ESTRO 2022 - Abstract Book

S205

Abstract book

ESTRO 2022

Conclusion Eighty percent or more of the clinical oncologists agreed in 27 (64%) cases and of these, 22 (52%) patients were selected for proton therapy. Age and difference in mean dose to the residual brain are important for clinicians’ choice of treatment modality for patients with grade 2 and 3 gliomas. Both parameters are often considered due to the increased risk of development of cognitive decline. Our results will be used to develop a decision support tool to aid the clinicians in future referral processes.

PD-0243 Pediatric diffuse intrinsic pontine glioma treated with radiotherapy: the National multicenter study

H.J. Kim 1 , J.H. Lee 2 , D.H. Lim 3 , Y. Kim 4 , S. Park 5 , S.D. Ahn 6 , I.A. Kim 7 , J.H. Im 8 , J.W. Chung 9 , J. Kim 10 , I.H. Kim 2 , H.I. Yoon 11 , C. Suh 8 1 Gachon University Gil Hospital, Department of Radiation Oncology, Incheon, Korea Republic of; 2 Seoul National University Hospital, Seoul National University, College of Medicine, Department of Radiation Oncology, Seoul, Korea Republic of; 3 Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Radiation Oncology, Seoul, Korea Republic of; 4 Kyung Hee University Medical Center, Kyung Hee University School of Medicine, Department of Radiation Oncology, Seoul, Korea Republic of; 5 School of Medicine, Kyungpook National University, Department of Radiation Oncology, Daegu, Korea Republic of; 6 Asan Medical Center, University of Ulsan College of Medicine, Department of Radiation Oncology, Seoul, Korea Republic of; 7 Seoul National University Bundang Hospital, Department of Radiation Oncology, Seongnam, Korea Republic of; 8 CHA Bundang Medical Center, CHA University School of Medicine, Department of Radiation Oncology, Seongnam, Korea Republic of; 9 Chonnam National University Medical School, Department of Radiation Oncology, Gwangju, Korea Republic of; 10 Proton Therapy Center, National Cancer Center, Department of Radiation Oncology, Goyang, Korea Republic of; 11 Yonsei Cancer Center, Yonsei University college of Medicine, Department of Radiation Oncology, Seoul, Korea Republic of Purpose or Objective This multicenter retrospective study aimed to examine the clinical practice in Korea and investigate the prognostic factors for survival, encompassing clinical and radiologic features and treatments, in newly diagnosed diffuse intrinsic pontine glioma (DIPG) patients treated with radiotherapy. Materials and Methods Patients below 30 years of age and who underwent radiotherapy as an initial treatment for DIPG between 2000 and 2018 were included; patients who did not undergo an MRI at diagnosis and those with pathologically diagnosed grade I glioma were excluded. The medical records of 162 patients were retrospectively collected from 10 participating centers in Korea. The patients’ clinical and radiological variables, molecular and histopathologic data, and treatment response were evaluated to identify the prognosticators for DIPG and estimate survival outcomes. Results The median follow-up period was 10.8 months (interquartile range, 7.5–18.1). The 1- and 2-year overall survival (OS) rates were 53.5 % and 19.0%, respectively, with a median OS of 13.1 months. Long term survival rate ( ≥ 2 years) was 16.7%, and their median OS was 43.6 months. Age (<10 years), poor performance status, treatment before 2010, and post-radiotherapy necrosis were independent prognostic factors related to poor OS in the multivariate analysis. OS improved significantly over time after adjusting for other clinical and treatment factors. In patients with increased post-radiotherapy necrosis, the median OS was 13.3 months for bevacizumab group and 11.4 months for no-bevacizumab group (P = 0.138). The use of chemotherapy, radiotherapy dose, volume, and technique were not significantly related to OS.

Conclusion