为了根据2015年美国甲状腺协会指南所提出的基于动态风险分层的消融后反应系统，以预测低危乳头状甲状腺微小癌（PTMC）患者的临床结果和指导随访策略，展开研究。本回顾性研究回顾了在2014年至2018年期间接受射频消融（RFA）治疗的低危PTMC患者。我们根据患者在1年随访时的治疗反应将患者分为三组：完全反应、不确定反应和不完全反应。主要终点是局部肿瘤进展（LTP）和无疾病生存（DFS）。在748名患者（平均年龄43.7岁±9.8；其中586名女性）中，4.0％（30/748）在5年的中位随访期内出现了LTP。患者中80.2％（600/748）的患者反应完全，18.1％（135/748）的患者反应不确定，1.7％（13/748）的患者反应不完全。最终随访中LTP率分别为1％（6/600），8.1％（11/135）和100％（13/13）。与完全反应组相比，不完全反应组（HR，1825.82；95％CI：458.27, 7274.36；p < 0.001）和不确定反应组（HR，8.12；95％CI：2.99, 22.09；p < 0.001）的LTP风险显著不同。各组间DFS也存在显著差异（p < 0.001）。该系统的变异比例和C指数均较高（分别为27.66％和0.79）。我们定义了一个消融反应系统，为接受RFA治疗的PTMC患者的管理提供了新的范式。我们的数据证实了该系统能够有效预测LTP风险并指导随访建议的持续进行。• 消融反应系统可以将接受RFA治疗的低危PTMC患者分为完全反应、不确定反应或不完全反应类别。• 结果表明，在这一人群中，该系统能够识别三个有着显著不同临床结果的患者亚群。• 消融反应系统将有助于更好地个体化持续的随访建议。 © 2023.作者/作者，根据欧洲放射学协会的独家许可。

To define a response-to-ablation system based on dynamic risk stratification proposed by the 2015 American Thyroid Association guidelines for predicting clinical outcomes and guiding follow-up strategies for patients with low-risk papillary thyroid microcarcinoma (PTMC) who underwent radiofrequency ablation (RFA).This retrospective study reviewed patients with low-risk PTMC who underwent RFA between 2014 and 2018. We classified patients into three groups based on their response to therapy at the 1-year follow-up: complete, indeterminate, and incomplete. The primary endpoints were local tumor progression (LTP) and disease-free survival (DFS).Among the 748 patients (mean age, 43.7 years ± 9.8; 586 women), 4.0% (30/748) had LTP during a median follow-up of 5 years. The response was complete in 80.2% (600/748) of the patients, indeterminate in 18.1% (135/748), and incomplete in 1.7% (13/748). The LTP rate in the final follow-up was 1% (6/600), 8.1% (11/135), and 100% (13/13), respectively. The risk of LTP was significantly different in the incomplete response group (HR, 1825.82; 95% CI: 458.27, 7274.36; p < 0.001) and indeterminate response group (HR, 8.12; 95% CI: 2.99, 22.09; p < 0.001) than in the complete response group. There were significant differences in DFS among groups (p < 0.001). The proportion of variation explained and C-index of the system was high (27.66% and 0.79, respectively).We defined a response-to-ablation system that provides a new paradigm for the management of patients with PTMC who underwent RFA. Our data confirm that the system can effectively predict the risk of LTP and guide ongoing follow-up recommendations.• The response-to-ablation system can classify patients with low-risk PTMC who underwent RFA into complete, indeterminate, or incomplete response categories. • Results suggest that, in this population, this system can identify three separate cohorts of patients who have significantly different clinical outcomes. • The response-to-ablation system will help better tailor the ongoing follow-up recommendations.© 2023. The Author(s), under exclusive licence to European Society of Radiology.