The recurrence rate after partial surgical resection (STR) of atypitcal meningioma (AM) can be as high as 36%-83%, and even after gross total resection (GTR) there is still a 9%-32% recurrence rate. Radiation therapy is an important treatment for recurrent AM, but it is still unclear whether the best radiation therapy for AM is external beam radiation therapy (EBRT) or stereotactic radiosurgery (SRS), as well as the timing of radiation therapy and the risk factors for recurrence after radiation therapy. Sam Q. Sun et al. of the University of Washington School of Medicine conducted a relevant clinical study, the results of which were published online in the November 2015 issue of Neurosurgery. Radiotherapy administered to treat residual tumors within 1 year after surgery was defined as adjuvant radiotherapy, and radiotherapy administered to treat tumor progression recurrence on imaging was defined as salvage radiotherapy. Of the 863 meningioma patients at this medical center, 50 were AM patients treated with radiotherapy after craniotomy; the mean dose was 18 Gy for SRS and 54 Gy for EBRT. patients were closely followed up and Cox regression analysis and survival analysis were used to screen for predictors of tumor progression after radiotherapy. Of the 50 patients, 29 were women and 21 were men with a mean age of 59 years; 44% had parafalcine meningiomas and 42% had skull base meningiomas. The mean follow-up time was 86 months. Adjuvant radiotherapy was administered to 32 patients and salvage radiotherapy to 18 patients. 21 patients (42%) were treated with SRS and 7 patients showed tumor progression; 29 patients (58%) were treated with EBRT and 13 patients showed tumor progression (Table 1). Tumor volume, SRS and EBRT, adjuvant and salvage radiotherapy were not associated with tumor progression; spontaneous necrosis within the tumor (HR=82.3, p=0.0002), embolic necrosis (HR=15.6, p=0.03) and tumor cell invasion into brain tissue (HR=3.8, p=0.008) all increased the risk of tumor recurrence (Table 2). tumors after SRS The 2- and 5-year local control rates were 91% and 88%, respectively, while the 2- and 5-year local control rates of tumors after EBRT were 71% and 69%, respectively, with no significant differences. Pathological examination suggested that local control rates of tumors at 2 and 5 years were 76% and 92% for those with spontaneous necrosis in the tumor, 100% and 36% for those with embolic necrosis in the tumor, and 73% and 100% for those without tissue necrosis in the tumor (p<0.001).