国际小儿肿瘤学会肾肿瘤研究组 (SIOP-RTSG) 不鼓励在诊断时采用侵入性操作来确定小儿肾肿瘤的组织学。因此，在新辅助化疗开始时，肾母细胞瘤（WT）的组织学亚型是未知的。 MR-DWI 通过表观扩散系数 (ADC) 显示出作为非侵入性生物标志物的潜在价值。本研究旨在描述儿童肾肿瘤的 MR 特征和 ADC 值，以区分亚型。前瞻性地纳入了 2021 年 5 月至 2023 年期间接受 SIOP-RTSG 2016-UMBRELLA 方案中接受手术的肾肿瘤儿童。 ，基于新辅助 MR 的患者特异性切割指南是 3D 打印的，允许成像和组织病理学之间的相关性。将整个肿瘤体积和 ADC 值与 Mann-Whitney U 检验进行统计比较。通过混合模型分析对显微镜载玻片水平的直接相关性进行分析。纳入了54名患者（58％男性，中位年龄3.0岁（范围0-17.7岁））的59个病变。 44 个病变涉及 WT。间质型 WT 显示新辅助化疗后体积减少的中值最低（48.1cm3，范围 561.5-( )332.7cm3，p=0.035）。在通过切割导板直接关联后的显微载玻片水平（n = 240载玻片）上，与上皮和胚层病灶相比，基质区域显示出显着更高的中位ADC值（p< 0.001）。截止值为 1.195 * 10-3 mm2/s，敏感性和特异性分别为 95.2%（95% 置信区间 87.6-98.4%）和 90.5%（95% 置信区间 68.2-98.3%）。通过患者特异性 3D 打印切割导板在组织病理学和 MR-DWI 之间进行分析，可显着区分间质型 WT 与上皮亚型和胚芽亚型。基于高表观扩散系数值，可以将间质维尔姆斯肿瘤与上皮病变和胚芽病变区分开来新辅助化疗后体积减少有限。这可能有助于未来的决策，特别是在区分低风险和高风险肿瘤方面。MR-DWI 显示出作为儿童肾肿瘤非侵入性生物标志物的潜在价值。患者特定的切割指南导致表观扩散系数值与维尔姆斯肿瘤亚型之间存在相关性。根据表观扩散系数值，可以将间质区域与维尔姆斯肿瘤中的上皮和胚层病灶区分开来。© 2024。作者。

The International Society of Paediatric Oncology-Renal Tumour Study Group (SIOP-RTSG) discourages invasive procedures to determine the histology of paediatric renal neoplasms at diagnosis. Therefore, the histological subtype of Wilms' tumours (WT) is unknown at the start of neoadjuvant chemotherapy. MR-DWI shows potential value as a non-invasive biomarker through apparent diffusion coefficients (ADCs). This study aimed to describe MR characteristics and ADC values of paediatric renal tumours to differentiate subtypes.Children with a renal tumour undergoing surgery within the SIOP-RTSG 2016-UMBRELLA protocol were prospectively included between May 2021 and 2023. In the case of a total nephrectomy, a patient-specific cutting guide based on the neoadjuvant MR was 3D-printed, allowing a correlation between imaging and histopathology. Whole-tumour volumes and ADC values were statistically compared with the Mann-Whitney U-test. Direct correlation on the microscopic slide level was analysed through mixed model analysis.Fifty-nine lesions of 54 patients (58% male, median age 3.0 years (range 0-17.7 years)) were included. Forty-four lesions involved a WT. Stromal type WT showed the lowest median decrease in volume after neoadjuvant chemotherapy (48.1 cm3, range 561.5-(+)332.7 cm3, p = 0.035). On a microscopic slide level (n = 240 slides) after direct correlation through the cutting guide, stromal areas showed a significantly higher median ADC value compared to epithelial and blastemal foci (p < 0.001). With a cut-off value of 1.195 * 10-3 mm2/s, sensitivity, and specificity were 95.2% (95% confidence interval 87.6-98.4%) and 90.5% (95% confidence interval 68.2-98.3%), respectively.Correlation between histopathology and MR-DWI through a patient-specific 3D-printed cutting guide resulted in significant discrimination of stromal type WT from epithelial and blastemal subtypes.Stromal Wilms' tumours could be discriminated from epithelial- and blastemal lesions based on high apparent diffusion coefficient values and limited decrease in volume after neoadjuvant chemotherapy. This may aid in future decision-making, especially concerning discrimination between low- and high-risk neoplasms.MR-DWI shows potential value as a non-invasive biomarker in paediatric renal tumours. The patient-specific cutting guide leads to a correlation between apparent diffusion coefficient values and Wilms' tumour subtype. Stromal areas could be discriminated from epithelial and blastemal foci in Wilms' tumours based on apparent diffusion coefficient values.© 2024. The Author(s).