ESTRO 2022 - Abstract Book

S978

Abstract book

ESTRO 2022

Conclusion This real-world, selective approach and propensity score matching analysis showed that CNI+SRT led to an improvement in OS compared to CNI, corroborating prior findings that local therapy with SRT or surgery improved OS in patients treated with CNI for MBM, regardless of the timepoint of local therapy.

PO-1152 Prognostic impact of lymphopenia during temozolomide chemoradiation in patients with glioblastoma

W.C. You 1

1 Taichung Veterans General Hospital, Department of Radiation Oncology, Taichung, Taiwan

Purpose or Objective Postoperative chemoradiation with temozolomide is the standard treatment for glioblastoma. The severe treatment-related lymphopenia has been studied to be associated with a poor prognosis in elderly glioblastoma patients. This study aims to evaluate the impact of peri-chemoradiation lymphopenia on survival. Materials and Methods We retrospectively enrolled 139 glioblastoma patients who underwent surgery and were postoperatively treated with temozolomide chemoradiation between January 2012 and June 2018. Adjuvant monthly temozolomide was given for all patients. The severity of lymphopenia is according to Common Terminology Criteria for Adverse Events (CTCAE) 4.0. Results Among 139 patients, the median progression-free time (PFS) and overall survival time (OST) are 7.2 and 24.0 months. Grade III and IV lymphopenia were found in 19 and 2 patients during chemoradiation. The patients who experienced at least once grade III or above lymphopenia (n=23) had significantly worse median OST when compared with those who did not (95% CI: 8.4-13.4 vs. 16.2-26.0 months, p <0.001). Seventy-seven patients received bevacizumab monotherapy after progression. The OST is significantly better in the patients treated with bevacizumab monotherapy, with a median of 28.7months compared to 10.5 months in the non-bevacizumab-treated patients (95% CI: 24.1-33.3 vs. 9.0-12.0 months, p <0.001). The Cox multivariate analysis indicated age, bevacizumab, and grade III or above lymphopenia are significantly independent factors for OST ( p =0.025, p <0.001, and p= 0.001, respectively) Conclusion Peri-chemoradiation lymphopenia is a prognostic predictor for glioblastoma. These findings provided evidence that immunosuppression induced by chemoradiation is associated with poor clinical outcomes

PO-1153 Toxicity of hypofractionated radiotherapy and TMZ in elderly patients with glioblastoma

S. Payano 1 , J. Zapatero 2 , D. de las Peñas 3 , E. Amaya 2 , P. Samper 2

1 Hospital Universitario Rey Juan carlos, Radiation Oncology, Madrid, Spain; 2 Hospital Universitario Rey Juan Carlos, Radiation Oncology, Madrid, Spain; 3 Hospital Universitario Rey Juan Carlos, Radiation oncology, Madrid, Spain Purpose or Objective The purpose of this study was to evaluate the acute toxicity and the effectiveness of hypofractionated radiation therapy with concurrent temozolomide in terms of disease control in primary glioblastoma patients with poor prognostic factors. Materials and Methods we reviewed the treatment toxicities and overall survival of patients 65 years or older who were treated with chemoradiotherapy Between November 2013 and september 2021. Twelve elderly, and/or disabled patients received