肺肿瘤热消融治疗的CT影像演变与疗效评价

CT manifestation evolution process of pulmonary tumors treated with thermal ablation and therapeutic evaluation

目的 分析肺肿瘤热消融治疗的CT影像表现及演变过程,探讨早期疗效评价的最佳时期和标准。方法 收集2017年1月至2020年6月浙江省肿瘤医院行肺肿瘤热消融治疗41例患者的临床资料,将患者分为完全消融组和不完全消融组。比较两组患者术后即刻、1、3、6、12个月的CT影像学特征,分析肺肿瘤热消融治疗后CT早期疗效评价的最佳时期和标准。结果 热消融术后即刻所有消融灶体积均较术前增大,病灶周围可见磨玻璃样阴影。完全消融组和不完全消融组患者磨玻璃样阴影最小宽度差异有统计学意义(P<0.05),诊断界值为3.9 mm时,AUC为0.871,敏感度为75.0%,特异度为90.3%。随时间延长,完全消融组患者消融灶体积逐渐缩小,最终表现为纤维条索、空洞、结节;不完全消融组患者消融灶体积先缩小后增大,呈结节或肿块样。两组患者术后1、3个月消融灶大小差异无统计学意义(P>0.05),术后6、12个月差异有统计学意义(P<0.05)。两组患者术后即刻平扫CT值均较术前降低,术后1、3个月消融灶增强后CT强化幅度差异无统计学意义(P>0.05);术后6、12个月差异有统计学意义(P<0.05),完全消融组表现为轻度强化(<10 HU),不完全消融组表现为不均匀明显强化(>15 HU)。结论 热消融术后即刻病灶周围磨玻璃样阴影最小宽度对疗效评价有较大的预测意义;消融灶大小变化和强化幅度是判断病灶治疗效果的主要影像指标;术后6个月是早期评价热消融治疗效果的最佳时期。

ObjectiveTo analyze the CT manifestation and its evolution process of pulmonary tumors treated with thermal ablation,and to explore the optimal period and criteria for early efficacy evaluation.MethodsThe clinical data of 41 patients with pulmonary tumor(51 lesions in total),who received thermal ablation treatment at the Zhejiang Provincial Cancer Hospital of China between January 2017 and June 2020,were collected.According to the expert consensus on thermal ablation therapy for primary and metastatic pulmonary tumor(2017 edition),the patients were divided into complete ablation group and incomplete ablation group.The postoperative instant,as well as the postoperative 1-,3-,6-,and 12-month CT image manifestations were compared between the two groups,and the optimal period to make evaluation of early efficacy and the evaluation criteria were analyzed.ResultsImmediately after the thermal ablation,the size of all lesions became larger than preoperative one,and ground-glass opacity(GGO)shadows could be observed around the ablated lesions.The difference in the minimum width of GGO between the two groups was statistically significant(P<0.05).When taking 3.9mm as the diagnostic cut-off value,the AUC was 0.871,the sensitivity was 75.0%,and the specificity was 90.3%.With time passing,in the complete ablation group the ablated lesion size gradually shrank,and the lesions eventually turned into fibrosis,cavities,and nodules,while in the incomplete ablation group the ablated lesion size shrank at first then enlarged,presenting as nodule or mass in shape.There was no significant difference in the postoperative 1-month and 3-month ablated lesion size between the two groups(P>0.05),but the difference in the postoperative 6-month and 12-month ablated lesion size between the two groups was statistically significant(P<0.05).Postoperative instant lesion's CT value on plain CT images was lower than preoperative one.On postoperative 1-month and 3-month enhanced CT imaging,the difference in the enhancement degree of the ablated lesion between the two groups was not statistically significant(P>0.05),but,this difference between the two groups became statistically significant on postoperative 6-month and 12-month enhanced CT images(P<0.05).In the complete ablation group the ablated lesions showed mild enhancement(CT value<10 HU),while in the incomplete ablation group the ablated lesions showed obviously uneven enhancement(CT value>15 HU).ConclusionPost-ablation instant minimum width of GGO shadow around the ablated lesion has a great predictive value for the efficacy evaluation.The changes of ablated lesion size and the enhancement degree of lesion are the main imaging indicators for judging the therapeutic effect.Six months after ablation is the optimal period for making the early evaluation of the curative effect of thermal ablation therapy.