Purpose

The outcomes of five fraction stereotactic radiotherapy (hfSRT) following brain metastasectomy were evaluated and compared with published series.

Methods

30 Gy in 5 fractions HfSRT prescribed to the surgical cavity was reduced to 25 Gy if the volume of ‘brain−GTV’ receiving 20 Gy exceeded 20 cm³. Endpoints were local recurrence, nodular leptomeningeal recurrence, new brain metastases and radionecrosis. The literature was searched for reports of clinical and dosimetric outcomes following postoperative hfSRT in 3–5 fractions.

Results

39 patients with 40 surgical cavities were analyzed. Cavity local control rate at 1 year was 33/40 (82.5%). 3 local failures followed 30 Gy/5 fractions and 4 with 25 Gy/5 fractions. The incidence of leptomeningeal disease (LMD) was 7/40 (17.5%). No grade 3–4 toxicities, particularly no radionecrosis, were reported. The incidence of distant brain metastases was 15/40 (37.5%). The median overall survival was 15 months. Across 13 published series, the weighted mean local control was 83.1% (adjusted for sample size), the mean incidence of LMD was 14.9% (7–34%) and the mean rate of radionecrosis was 10.3% (0–20.6%).

Conclusion

Postoperative hfSRT can be delivered with 25–30 Gy in 5 fractions with efficacy in excess of 82% and no significant toxicity when the dose to ‘brain−GTV’ does not exceed 20 cm³.

中文翻译：

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脑转移瘤切除术后五次立体定向放射治疗：单机构经验和文献回顾

目的

评估脑转移瘤切除术后五次立体定向放射治疗 (hfSRT) 的结果，并与已发表的系列进行比较。

方法

如果接受 20 Gy 的“脑-GTV”体积超过 20 cm ³，则 30 Gy 5 次 终点是局部复发、结节性软脑膜复发、新的脑转移瘤和放射性坏死。在文献中检索了 3-5 次 hfSRT 术后临床和剂量学结果的报告。

结果

分析了 40 个手术腔的 39 名患者。1 年蛀牙局部控制率为 33/40 (82.5%)。30 Gy/5 次分割后 3 次局部失败，25 Gy/5 次分割后 4 次。软脑膜疾病 (LMD) 的发病率为 7/40 (17.5%)。没有报告 3-4 级毒性，特别是没有放射性坏死。远处脑转移的发生率为 15/40 (37.5%)。中位总生存期为 15 个月。在 13 个已发表的系列中，加权平均局部控制率为 83.1%（根据样本量调整），LMD 的平均发生率为 14.9%（7-34%），放射性坏死的平均率为 10.3%（0-20.6%）。

结论

术后 hfSRT 可分 5 次以 25-30 Gy 进行，当“脑-GTV”的剂量不超过 20 cm ³时，疗效超过 82% 且无明显毒性。