Smith Eleanor C, Calafiore Rebecca L, Christensen Reid R, Kittel Carol, Munley Michael T, Cramer Christina K, Tatter Stephen B, White Jaclyn J, Chan Michael D, Laxton Adrian W
1Department of Neurosurgery, Wake Forest University School of Medicine, Winston-Salem.
2Wake Forest University School of Medicine, Winston-Salem.
J Neurosurg. 2025 Aug 8:1-6. doi: 10.3171/2025.4.JNS242824.
Stereotactic radiosurgery (SRS) has been used to manage patients with intracranial meningioma with contraindications to resection. Limitations to SRS traditionally include tumors > 3 cm due to the risk of posttreatment toxicity. Hypofractionated SRS (hSRS) has been proposed as an alternative for tumors exceeding volume constraints for single-fraction SRS, although how hypofractionation affects the volume versus toxicity relationship has not been reported. Thus, the authors conducted a single-institution retrospective analysis of the medical records of patients receiving single-fraction SRS or multifraction hSRS for large (> 2 cm) meningiomas to assess the effect of hypofractionation on the likelihood of posttreatment toxicity.
Patients were identified using the Wake Forest University Department of Radiation Oncology prospectively administered Gamma Knife database. Patients were included if they had single-fraction SRS or multifraction hSRS for a diagnosis of meningioma that was > 2 cm. Analysis was limited to tumor volumes between 2.7 and 49.3 cm3, the overlapping range shared by those undergoing hSRS or SRS. Electronic medical records were used to determine patient and tumor characteristics and clinical outcomes.
A total of 121 SRS cases with a median dose of 12 Gy and 51 hSRS cases with a median dose of 20 Gy with tumor volumes between 2.7 and 49.3 cm3 were identified and included in the analysis. The probabilities of freedom from local failure at 1, 3, and 5 years were 87.0%, 79.0%, and 63.6%, respectively, for patients receiving single-fraction SRS and 96.0%, 91.0%, and 91.0%, respectively, for patients receiving multifraction hSRS. The probabilities of overall survival at 1, 3, and 5 years were 97.5%, 79.7%, and 72.6%, respectively, for patients receiving single-fraction SRS and 85.5%, 80.9%, and 76.4%, respectively, for patients receiving multifraction hSRS. Eighteen (14.9%) of 121 patients receiving single-fraction SRS experienced Common Terminology Criteria for Adverse Events (CTCAE) grade ≥ 2 toxicity, and 12 (23.5%) of 51 patients receiving multifraction hSRS experienced CTCAE grade ≥ 2 toxicity.
When controlling for tumor volume, despite higher treatment doses in the hSRS group relative to the SRS group, posttreatment toxicity was not significantly different between the groups, and freedom from local failure was improved in the hSRS group. For patients with larger meningiomas, multifraction hSRS may help to limit the risk of posttreatment edema and toxicity, while maintaining acceptable freedom from local failure.
立体定向放射外科（SRS）已用于治疗有手术切除禁忌证的颅内脑膜瘤患者。传统上，SRS的局限性包括由于治疗后毒性风险，肿瘤直径＞3 cm。对于超过单次分割SRS体积限制的肿瘤，已提出采用低分割SRS（hSRS）作为替代方案，不过低分割如何影响体积与毒性的关系尚未见报道。因此，作者对接受单次分割SRS或多分割hSRS治疗大型（＞2 cm）脑膜瘤患者的病历进行了单机构回顾性分析，以评估低分割对治疗后毒性可能性的影响。
利用维克森林大学放射肿瘤学系前瞻性管理的伽玛刀数据库识别患者。如果患者因诊断为脑膜瘤且肿瘤直径＞2 cm而接受单次分割SRS或多分割hSRS，则纳入研究。分析仅限于肿瘤体积在2.7至49.3 cm³之间，这是接受hSRS或SRS患者的重叠范围。使用电子病历确定患者和肿瘤特征以及临床结局。
共识别出121例接受单次分割SRS的病例，中位剂量为12 Gy，51例接受多分割hSRS的病例，中位剂量为20 Gy，肿瘤体积在2.7至49.3 cm³之间，并纳入分析。接受单次分割SRS的患者在1年、3年和5年时无局部复发的概率分别为87.0%、79.0%和63.6%，接受多分割hSRS的患者分别为96.0%、91.0%和91.0%。接受单次分割SRS的患者在1年、3年和5年时的总生存率分别为97.5%、79.7%和72.6%，接受多分割hSRS的患者分别为85.5%、80.9%和76.4%。121例接受单次分割SRS的患者中有18例（14.9%）发生了不良事件通用术语标准（CTCAE）≥2级毒性反应，51例接受多分割hSRS的患者中有12例（23.5%）发生了CTCAE≥2级毒性反应。
在控制肿瘤体积时，尽管hSRS组的治疗剂量相对于SRS组更高，但两组之间的治疗后毒性无显著差异，且hSRS组的无局部复发情况有所改善。对于较大脑膜瘤患者，多分割hSRS可能有助于限制治疗后水肿和毒性的风险，同时维持可接受的无局部复发率。
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