Erratum to: Re-irradiation of recurrent anaplastic ependymoma using radiosurgery or fractionated stereotactic radiotherapy

Purpose Recurrent ependymomas were retreated with stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT). The efficacy, toxicities, and differences between SRS and FSRT were analyzed. Methods Eight patients with recurrent ependymomas fulfilling the criteria described below were evaluated. Inclusion criteria were: (1) the patient had previously undergone surgery and conventional radiotherapy as first-line treatment; (2) targets were located in or adjacent to the eloquent area or were deep-seated; and (3) the previously irradiated volume overlapped the target lesion. Results FSRT was delivered to 18 lesions, SRS to 20 lesions. A median follow-up period was 23 months. The local control rate was 76 % at 3 years. No significant differences in local control were observed due to tumor size or fractionation schedule. Lesions receiving >25 Gy/5 fr or 21 Gy/3 fr did not recur within 1 year, whereas no dose–response relationship was observed in those treated with SRS. No grade ≥2 toxicity was observed. Conclusion Our treatment protocol provided an acceptable LC rate and minimal toxicities. Because local recurrence of tumors may result in patient death, a minimum dose of 21 Gy/3 fr or 25 Gy/5 fr or higher may be most suitable for treatment of these cases.