ESTRO 2025 - Abstract Book

S728

Clinical - CNS

ESTRO 2025

Results: Total of 60 patients were included in the study. Median follow-up was 47.5 months. Resection extent significantly influenced PFS ( p =0.0001). Median PFS for gross total resection (GTR) and subtotal resection (STR) was 84 months (95%CI 38-108) and 19 months (95%CI 12-40). Adjuvant RT after STR significantly improved PFS ( p =0.0025). Adjuvant RT showed higher PFS compared to salvage RT ( p =0.007). Multivariate analysis revealed adjuvant RT reduced recurrence risk [HR 0.33 (95%CI 0.15-0.74)]. Male gender [HR 3.00 (95%CI 1.31-6.86)], parasagittal and sellar/parasellar locations [HR 4.68 (95%CI 1.84-11.94) and 2.91 (95%CI 1.07-7.94)], large tumor volume ≥16 cm 3 [HR 1.93 (95%CI 1.05-3.57)], and sheet-like growth [HR 2.40 (95%CI 1.30-4.44)] significantly increased recurrence risk. At the last follow-up, 50 patients (83%) were alive, with mean survival time of 127.78 months (95%CI 114.14-141.42). GTR correlated with longer overall survival (OS) ( p =0.027); adjuvant RT did not significantly impact OS ( p =0.0636). Post-operative complications occurred in 18 patients (30%), with 1.6% experiencing radiation-induced necrosis. Conclusion: Resection extent significantly improved both PFS and OS. Adjuvant RT following STR was associated with improved PFS. Male gender, large tumor size, parasagittal and sellar/parasellar locations, and sheet-like growth were significant risk factors for recurrence. Adjuvant RT demonstrated higher PFS compared to salvage RT. Digital Poster Exploration of the Efficacy and Safety of Anlotinib Combined with Radiotherapy in Treating Newly Diagnosed Pediatric Malignant Brainstem Glioma Yuan-yuan Chen 1,2 , Ying Wang 1,2 1 Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China. 2 State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China Purpose/Objective: Brainstem gliomas (BSGs) are a collective term for gliomas originating from the midbrain, pons, and medulla oblongata. They are among the most complex diseases in central nervous system tumors. Radiotherapy is the standard treatment for brainstem gliomas, especially for diffuse intrinsic tumors. However, its curative effect is not satisfactory and it can only relieve symptoms in a short period of time. Due to the relatively low incidence of BSGs, research on them is very limited. The efficacy of cytotoxic drugs, new targeted drugs, immunotherapy and combination treatment regimens still remains to be evaluated. Anlotinib hydrochloride is a multi-target receptor tyrosine kinase inhibitor. It has inhibitory activity against kinases related to angiogenesis, such as VEGFR1/2/3, FGFR1/2/3, as well as other kinases related to tumors. We conducted an open-label, prospective, single-arm, Phase II clinical trial to observe the efficacy and safety of Anlotinib combined with radiotherapy in the treatment of newly diagnosed malignant brainstem gliomas in children. Material/Methods: The trial is an open-label, prospective, single-arm, Phase II clinical trial for children with newly diagnosed malignant brainstem gliomas. Patients received a total dose of 54 - 60 Gy, with 1.8 - 2 Gy per fraction for 30 fractions, using Intensity-modulated radiotherapy (TOMO/VMAT/IMRT). Anlotinib was administered concurrently and continued after the completion of radiotherapy until disease progression. Anlotinib was started from the first day of radiotherapy. Patients who with 3 to 21 years old and pathologically diagnosed as WHO grade III - IV or clearly diagnosed as high-grade brainstem glioma by imaging are eligible. The primary endpoint is 6-month PFS and the secondary endpoints are PFS, OS, DCR, quality of life and safety. Keywords: meningioma, resection, radiotherapy, recurrence 3683