Kretzschmar Lena, Gabrys Hubert, Joye Anja, Kraft Johannes, Guckenberger Matthias, Andratschke Nicolaus
Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland.
Department of Radiation Oncology, Kantonsspital Aarau, Aarau, Switzerland.
Clin Exp Metastasis. 2025 Feb 10;42(2):16. doi: 10.1007/s10585-025-10334-5.
Postoperative radiotherapy improves local control (LC) after resection of brain metastases. In comparison to whole brain radiotherapy (WBRT) stereotactic radiosurgery (SRS) to resection cavity significantly reduces cognitive side effects. However, two phase-III trials have reported suboptimal LC with SRS, leading to increased interest in hypofractionated stereotactic radiotherapy (SRT) as an alternative to improve outcomes. This single-centre study, based on a prospective quality assurance protocol, included 161 patients with 185 resected brain metastases treated with either SRS or SRT between February 2018 and June 2023. Patients were assigned to treatment based on cavity size, with SRS typically used for cavities < 10 cc and SRT for larger volumes. Primary and secondary endpoints were LC and radiation necrosis (RN), respectively. Data analysis was conducted retrospectively. Median cavity size was 13.3 cc, with 20% of cavities receiving SRS and 80% SRT. 12-month LC was 92.6% (95-CI: 88.2 - 97.3%), 12-month RN incidence was 9% (95-CI: 3-14%), with RN limited to CTCAE v5 ≤ 2. In cavities < 10 cc, no significant difference in LC was found between SRS and SRT. For cavities > 10 cc, PTV volume was the only significant predictor of LC, while fractionation and dose did not significantly impact outcomes. SRS and SRT both offer excellent LC for resection cavities < 10 cc with low rates of RN, suggesting SRS as the preferred treatment in this collective, in consideration of patient comfort and resource allocation. In larger cavities, PTV volume significantly influences LC. Dose escalation might be beneficial in improving outcomes in these cases.
术后放疗可改善脑转移瘤切除术后的局部控制（LC）。与全脑放疗（WBRT）相比，立体定向放射外科（SRS）治疗切除腔可显著降低认知副作用。然而，两项III期试验报告了SRS的局部控制效果欠佳，这使得人们对大分割立体定向放疗（SRT）作为改善治疗效果的替代方案的兴趣增加。这项单中心研究基于前瞻性质量保证方案，纳入了2018年2月至2023年6月期间接受SRS或SRT治疗的161例患者的185个切除的脑转移瘤。根据腔大小分配患者接受治疗，SRS通常用于腔体积<10 cc的情况，SRT用于较大体积的情况。主要和次要终点分别为局部控制和放射性坏死（RN）。数据分析采用回顾性分析。中位腔体积为13.3 cc，20%的腔接受SRS治疗，80%接受SRT治疗。12个月时的局部控制率为92.6%（95%置信区间：88.2 - 97.3%），12个月时放射性坏死发生率为9%（95%置信区间：3 - 14%），放射性坏死仅限于美国国立癌症研究所不良事件通用术语标准第5版（CTCAE v5）≤2级。在腔体积<10 cc的情况下，SRS和SRT之间的局部控制无显著差异。对于腔体积>10 cc的情况，计划靶体积（PTV）是局部控制的唯一显著预测因素，而分割方式和剂量对结果无显著影响。SRS和SRT对腔体积<10 cc的切除腔均提供了良好的局部控制且放射性坏死发生率低，考虑到患者舒适度和资源分配，提示SRS是这类患者的首选治疗方法。在较大的腔中，PTV体积显著影响局部控制。在这些情况下剂量增加可能有利于改善治疗效果。
