Peritumoral cerebral edema is reported to be a side effect that can occur after stereotactic radiosurgery. We aimed to determine whether intratumoral necrosis (ITN) is a risk factor for peritumoral edema (PTE) when gamma knife radiosurgery (GKRS) is performed in patients with meningioma. In addition, we propose the concept of pseudoprogression: a temporary volume expansion that can occur after GKRS in the natural course of meningioma with ITN. This retrospective study included 127 patients who underwent GKRS for convexity meningioma between January 2019 and December 2020. Risk factors for PTE and ITN were investigated using logistic regression analysis. Analysis of variance was used to determine whether changes in tumor volume were statistically significant. After GKRS, ITN was observed in 34 (26.8%) patients, and PTE was observed in 10 (7.9%) patients. When postoperative ITN occurred after GKRS, the incidence of postoperative PTE was 18.970-fold (p = 0.009) greater. When a 70% dose volume ≥ 1 cc was used, the possibility of ITN was 5.892-fold (p < 0.001) higher. On average, meningiomas with ITN increased in volume by 128.5% at 6 months after GKRS and then decreased to 94.6% at 12 months. When performing GKRS in meningioma, a 70% dose volume ≥ 1 cc is a risk factor for ITN. At 6 months after GKRS, meningiomas with ITN may experience a transient volume expansion and PTE, which are characteristics of pseudoprogression. These characteristics typically improve at 12 months following GKRS.

据报道，瘤周脑水肿是立体定向放射外科手术后可能发生的副作用。我们旨在确定在脑膜瘤患者进行伽马刀放射外科手术 (GKRS) 时，瘤内坏死 (ITN) 是否是瘤周水肿 (PTE) 的危险因素。此外，我们提出了假性进展的概念：GKRS 后脑膜瘤伴 ITN 的自然病程中可能发生的暂时性体积扩张。这项回顾性研究包括 2019 年 1 月至 2020 年 12 月期间接受 GKRS 治疗凸面脑膜瘤的 127 名患者。使用逻辑回归分析调查 PTE 和 ITN 的危险因素。方差分析用于确定肿瘤体积的变化是否具有统计学意义。GKRS 后，34 例 (26.8%) 患者出现 ITN，10 例 (7. 9%) 患者。当 GKRS 后发生术后 ITN 时，术后 PTE 的发生率高出 18.970 倍 (p = 0.009)。当使用 70% 剂量体积 ≥ 1 cc 时，ITN 的可能性高 5.892 倍 (p < 0.001)。平均而言，ITN 脑膜瘤在 GKRS 后 6 个月时体积增加 128.5%，然后在 12 个月时下降至 94.6%。在脑膜瘤中进行 GKRS 时，70% 剂量体积 ≥ 1 cc 是 ITN 的危险因素。在 GKRS 后 6 个月，伴 ITN 的脑膜瘤可能会出现短暂的体积扩张和 PTE，这是假性进展的特征。这些特征通常在 GKRS 后 12 个月时得到改善。高 892 倍 (p < 0.001)。平均而言，ITN 脑膜瘤在 GKRS 后 6 个月时体积增加 128.5%，然后在 12 个月时下降至 94.6%。在脑膜瘤中进行 GKRS 时，70% 剂量体积 ≥ 1 cc 是 ITN 的危险因素。在 GKRS 后 6 个月，伴 ITN 的脑膜瘤可能会出现短暂的体积扩张和 PTE，这是假性进展的特征。这些特征通常在 GKRS 后 12 个月时得到改善。高 892 倍 (p < 0.001)。平均而言，ITN 脑膜瘤在 GKRS 后 6 个月时体积增加 128.5%，然后在 12 个月时下降至 94.6%。在脑膜瘤中进行 GKRS 时，70% 剂量体积 ≥ 1 cc 是 ITN 的危险因素。在 GKRS 后 6 个月，伴 ITN 的脑膜瘤可能会出现短暂的体积扩张和 PTE，这是假性进展的特征。这些特征通常在 GKRS 后 12 个月时得到改善。