Ostrom QT, Gittleman H, Fulop J et al (2015) CBTRUS statistical report: primary brain and central nervous system tumors diagnosed in the United States in 2008–2012. Neuro Oncol 17:iv1–iv62. https://doi.org/10.1093/neuonc/nov189

Article  PubMed  PubMed Central  Google Scholar 

Louis DN, Perry A, Reifenberger G et al (2016) The 2016 world health organization classification of tumors of the central nervous system: a summary. Acta Neuropathol 131:803–820. https://doi.org/10.1007/s00401-016-1545-1

Article  PubMed  Google Scholar 

Lambrecht M, Eekers DBP, Alapetite C et al (2018) Radiation dose constraints for organs at risk in neuro-oncology; the European particle therapy network consensus. Radiother Oncol 128:26–36. https://doi.org/10.1016/j.radonc.2018.05.001

Article  PubMed  Google Scholar 

Weber DC, Ares C, Villa S et al (2018) Adjuvant postoperative high-dose radiotherapy for atypical and malignant meningioma: a phase-II parallel non-randomized and observation study (EORTC 22042–26042). Radiother Oncol 128(2):260–265. https://doi.org/10.1016/j.radonc.2018.06.018

Article  PubMed  Google Scholar 

Jenkinson MD, Javadpour M, Haylock BJ et al (2015) The ROAM/EORTC-1308 trial: radiation versus observation following surgical resection of atypical meningioma: study protocol for a randomised controlled trial. Trials 16:519. https://doi.org/10.1186/s13063-015-1040-3

Article  CAS  PubMed  PubMed Central  Google Scholar 

Fossati P, Vavassori A, Deantonio L, Ferrara E, Krengli M, Orecchia R (2016) Review of photon and proton radiotherapy for skull base tumours. Rep Pract Oncol Radiother 21(4):336–355. https://doi.org/10.1016/j.rpor.2016.03.007

Article  PubMed  PubMed Central  Google Scholar 

Hardesty DA, Wolf AB, Brachman DG et al (2013) The impact of adjuvant stereotactic radiosurgery on atypical meningioma recurrence following aggressive microsurgical resection. J Neurosurg 119(2):475–481. https://doi.org/10.3171/2012.12.JNS12414

Article  PubMed  Google Scholar 

Champeaux C, Houston D, Dunn L (2017) Atypical meningioma. A study on recurrence and disease-specific survival. Neurochirurgie 63(4):273–281. https://doi.org/10.1016/j.neuchi.2017.03.004

Article  CAS  PubMed  Google Scholar 

Barbaro NM, Gutin PH, Wilson CB, Sheline GE, Boldrey EB, Wara WM (1987) Radiation therapy in the treatment of partially resected meningiomas. Neurosurg 20(4):525–528. https://doi.org/10.1227/00006123-198704000-00003

Article  CAS  Google Scholar 

Chao S, Rogers L (2020) External beam radiation therapy for meningioma. Handb Clin Neurol 170:259–278. https://doi.org/10.1016/B978-0-12-822198-3.00046-X

Article  PubMed  Google Scholar 

Park HJ, Kang HC, Kim IH et al (2013) The role of adjuvant radiotherapy in atypical meningioma. J Neurooncol 115(2):241–247. https://doi.org/10.1007/s11060-013-1219-y

Article  CAS  PubMed  Google Scholar 

Choi CY, Soltys SG, Gibbs IC et al (2010) Cyberknife stereotactic radiosurgery for treatment of atypical (WHO grade II) cranial meningiomas. Neurosurg 67(5):1180–1188. https://doi.org/10.1227/NEU.0b013e3181f2f427

Article  Google Scholar 

Momin AA, Shao J, Soni P et al (2021) Outcomes of salvage radiation for recurrent world health organization grade II meningiomas: a retrospective cohort study. J Neurooncol 152(2):373–382. https://doi.org/10.1007/s11060-021-03711-z

Article  PubMed  Google Scholar 

Shrieve DC, Hazard L, Boucher K, Jensen RL (2004) Dose fractionation in stereotactic radiotherapy for parasellar meningiomas: radiobiological considerations of efficacy and optic nerve tolerance. J Neurosurg 101(Suppl 3):390–395. https://doi.org/10.3171/jns.2004.101.supplement3.0390

Article  PubMed  Google Scholar 

Oya S, Ikawa F, Ichihara N et al (2021) Effect of adjuvant radiotherapy after subtotal resection for WHO grade I meningioma: a propensity score matching analysis of the brain tumor registry of Japan. J Neurooncol 153(2):351–360. https://doi.org/10.1007/s11060-021-03775-x

