked as either: gross total, near total, subtotal, partial resection or biopsy, with these types of surgical resection being performed in 13, 3, 6, 1 and 2 patients, respectively. Twelve of the patients had low grade ependymoma, and the other 13 a high grade tumor. The postoperative irradiation was administered using 4 MV or 6 MV photons, up to median dose of 55.0 Gy (range, 45.0~59.4 Gy), with the radiation field encompassing the preoperative tumor volume plus a 2 cm margin. Only 8 of the patients received either pre- or postoperative chemotherapy. The median follow-up period of survivors was 43 months.

Ten of the 25 patients (40%) developed a recurrence, and 5 died. Of the 10 recurred patients, 6 showed an in-field recurrence, and one developed both an in-field and an out of field recurrence. The remaining 3 patients showed an out of field recurrence, including one case with a leptomeningeal recurrence. The 5-year overall survival, and progression-free, survival rates were 74.0 and 56.1%, respectively. The histological grades were statistically significant prognostic factors of the overall and progression-free survival rates. There were no significant treatment related complications, with the exception of one case of panhypopituitarism, which occurred 30 months after completion of the radiotherapy.

The main pattern of recurrence was due to local failure. In order to improve the local control, and to reduce complications, advanced radiation treatment techniques, such as 3 dimensional radiotherapy, may be needed.