S393
Clinical - CNS
ESTRO 2026
Adjuvant RT achieved favorable local control and survival with low toxicity in WHO grade 2 meningiomas. A trend toward higher recurrence was noted in the SRS group, possibly due to marginal failures from smaller target volumes. This underscores the importance of adequate clinical target volume (CTV) definition and dural tail coverage when considering radiosurgery for these aggressive tumors. Larger multicenter analyses are warranted to validate these findings and refine RT margin and dose recommendations. References: 1.- Maggio I, Franceschi E, Tosoni A, Nunno V Di, Gatto L, Lodi R, et al. Meningioma: Not always a benign tumor. A review of advances in the treatment of meningiomas. CNS Oncol. 2021 Jun 1;10(2).2.- Chen WC, Perlow HK, Choudhury A, Nguyen MP, Mirchia K, Youngblood MW, et al. Radiotherapy for meningiomas. Vol. 160, Journal of Neuro-Oncology. Springer; 2022. p. 505–15. 3.- Rogers CL, Won M, Vogelbaum MA, et al. High-risk Meningioma: Initial Outcomes From NRG Oncology/RTOG 0539. Int J Radiat Oncol Biol Phys. 2020;106(4):790-799. doi:10.1016/j.ijrobp.2019.11.028. Keywords: WHO grade 2 meningioma, adjuvant radiotherapy Digital Poster 4957 Benign brain tumors' response to radiotherapy: a retrospective study Cristina Pozuelo Aso 1 , Maria Calderó Torra 1 , Angie Yurani Ramos de los Ríos 1 , Rocío del Pilar Pérez Orozco 1 , Fernando Martín Jaramillo Ocharan 1 , Miriam López Mata 1 , German Valtueña Peydró 2 , Victoria Navarro Aznar 1 1 Radiation Oncology, Lozano Blesa Clinical University Hospital, Zaragoza, Spain. 2 Radiation Oncology, Miguel Servet University Hospital, Zaragoza, Spain Purpose/Objective: Benign brain tumors can significantly impact patients’ quality of life, and appropriate treatment is essential to control tumor growth and associated symptoms. Radiotherapy represents one of the key therapeutic options. This study aims to describe the clinical, epidemiological, and treatment characteristics of these tumors, as well as their response to radiotherapy. Material/Methods: A retrospective observational study was conducted, including patients with Vestibular schwannomas, WHO-grade 1 benign Meningiomas, Pituitary adenomas and Craniopharyngiomas. These patients underwent radiotherapy between January 2020 and March 2025. Clinical and epidemiological data (age, sex, ECOG, medical history, histology, diagnosis
Los Lagos, University of Guadalajara, Lagos de Moreno, Mexico
Purpose/Objective: WHO grade 2 meningiomas carry a higher risk of recurrence compared with grade 1 tumors. The primary treatment is maximal safe resection, but adjuvant radiotherapy (RT) plays a crucial role, particularly after subtotal resection (Simpson ≥ III), or inoperable cases where RT is definitive treatment [1, 2].Fractionated RT remains the preferred technique, allowing coverage of microscopic dural and parenchymal extensions while maintaining an acceptable toxicity profile. Stereotactic radiosurgery (SRS) may be considered for small, well-defined residual or recurrent lesions, although the optimal dose, fractionation, and target margins are under investigation [3].This study assessed local control, recurrence patterns, and toxicity in patients with WHO grade 2 meningiomas treated with adjuvant or definitive RT, comparing outcomes between fractionated RT and SRS. Material/Methods: A retrospective observational study included patients with histologically confirmed WHO grade 2 meningiomas treated with adjuvant or definitive RT between 2015 and 2024 at our institution. Demographic, surgical, and dosimetric variables were collected. RT consisted of fractionated RT (54–60 Gy in 27–30 fractions) or SRS, in 15–25 Gy in 1–5 fractions. Local control, recurrence, and survival outcomes were analyzed with descriptive statistics and Chi- square/Fisher’s exact tests. Results: A total of 15 patients were included (66.7 % female; median age = 52 years). The most frequent tumor site was parafalcine (80 %). All patients underwent surgery (Simpson I = 6.7 %, IV = 86.7 %, V = 6.7 %).RT was adjuvant in 93 % and definitive in 7 %. Conventional fractionation was used in 73.3 % (n= 11) and SRS in 26.7 % (n = 4). Median follow-up was 28 months. Local recurrence occurred in 26.7 % overall. Mean progression-free survival was 16.2 months among relapsed cases. Mean overall survival was 93.5 months, with 2- and 5-year OS = 93 % and 86.8 %, respectively. Although not statistically significant, a numerical trend toward higher recurrence was observed in patients treated with single-fraction SRS. Acute CNS toxicity occurred in 60 %, but only 13 % experienced grade ≥ 2 events, all manageable with corticosteroids.
Conclusion:
Made with FlippingBook - Share PDF online