ESTRO 2025 - Abstract Book

S687

Clinical - CNS

ESTRO 2025

Treatment was well tolerated, with grade 2 toxicity occurring in 13.6% of patients and grade 3 toxicity in 4.55%. No grade 4 toxicities were reported.

Conclusion: Reirradiation (Re-RT) was shown to be a safe and feasible treatment option with low toxicity. Our findings indicate that patients with later relapses after initial treatment tend to have longer survival following reirradiation. Additionally, higher doses (compared to medium doses) may have a positive impact on patient survival.

Keywords: Reirradiation, gliomas, survival

1995

Mini-Oral Adult newly malignant brainstem glioma treated with anlotinib plus radiotherapy: a multicenter, phase II study Yuan-yuan Chen 1 , Pei-jing Li 2 1 Department of Radiation Oncology, Sun Yat-sen University Cancer Centre, Guangzhou, China. 2 Department of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou, China Purpose/Objective: Due to the challenging location, adult malignant brainstem glioma can not undergo aggressive surgery and is associated with a quite poor prognosis. Effective therapy regimens for this disease have not been developed. This study assessed the efficacy and safety of anlotinib, a multitarget tyrosine kinase inhibitor, combined with radiotherapy in treating this group of patients. Material/Methods: This is an ongoing phase II, multicenter, single-arm trial investigating the safety, tolerability, and activity of anlotinib combined with radiotherapy in malignant brainstem glioma. Eligible participants include adults (18-70 years old) with newly diagnosed malignant (WHO Ⅲ - Ⅳ ) brainstem glioma based on histology or radiology who are radiotherapy (RT), chemotherapy, immunotherapy, or biotherapy naïve. Patients with Karnofsky score ＜ 40 and a life expectancy ＜ 3 months are excluded. All participants received 54-60 Gy radiotherapy (RT ， 1.8-2.0 Gy per fraction, five days per week). Anlotinib (10mg, orally, daily, d1-14/3 weeks) concurrently administered with radiotherapy, then consolidatedly used until disease progression or occurrence of intolerable adverse events. The primary objective includes disease control rate (DCR) and 6-month progression-free survival rate (6m-PFS). The secondary objective includes overall survival (OS), and toxicity profile (NCT04668508). Results: As of November 18, 2024, 22 participants have enrolled, 21 patients have completed radiotherapy. Sixteen patients who with a follow-up of 3 months or longer were included in the analysis for this report. The median age is 38 (range 18-68) years old. The median follow-up is 24.6 (range 3.1-39.3) months. Nine patients were pathologically diagnosed and nine patients were radiologically diagnosed with high-grade glioma. The DCR is 100% (Stable disease, SD: 21/21) at the end of radiotherapy and is 100% three months after radiotherapy (Partial response, PR: 3/21; SD: 18/21). The median PFS is 10.7 months, 95%CI 5.9-15.5, and the 6m-PFS and 1 year-PFS rates are 90.0% and 42.0%. The median OS is 19.9 months, 95%CI 13.6-26.2, the 6m-OS and 1 year-OS rates are 100%and 67.4%. No death occurred during the treatment. No ≥ grade 3 adverse events were observed up to the last follow-up (November 18, 2024) of this study.