Abstract：
177Lu-DOTATATE therapy is an effective treatment for advanced neuroendocrine tumors, despite its dose-limiting hematotoxicity. Herein, the significance of off-target splenic irradiation is unknown. Our study aims to identify predictive markers of peptide receptor radionuclide therapy-induced leukopenia. Methods: We retrospectively analyzed blood counts and imaging data of 88 patients with histologically confirmed, unresectable metastatic neuroendocrine tumors who received 177Lu-DOTATATE treatment at our institution from February 2009 to July 2021. Inclusion criterium was a tumor uptake equivalent to or greater than that in the liver on baseline receptor imaging. We excluded patients with less than 24 mo of follow-up and those patients who received fewer than 4 treatment cycles, additional therapies, or blood transfusions during follow-up. Results: Our study revealed absolute and relative white blood cell counts and relative spleen volume reduction as independent predictors of radiation-induced leukopenia at 24 mo. However, a 30% decline in spleen volume 12 mo after treatment most accurately predicted patients proceeding to leukopenia at 24 mo (receiver operating characteristic area under the curve of 0.91, sensitivity of 0.93, and specificity of 0.90), outperforming all other parameters by far. Conclusion: Automated splenic volume assessments demonstrated superior predictive capabilities for the development of leukopenia in patients undergoing 177Lu-DOTATATE treatment compared with conventional laboratory parameters. The reduction in spleen size proves to be a valuable, routinely available, and quantitative imaging-based biomarker for predicting radiation-induced leukopenia. This suggests potential clinical applications for risk assessment and management.
摘要：
177Lu-DOTATATE疗法是晚期神经内分泌肿瘤的有效治疗方法，尽管其剂量限制性的血液毒性。在这里，非目标脾照射的意义尚不清楚.我们的研究旨在确定肽受体放射性核素治疗引起的白细胞减少症的预测性标志物。方法:回顾性分析88例经组织学证实的患者的血液计数和影像学资料,2009年2月至2021年7月在我们机构接受177Lu-DOTATATE治疗的不可切除的转移性神经内分泌肿瘤。纳入标准是在基线受体成像时肿瘤摄取等于或大于肝脏中的肿瘤摄取。我们排除了随访时间少于24个月的患者和接受少于4个治疗周期的患者，额外的疗法,或随访期间输血。结果：我们的研究显示，绝对和相对白细胞计数以及相对脾脏体积减少是24个月辐射引起的白细胞减少的独立预测因子。然而,治疗后12个月脾脏体积下降30％最准确地预测患者在24个月（受试者操作特征曲线下面积为0.91，敏感性为0.93，特异性为0.90），到目前为止，性能优于所有其他参数。结论：与常规实验室参数相比，自动脾体积评估对接受177Lu-DOTATATE治疗的患者白细胞减少症的发展表现出更好的预测能力。脾脏大小的减小被证明是有价值的，常规可用，和定量成像为基础的生物标志物预测辐射诱导的白细胞减少症。这表明了风险评估和管理的潜在临床应用。
