ESTRO 2025 - Abstract Book

S742

Clinical - CNS

ESTRO 2025

Conclusion: Our analysis suggests that blood cells ratios, particularly the well-known NLR and the new ones SII and SIRI, could have prognostic implications. The addition of inflammatory indicators in the prognostic pathway for GBM could increase the possibility of a personalized approach.

Keywords: brain cancer, glioblastoma, prediction

4197

Digital Poster The efficacy of CyberKnife® stereotactic radiation therapy in re-irradiation of recurrent glioblastoma. Hanna Grzbiela 1 , Malgorzata Stapor-Fudzinska 2 , Elzbieta Nowicka 1 1 III Radiotherapy and Chemotherapy Clinic, Maria Sklodowska-Curie National Research Institute of Oncology, Gliwice, Poland. 2 Radiotherapy Planning Department, Maria Sklodowska-Curie National Research Institute of Oncology, Gliwice, Poland Purpose/Objective: Glioblastoma has a high recurrence rate (up to 90% within two years of the primary treatment). Some patients undergo surgery for recurrence, but often only partial resection is performed. For inoperable and partially resected recurrent tumors stereotactic radiosurgery seem to be an effective and safe treatment option. Material/Methods: 78 patients diagnosed with glioblastoma, aged 24-73 years (median 53), underwent re-irradiation due to tumor recurrence. All patients were treated previously with neurosurgery and radiochemotherapy with the use temozolomide. Primary radiotherapy total dose was 60 Gy. MRI scans were performed every 3 months after the completion of the treatment. Median time to recurrence was 13 months (range 4-37 months). 23 patients underwent partial tumor resection. CyberKnife stereotactic radiation therapy was performed in all patients. Treatment schedule was chosen individually for each patient and depended on tumor volume, location and time