Background/Objectives:To report on predictive factors in Linac-based SRT for single and multiple BM.Methods:Consecutive patients receiving either one or three fractions of single-isocenter coplanar VMAT SRT were retrospectively included. The GTV-PTV margin was 1–2 mm. The delivered target dose was estimated by recalculating the original plans on roto-translated CT according to errors recorded by post-treatment CBCT. The Kaplan–Meier method estimated local progression-free survival (LPFS), intracranial progression-free survival (IPFS), and overall survival (OS). Log-rank and Wilcoxon–Mann–Whitney tests evaluated inter-group differences, whereas Cox regression analysis assessed prognostic factors.Results:Fifty females and fifty males, with a median age of 69 years, received 107 SRTs. A total of 213 BM (range, 1–10 per treatment) with a median volume of 0.22 cc were irradiated with a median minimum BED of 59.5 Gy. The median delivered GTV D95 reduction was −0.3%. The median follow-up was 11 months. Nineteen LP events and a 1-year LC rate of 90.1% were observed. The GTV coverage did not correlate with LC, while the GTV volume was a risk factor for LP, with the 1-year rate dropping to 73% for volumes ≥ 0.88 cc. The median LPFS, IPFS, and OS were 6, 5, and 7 months, respectively. Multivariate analysis showed that patients with melanoma histology and those receiving a second or subsequent systemic therapy line had the worst outcomes, whereas patients with adenocarcinoma histology and mutations showed better results.Conclusions:The accuracy and efficacy of the Linac-based SRT approach for BM were confirmed, but the dose distribution alone failed to predict the treatment response, suggesting that other factors must be considered to maximize SRT outcomes.
背景/目的：报告基于直线加速器的立体定向放射治疗（SRT）对单发及多发脑转移瘤（BM）的预测因素。 方法：回顾性纳入连续接受单次或三次单等中心共面容积旋转调强放疗（VMAT）SRT的患者。肿瘤靶区（GTV）至计划靶区（PTV）的外放边界为1–2毫米。通过根据治疗后锥形束CT（CBCT）记录的误差，在旋转平移后的CT上重新计算原始计划，评估实际照射的靶区剂量。采用Kaplan–Meier法评估局部无进展生存期（LPFS）、颅内无进展生存期（IPFS）和总生存期（OS）。使用Log-rank检验和Wilcoxon–Mann–Whitney检验评估组间差异，Cox回归分析评估预后因素。 结果：共纳入50名女性和50名男性患者，中位年龄69岁，接受了107次SRT治疗。共照射213个脑转移瘤（每次治疗1–10个），中位体积为0.22立方厘米，中位最小生物等效剂量（BED）为59.5 Gy。实际照射的GTV D95中位下降幅度为−0.3%。中位随访时间为11个月。观察到19例局部进展事件，1年局部控制率为90.1%。GTV覆盖范围与局部控制无关，而GTV体积是局部进展的风险因素，当体积≥0.88立方厘米时，1年局部控制率降至73%。中位LPFS、IPFS和OS分别为6、5和7个月。多变量分析显示，黑色素瘤组织学类型患者以及接受第二次或后续系统治疗的患者预后最差，而腺癌组织学类型及存在突变的患者预后较好。 结论：基于直线加速器的SRT治疗脑转移瘤的准确性和有效性得到证实，但仅凭剂量分布无法预测治疗反应，提示需综合考虑其他因素以优化SRT疗效。
肿瘤(癌症)患者之家