Bisgaard Anne L H, Brink Carsten, Schytte Tine, Bahij Rana, Weisz Ejlsmark Mathilde, Bernchou Uffe, Bertelsen Anders S, Pfeiffer Per, Mahmood Faisal
Laboratory of Radiation Physics, Department of Oncology, Odense University Hospital, Odense, Denmark.
Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
Front Oncol. 2024 Jul 18;14:1401464. doi: 10.3389/fonc.2024.1401464. eCollection 2024.
Biomarkers for prediction of outcome in patients with pancreatic cancer are wanted in order to personalize the treatment. This study investigated the value of longitudinal diffusion-weighted magnetic resonance imaging (DWI) for prediction of overall survival (OS) in patients with locally advanced pancreatic cancer (LAPC) treated with stereotactic body radiotherapy (SBRT).
The study included 45 patients with LAPC who received 5 fractions of 10 Gy on a 1.5T MRI-Linac. DWI was acquired prior to irradiation at each fraction. The analysis included baseline values and time-trends of the apparent diffusion coefficient (ADC) and DWI parameters obtained using a decomposition method. A multivariable Cox proportional hazards model for OS was made using best-subset selection, using cross-validation based on Bootstrap.
The median OS from the first day of SBRT was 15.5 months (95% CI: 13.2-20.6), and the median potential follow-up time was 19.8 months. The best-performing multivariable model for OS included two decomposition-based DWI parameters: one baseline and one time-trend parameter. The C-Harrell index describing the model's discriminating power was 0.754. High baseline ADC values were associated with reduced OS, whereas no association between the ADC time-trend and OS was observed.
Decomposition-based DWI parameters indicated value in the prediction of OS in LAPC. A DWI time-trend parameter was included in the best-performing model, indicating a potential benefit of acquiring longitudinal DWI during the SBRT course. These findings support both baseline and longitudinal DWI as candidate prognostic biomarkers, which may become tools for personalization of the treatment of patients with LAPC.
为实现胰腺癌患者治疗的个体化，需要能够预测其预后的生物标志物。本研究探讨了纵向扩散加权磁共振成像（DWI）对接受立体定向体部放疗（SBRT）的局部晚期胰腺癌（LAPC）患者总生存期（OS）的预测价值。
本研究纳入了45例LAPC患者，这些患者在1.5T MRI直线加速器上接受了5次每次10Gy的放疗。每次放疗前均采集DWI图像。分析包括表观扩散系数（ADC）的基线值和时间趋势以及使用分解方法获得的DWI参数。使用最佳子集选择法，并基于Bootstrap进行交叉验证，建立了OS的多变量Cox比例风险模型。
从SBRT第一天起的中位OS为15.5个月（95%CI：13.2 - 20.6），中位潜在随访时间为19.8个月。对OS表现最佳的多变量模型包括两个基于分解的DWI参数：一个基线参数和一个时间趋势参数。描述该模型鉴别能力的C-Harrell指数为0.754。高基线ADC值与OS降低相关，而未观察到ADC时间趋势与OS之间的关联。
基于分解的DWI参数在LAPC的OS预测中显示出价值。表现最佳的模型中纳入了一个DWI时间趋势参数，这表明在SBRT疗程中获取纵向DWI可能具有潜在益处。这些发现支持将基线和纵向DWI作为候选预后生物标志物，它们可能成为LAPC患者个体化治疗的工具。
