ESTRO 2022 - Abstract Book

S630

Abstract book

ESTRO 2022

Mini-Oral: 18: CNS

MO-0719 Adult Intracranial Ependymal Tumors: Results of TROD Neurooncology Group 07-009 Study

S. Aytac Arslan 1 , Y. Guney 2 , P. Erpolat 3 , S. Kamer 4 , E. Erci ş 5 , Y. Tezcan 6 , Z. Akgun 7 , B. Atalar 8 , D. Karacetin 9 , G. Guler 10

1 Ankara Memorial Hospital, Radiation Oncology, Ankara, Turkey; 2 Yüksek İ htisas University Medical School, Radiation Oncology, Ankara, Turkey; 3 Gazi University Medical School , Radiation Oncology , Ankara, Turkey; 4 Ege University Medical School , Radiation Oncology , İ zmir, Turkey; 5 Sivas Cumhuriyet University Medical School , Radiation Oncology , Sivas, Turkey; 6 Yildirim Beyazit University Medical School , Radiation Oncology , Ankara, Turkey; 7 Sisli Memorial Hospital, Radiation Oncology , İ stanbul, Turkey; 8 Acıbadem University Medical School , Radiation Oncology , İ stanbul, Turkey; 9 Basaksehir City Hospital, Radiation Oncology , İ stanbul, Turkey; 10 Gaziosmanpasa University Medical School , Radiation Oncology , Tokat, Turkey Purpose or Objective Intracranial ependymomas in adults are rare, the literature generally includes children’s series with relatively small number of patients. Current standard of care consists of maximal safe resection with or without radiotherapy (RT) and chemotherapy (CT) depending on the age of the patient, location of the tumor, and extent of resection. Development of new surgical techniques enabled the increased the chance of resection which is strongly correlated with oncological outcomes. RT, on the other hand, can be applied more accurately and precisely today so that re-irradiation can be possible. The aim of this retrospective study is to evaluate the treatment results of adult patients with intracranial ependymoma who underwent RT or were followed up in radiation oncology clinics in our country. Materials and Methods The data of 43 adult patients diagnosed with ependymoma between 13.02.1998 and 21.05.2021 in 9 different centers in our country were evaluated retrospectively. The primary endpoints were Overall survival (OS) and Progression-free survival (PFS). SPSS version 22 was used for analysis. The categorical demographic characteristics of the patients were analyzed with Chi-square and Fisher's exact test, Spearman’s rank correlation test was used for univariate correlation analysis, Kaplan Meier was used for univariate survey analyzes, Cox regression test was used for multivariate analyzes and the significance limit was 0.05. Results The patients' and treatment characteristics are summarized in Table 1. Median follow-up time was 49.3 months (3-282). At the time of last follow up 14 patients (32.6%) died, and 15 (34.6%) patients relapsed. Ten (66.7%) of the recurrences were at the tumor site. Relapsed thirteen patients had salvage treatments; 3 (23.1%) received chemotherapy, 1 (7.7%) underwent surgery + chemotherapy, 2 (15.4%) had surgery + reRT, 7 (53.8%) received reRT. A total of 9 patients re-irradiated; 8 had local RT (SRT and IMRT) and 1 had CSI. During the follow-up period median OS was 62 months (range 2-282) and median PFS was 37 months (range 2-282). The 1 and 5-year OS and PFS were 92.6% and 68.3% and 89% and 60.3% respectively. Age, gender, localization, type of resection, and grade didnot significantly affect survival. The relationship between OS and salvage treatment is significant, with significantly higher OS in patients receiving 2 nd line RT (p0.004; HR 0.36; 95% CI 0.050- 2.679). PFS was significantly affected by localization (supra vs infra p0.010; HR 0.21; %95 CI 0.059-0.775), type of surgery (GTR vs others p0.024; HR 0.29; %95 CI 0.095-0.900) and grade (p0.004; HR 4.3; %95 CI 1.148-12.898).