Article  PubMed  Google Scholar 

Lee G, Lamba N, Niemierko A et al (2021) Adjuvant radiation therapy versus surveillance after surgical resection of atypical meningiomas. Int J Radiat Oncol Biol Phys 109(1):252–266. https://doi.org/10.1016/j.ijrobp.2020.08.015

Article  PubMed  Google Scholar 

Hwang KL, Hwang WL, Bussière MR, Shih HA (2017) The role of radiotherapy in the management of high-grade meningiomas. Chin Clin Oncol 6(Suppl 1):S5. https://doi.org/10.21037/cco.2017.06.09

Article  PubMed  Google Scholar 

Byun HK, Chang WI, Lee JH et al (2022) Adjuvant Radiotherapy Versus Surveillance for Grade 2 intracranial meningiomas: a multi-institutional propensity score-matched study. Front Oncol 12:877244. https://doi.org/10.3389/fonc.2022.877244

Article  CAS  PubMed  PubMed Central  Google Scholar 

Kano H, Takahashi JA, Katsuki T et al (2007) Stereotactic radiosurgery for atypical and anaplastic meningiomas. J Neurooncol 84(1):41–47. https://doi.org/10.1007/s11060-007-9338-y

Article  PubMed  Google Scholar 

Walcott BP, Nahed BV, Brastianos PK, Loeffler JS (2013) Radiation treatment for WHO Grade II and III meningiomas. Front Oncol 3:227. https://doi.org/10.3389/fonc.2013.00227

Article  PubMed  PubMed Central  Google Scholar 

Hemmati SM, Ghadjar P, Grün A et al (2019) Adjuvant radiotherapy improves progression-free survival in intracranial atypical meningioma. Radiat Oncol 14(1):160. https://doi.org/10.1186/s13014-019-1368-z

Article  PubMed  PubMed Central  Google Scholar 

Pirzkall A, Debus J, Haering P et al (2003) Intensity modulated radiotherapy (IMRT) for recurrent, residual, or untreated skull-base meningiomas: preliminary clinical experience. Int J Radiat Oncol Biol Phys 55(2):362–372. https://doi.org/10.1016/s0360-3016(02)03809-9

Article  PubMed  Google Scholar 

Rogers CL, Won M, Vogelbaum MA et al (2020) High-risk meningioma: initial outcomes from NRG Oncology/RTOG 0539. Int J Radiat Oncol Biol Phys 106(4):790–799. https://doi.org/10.1016/j.ijrobp.2019.11.028

Article  PubMed  Google Scholar 

Ferraro DJ, Funk RK, Blackett JW et al (2014) A retrospective analysis of survival and prognostic factors after stereotactic radiosurgery for aggressive meningiomas. Radiat Oncol 9:38. https://doi.org/10.1186/1748-717X-9-38

Article  PubMed  PubMed Central  Google Scholar 

Hanakita S, Koga T, Igaki H et al (2013) Role of gamma knife surgery for intracranial atypical (WHO grade II) meningiomas. J Neurosurg 119(6):1410–1414. https://doi.org/10.3171/2013.8.JNS13343

Article  PubMed  Google Scholar 

Gagliardi F, De Domenico P, Snider S et al (2023) Efficacy of radiotherapy and stereotactic radiosurgery as adjuvant or salvage treatment in atypical and anaplastic (WHO grade II and III) meningiomas: a systematic review and meta-analysis. Neurosurg Rev 46(1):71. https://doi.org/10.1007/s10143-023-01969-7

Article  PubMed  Google Scholar 

Simpson D (1957) The recurrence of intracranial meningiomas after surgical treatment. J Neurol Neurosurg Psychiatry 20(1):22–39. https://doi.org/10.1136/jnnp.20.1.22

Article  CAS  PubMed  PubMed Central  Google Scholar 

Dohm A, McTyre ER, Chan MD et al (2017) Early or late radiotherapy following gross or subtotal resection for atypical meningiomas: clinical outcomes and local control. J Clin Neurosci 46:90–98. https://doi.org/10.1016/j.jocn.2017.08.023

Article  PubMed  PubMed Central  Google Scholar 

Schwartz TH, McDermott MW (2020) The Simpson grade: abandon the scale but preserve the message. J Neurosurg. https://doi.org/10.3171/2020.6.JNS201904

Article  PubMed  PubMed Central  Google Scholar 

Harris TJ, Chao ST, Rogers CL (2018) Meningioma. In: Chang E, Brown P, Lo S, Sahgal A, Suh J (eds) Adult CNS Radiation Oncology. Springer, Cham

Google Sc