ESTRO 2024 - Abstract Book

S913

Clinical - CNS

ESTRO 2024

p=0.019) and in patients with age ≤ 60 years (5 -year LC 97% vs 71%, p=0.001; 5-year iPFS 97% vs 64%, p<0.001) (Figure) . On MVA, LC was negatively affected by male sex (HR 0.380, IC95% 0.156-0.926; p=0.033), STR (HR 2.803, IC 95% 1.208-6.506; p=0.016), median Ki-67 > 15% (HR 3.364, IC95% 1.404- 8.063; p=0.007) and KPS ≤ 80 (HR 3.349, IC95% 1.356-8.268; p=0.009); iPFS was negatively affected by male sex (HR 0.256, IC95% 0.102-0.638; p=0.003), STR (HR 4.264, IC95% 1.810- 10.048; p<0.001), KPS ≤ 80 (HR 3.399, IC95% 1.457 -7.932; p=0.005), skull base localization (HR 6.111, IC95% 2.421-15.424; p<0.001) and omission of adjuvant RT after neurosurgical resection (HR 2.766, IC95% 1.197-6.391; p=0.017). Finally, on MVA, OS was favourably affected by KPS > 80 (HR 9.261, IC95% 3.062-28.005; p<0.001) and age ≤ 60 years (HR 6.433, IC95% 1.308 -31.653; p=0.022). Adjuvant RT had no impact on OS, even after stratification for other confounding factors.

Conclusion:

Adjuvant RT in patients with grade 2 meningioma who underwent surgical resection improves LC and PFS, especially in young patients and after GTR. Male gender, elevated Ki- 67, skull base localization and KPS ≤ 80 were also found to negatively affect patients’ outcomes.

Keywords: grade 2 meningioma, adjuvant radiotherapy

References:

1. Lee G, Lamba N, Niemierko A, Kim DW, Chapman PH, Loeffler JS, Curry WT, Martuza RL, Oh KS, Barker FG, et al. Adjuvant Radiation Therapy Versus Surveillance After Surgical Resection of Atypical Meningiomas. Int J Radiat Oncol Biol Phys (2021) 109:252 – 266. doi: 10.1016/j.ijrobp.2020.08.015 2. Weber DC, Ares C, Villa S, Peerdeman SM, Renard L, Baumert BG, Lucas A, Veninga T, Pica A, Jefferies S, et al. Adjuvant postoperative high-dose radiotherapy for atypical and malignant meningioma: A phase-II parallel non randomized and observation study (EORTC 22042-26042). Radiother Oncol (2018) 128:260 – 265. doi: 10.1016/j.radonc.2018.06.018