通过磁共振成像（MRI）引导的肾肿瘤经皮冷冻消融手术后术中术前和术后MRI评估体积消融边缘，并探索其与局部治疗成功的相关性。对于在2014年5月至2020年5月期间接受经皮MRI引导的冷冻消融治疗的30名患者（平均年龄69岁）的32个肾肿瘤（大小为1.6-5.1厘米）进行了回顾性分析。使用SAFIR软件对术中术前和术后MR图像上的肿瘤和冰球体积进行了分割。MRI-MRI配准后，软件自动量化了最小治疗边缘（MTM），其定义为肿瘤和冰球表面之间的最小三维距离。通过随访影像评估冷冻消融后的局部肿瘤进展（LTP）。中位随访时间为16个月（范围为1-58个月）。在26例（81％）中实现了冷冻消融后的局部控制，而在6例（19％）中发生LTP。在32个病例中，只有3例（9％）达到了预期的MTM ≥5毫米。对于具有LTP（中位数为-7毫米，IQR：-10至-5）与不具有LTP（中位数为3毫米，IQR：2至4）的病例，MTM中位数明显较小（P<.001）。所有LTP病例均具有负MTM。所有负治疗边缘都出现在> 3厘米的肿瘤中。从术中MRI中确定体积消融边缘是可行的，并且可能有助于预测MRI引导肾冷冻消融后的局部结果。在我们的初步数据中，术中MRI获得的最小边缘延伸至MRI可见肿瘤之外至少1毫米，可导致局部控制，而在> 3厘米的肿瘤中更难实现。最终，在线边缘分析可能是评估治疗成功的有价值的工具，但需要更大规模的前瞻性研究以建立可靠的临床使用阈值。©2023. 作者（们）。

To assess volumetric ablation margins derived from intraoperative pre- and post-ablation MRI after magnetic resonance imaging (MRI)-guided percutaneous cryoablation of renal tumors and explore its correlation with local treatment success.Retrospective analysis was performed on 30 patients (mean age 69y) who underwent percutaneous MRI-guided cryoablation between May 2014 and May 2020 for 32 renal tumors (size: 1.6-5.1 cm). Tumor and ice-ball volumes were segmented on intraprocedural pre- and post-ablation MR images using Software Assistant for Interventional Radiology (SAFIR) software. After MRI-MRI co-registration, the software automatically quantified the minimal treatment margin (MTM),defined as the smallest 3D distance between the tumor and ice-ball surface. Local tumor progression (LTP) after cryoablation was assessed on follow-up imaging.Median follow-up was 16 months (range: 1-58). Local control after cryoablation was achieved in 26 cases (81%) while LTP occurred in 6 (19%). The intended MTM of ≥5 mm was achieved in 3/32 (9%) cases. Median MTM was significantly smaller for cases with (- 7 mm; IQR:-10 to - 5) vs. without LTP (3 mm; IQR:2 to 4) (P < .001). All cases of LTP had a negative MTM. All negative treatment margins occurred in tumors > 3 cm.Determination of volumetric ablation margins from intraoperative MRI was feasible and may be useful in predicting local outcome after MRI-guided renal cryoablation. In our preliminary data, an intraoperative MRI-derived minimal margin extending at least 1 mm beyond the MRI-visible tumor led to local control and this was more difficult to achieve in tumors > 3 cm. Ultimately, online margin analysis may be a valuable tool to intraoperatively assess therapy success, but larger prospective studies are needed to establish a reliable threshold for clinical use.© 2023. The Author(s).