为了比较全身弥散加权成像（WB-DWI）和18F－氟脱氧葡萄糖（[18F]FDG）PET/MRI在小儿霍奇金淋巴瘤和非霍奇金淋巴瘤的肿瘤治疗反应评估中的应用，在一项回顾性、非随机的单中心研究中，我们回顾了45名儿童和年轻成人（27名男性；平均年龄13岁±5；年龄范围1-21岁）的霍奇金淋巴瘤（n = 20）和非霍奇金淋巴瘤（n = 25）的序列同步WB-DWI和[18F]FDG PET/MRI扫描。我们测量了最小肿瘤表观扩散系数（ADCmin）和最大标准摄取值（SUVmax）的六个靶病灶，并根据Lugano标准和WB-DWI的修正标准评估了治疗反应。我们使用Gwet的一致性系数（AC）评估了WB-DWI和[18F]FDG PET/MRI的治疗反应分类之间的一致性。诱导化疗后，95%（20/20）的霍奇金淋巴瘤患者和72%（18/25）的非霍奇金淋巴瘤患者在肿瘤代谢和质子扩散方面呈一致反应。我们发现，在霍奇金淋巴瘤患者中，WB-DWI和[18F]FDG PET/MRI的治疗反应评估之间存在高度一致性（Gwet's AC = 0.94；95% CI: 0.82, 1.00），而非霍奇金淋巴瘤患者的一致性较低（Gwet's AC = 0.66；95% CI: 0.43, 0.90）。治疗完成后，WB-DWI和[18F]FDG PET/MRI的治疗反应评估之间存在卓越一致性（Gwet's AC = 0.97；95% CI: 0.91, 1）。霍奇金淋巴瘤的治疗反应可以用[18F]FDG PET或WB-DWI来评估，而非霍奇金淋巴瘤患者可能受益于联合方法。霍奇金淋巴瘤和非霍奇金淋巴瘤在扩散加权MRI和PET/MRI上对诱导化疗的肿瘤反应表现出不同的模式。扩散加权成像被提议作为一种无电离辐射评估肿瘤反应的替代成像技术。诱导治疗后，全身WB-DWI和PET/MRI在霍奇金淋巴瘤患者中显示出较高的一致性，而对于非霍奇金淋巴瘤患者，则一致性较低。综合而言，在疗程结束时，全身WB-DWI和PET/MRI对所有淋巴瘤类型的肿瘤治疗反应评估显示出优秀的一致性。© 2023年作者（专有许可），欧洲放射学学会。

To compare tumor therapy response assessments with whole-body diffusion-weighted imaging (WB-DWI) and 18F-fluorodeoxyglucose ([18F]FDG) PET/MRI in pediatric patients with Hodgkin lymphoma and non-Hodgkin lymphoma.In a retrospective, non-randomized single-center study, we reviewed serial simultaneous WB-DWI and [18F]FDG PET/MRI scans of 45 children and young adults (27 males; mean age, 13 years ± 5 [standard deviation]; age range, 1-21 years) with Hodgkin lymphoma (n = 20) and non-Hodgkin lymphoma (n = 25) between February 2018 and October 2022. We measured minimum tumor apparent diffusion coefficient (ADCmin) and maximum standardized uptake value (SUVmax) of up to six target lesions and assessed therapy response according to Lugano criteria and modified criteria for WB-DWI. We evaluated the agreement between WB-DWI- and [18F]FDG PET/MRI-based response classifications with Gwet's agreement coefficient (AC).After induction chemotherapy, 95% (19 of 20) of patients with Hodgkin lymphoma and 72% (18 of 25) of patients with non-Hodgkin lymphoma showed concordant response in tumor metabolism and proton diffusion. We found a high agreement between treatment response assessments on WB-DWI and [18F]FDG PET/MRI (Gwet's AC = 0.94; 95% confidence interval [CI]: 0.82, 1.00) in patients with Hodgkin lymphoma, and a lower agreement for patients with non-Hodgkin lymphoma (Gwet's AC = 0.66; 95% CI: 0.43, 0.90). After completion of therapy, there was an excellent agreement between WB-DWI and [18F]FDG PET/MRI response assessments (Gwet's AC = 0.97; 95% CI: 0.91, 1).Therapy response of Hodgkin lymphoma can be evaluated with either [18F]FDG PET or WB-DWI, whereas patients with non-Hodgkin lymphoma may benefit from a combined approach.Hodgkin lymphoma and non-Hodgkin lymphoma exhibit different patterns of tumor response to induction chemotherapy on diffusion-weighted MRI and PET/MRI.• Diffusion-weighted imaging has been proposed as an alternative imaging to assess tumor response without ionizing radiation. • After induction therapy, whole-body diffusion-weighted imaging and PET/MRI revealed a higher agreement in patients with Hodgkin lymphoma than in those with non-Hodgkin lymphoma. • At the end of therapy, whole-body diffusion-weighted imaging and PET/MRI revealed an excellent agreement for overall tumor therapy responses for all lymphoma types.© 2023. The Author(s), under exclusive licence to European Society of Radiology.