这项研究调查了先线性使用Pembrolizumab和化疗治疗晚期非小细胞肺癌(NSCLC)患者的计算机断层扫描(CT)中的肿瘤负荷动态，提供全身存活(OS)的成像标记。研究包括133名接受先线性Pembrolizumab和铂双联化疗治疗的患者。在治疗期间进行了连续的CT扫描，评估了治疗期间的肿瘤负荷动态，并研究了其与OS的关系。有67名患者对治疗有反应，总体反应率为50%。最佳总体反应时的肿瘤负荷变化范围从-100.0%到+132.1%(中位数为-30%)。更高的反应率与年龄较轻(p<0.001)和程序性细胞死亡-1(PD-L1)表达水平较高(p=0.01)相关。83名患者(62%)的肿瘤负荷低于治疗前。使用8周重要节点分析，与在前8周经历≥0%增加的人相比，肿瘤负荷在前8周低于基线负荷的患者的OS更长(中位OS: 26.8 vs. 7.6个月，危险比(HR): 0.36，p<0.001)。在调整其他临床变量后，负荷始终低于基线的肿瘤携带者生存风险显著降低(HR: 0.72，p=0.03)。只有一名患者(0.8%)出现了假性进展。肿瘤负荷在治疗期间始终低于基线负荷对于接受先线性Pembrolizumab和化疗治疗的晚期NSCLC患者的全身存活预测更长，并可用作该广泛用于组合方案的实用治疗决策标记。肿瘤负荷动态的分析可以提供一个额外的客观指南，用于指导接受先线性Pembrolizumab和化疗治疗的晚期NSCLC患者的治疗决策。

The study investigated tumor burden dynamics on computed tomography (CT) scans in patients with advanced non-small-cell lung cancer (NSCLC) during first-line pembrolizumab plus chemotherapy, to provide imaging markers for overall survival (OS).The study included 133 patients treated with first-line pembrolizumab plus platinum-doublet chemotherapy. Serial CT scans during therapy were assessed for tumor burden dynamics during therapy, which were studied for the association with OS.There were 67 responders, with overall response rate of 50%. The tumor burden change at the best overall response ranged from - 100.0% to + 132.1% (median of - 30%). Higher response rates were associated with younger age (p < 0.001) and higher programmed cell death-1 (PD-L1) expression levels (p = 0.01). Eighty-three patients (62%) showed tumor burden below the baseline burden throughout therapy. Using an 8-week landmark analysis, OS was longer in patients with tumor burden below the baseline burden in the first 8 weeks than in those who experienced ≥ 0% increase (median OS: 26.8 vs. 7.6 months, hazard ratio (HR): 0.36, p < 0.001). Tumor burden remained below their baseline throughout therapy was associated with significantly reduced hazards of death (HR: 0.72, p = 0.03) in the extended Cox models, after adjusting for other clinical variables. Pseudoprogression was noted in only one patient (0.8%).Tumor burden staying below the baseline burden throughout the therapy was predictive of prolonged overall survival in patients with advanced NSCLC treated with first-line pembrolizumab plus chemotherapy, and may be used as a practical marker for therapeutic decisions in this widely used combination regimen.The analysis of tumor burden dynamics on serial CT scans in reference to the baseline burden can provide an additional objective guide for treatment decision making in patients treated with first-line pembrolizumab plus chemotherapy for their advanced NSCLC.• Tumor burden remaining below baseline burden during therapy predicted longer survival during first-line pembrolizumab plus chemotherapy. • Pseudoprogression was noted in 0.8%, demonstrating the rarity of the phenomenon. • Tumor burden dynamics may serve as an objective marker for treatment benefit to guide treatment decisions during first-line pembrolizumab plus chemotherapy.© 2023. The Author(s), under exclusive licence to European Society of Radiology.