From the Department of Radiology, Severance Hospital, Research Institute of Radiological Science (K.H.), and Biostatistics Collaboration Unit, Department of Biomedical Systems Informatics (M.L.), Yonsei University College of Medicine, Seoul, Korea; and Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro, 43-gil, Songpa-gu, Seoul, 138-736, Korea (J.H.K., S.G.Y., S.H.P., H.K.C., S.Y.C., P.N.K., J.P.).
Radiology. 2021 Jan;298(1):212-218. doi: 10.1148/radiol.2020200109. Epub 2020 Nov 10.
Background Local tumor progression (LTP) is associated with poorer survival in patients undergoing radiofrequency ablation (RFA) for colorectal liver metastasis (CLM). An algorithmic strategy to predict LTP may help in selection of patients who would benefit most from RFA for CLM. Purpose To estimate local tumor progression-free survival (LTPFS) following RFA of CLM and develop an algorithmic strategy based on clinical variables. Materials and Methods In this retrospective study, between March 2000 and December 2014, patients who underwent percutaneous RFA for CLM were randomly split into development (60%) and internal validation (40%) data sets. Kaplan-Meier method was used to estimate LTPFS and overall survival (OS) rates. Independent factors affecting LTPFS in the development data set were investigated by using multivariable Cox proportional hazard regression analysis. Risk scores were assigned to the risk factors and applied to the validation data set. Results A total of 365 patients (mean age, 60 years ± 11 [standard deviation]; 259 men) with 512 CLMs were evaluated. LTPFS and OS rates were 85% and 92% at 1 year, 73% and 41% at 5 years, 72% and 30% at 10 years, and 72% and 28% at 15 years, respectively. Independent risk factors for LTP included tumor size of 2 cm or greater (hazard ratio [HR], 3.8; 95% CI: 2.3, 6.2; < .001), subcapsular tumor location (HR, 1.9; 95% CI: 1.1, 3.1; = .02), and minimal ablative margin of 5 mm or less (HR, 11.7; 95% CI: 4.7, 29.2; < .001). A prediction model that used the risk factors had areas under the curve of 0.89, 0.92, and 0.90 at 1, 5, and 10 years, respectively, and it showed significantly better areas under the curve when compared with the model using the minimal ablative margin of 5 mm or less alone. Conclusion Radiofrequency ablation provided long-term control of colorectal liver metastases. Although minimal ablative margin of 5 mm or less was the most dominant factor, the multifactorial approach including tumor size and subcapsular location better predicted local tumor progression-free survival. © RSNA, 2020 See also the editorial by Soulen and Sofocleous in this issue.
背景 局部肿瘤进展（LTP）与接受射频消融（RFA）治疗结直肠癌肝转移（CLM）患者的生存率较差有关。预测 LTP 的算法策略可能有助于选择最受益于 RFA 治疗 CLM 的患者。目的 评估 RFA 治疗 CLM 后的局部肿瘤无进展生存率（LTPFS），并基于临床变量制定算法策略。材料与方法 本回顾性研究于 2000 年 3 月至 2014 年 12 月期间，将接受 CLM 经皮 RFA 治疗的患者随机分为开发（60%）和内部验证（40%）数据集。采用 Kaplan-Meier 法估计 LTPFS 和总生存率（OS）。采用多变量 Cox 比例风险回归分析，探讨开发数据集中影响 LTPFS 的独立因素。根据危险因素分配风险评分，并应用于验证数据集。结果 共评估了 365 例（平均年龄 60 岁±11[标准差]；259 例男性）患者的 512 个 CLM。1 年时 LTPFS 和 OS 率分别为 85%和 92%，5 年时分别为 73%和 41%，10 年时分别为 72%和 30%，15 年时分别为 72%和 28%。LTP 的独立危险因素包括肿瘤直径 2cm 或以上（危险比[HR]，3.8；95%CI：2.3，6.2；<0.001）、包膜下肿瘤位置（HR，1.9；95%CI：1.1，3.1；=0.02）和最小消融边界 5mm 或以下（HR，11.7；95%CI：4.7，29.2；<0.001）。使用危险因素的预测模型在 1、5 和 10 年时的曲线下面积分别为 0.89、0.92 和 0.90，与仅使用 5mm 或更小的最小消融边界的模型相比，其曲线下面积明显更大。结论 RFA 为结直肠癌肝转移提供了长期控制。虽然 5mm 或更小的最小消融边界是最主要的因素，但包括肿瘤大小和包膜下位置在内的多因素方法可以更好地预测局部肿瘤无进展生存率。©RSNA，2020 本期还刊登了 Soulen 和 Sofocleous 的相关述评。
