Background/Objectives: Neurosurgical resection is the standard treatment for large brain metastases (BMs). Postoperative stereotactic radiotherapy (SRT) is used to reduce local recurrence (LR) but does not always prevent leptomeningeal disease (LMD). This study aims to analyze patterns of tumor recurrence and to identify opportunities for the further improvement of treatment efficacy. Methods: We included 147 patients who underwent resection and SRT for BMs. The distance between the resection cavity target volume and the new tumor growth was calculated. Cox regression analyses were used to assess associations of LMD with various patient characteristics. Results: Median survival after postoperative SRT was 14 months (IQR 6–30) with a 3-year actuarial survival rate of 21%. LR occurred in 20/147 patients (14%). After total resection, LR occurred in 21% of patients after 3 years of follow-up compared to 36% after subtotal resection. Marginal LR occurred in 5/147 patients (3%). LMD was found in 21/147 patients (14%; 3-year actuarial rate, 26%), and it was found more commonly in patients with resected cerebellar metastases (23%; 3-year actuarial rate, 46%) compared to those with cerebral metastases (11%; 3-year actuarial rate 17%) (HR 2.54, 95% CI 1.07–6.04,p= 0.034). Conclusions: This study examined patterns of recurrence after postoperative radiotherapy and its implications for radiation dose, radiation field size, and treatment sequence. Local control was high after total resection. Radiation field size appeared adequate given the low incidence of marginal recurrences. Patients with cerebellar metastases showed an increased risk of LMD, underscoring the need for preventive measures, particularly preoperative SRT.
背景/目的：神经外科切除术是治疗大型脑转移瘤（BMs）的标准方法。术后立体定向放疗（SRT）用于降低局部复发（LR）率，但并非总能预防软脑膜疾病（LMD）。本研究旨在分析肿瘤复发模式，并找出进一步提高治疗效果的潜在机会。方法：我们纳入了147例接受脑转移瘤切除术及术后SRT的患者。计算了切除腔靶区与新发肿瘤生长之间的距离。采用Cox回归分析评估LMD与各种患者特征之间的关联。结果：术后SRT后的中位生存期为14个月（四分位距6-30个月），3年精算生存率为21%。147例患者中有20例（14%）发生LR。全切除术后，3年随访期间LR发生率为21%，而次全切除术后为36%。边缘性LR发生在5/147例患者中（3%）。147例患者中有21例（14%；3年精算率26%）发现LMD，与小脑转移瘤患者（11%；3年精算率17%）相比，切除的小脑转移瘤患者（23%；3年精算率46%）更常见LMD（HR 2.54，95% CI 1.07–6.04，p=0.034）。结论：本研究探讨了术后放疗后的复发模式及其对放疗剂量、照射野大小和治疗顺序的影响。全切除术后局部控制率较高。鉴于边缘性复发率较低，照射野大小似乎足够。小脑转移瘤患者显示出LMD风险增加，这强调了采取预防措施的必要性，尤其是术前SRT。
Patterns of Recurrence After Postoperative Stereotactic Radiotherapy for Brain Metastases
肿瘤(癌症)患者之家