Bo Xiao-Wan, Xu Hui-Xiong, Guo Le-Hang, Sun Li-Ping, Li Xiao-Long, Zhao Chong-Ke, He Ya-Ping, Liu Bo-Ji, Li Dan-Dan, Zhang Kun, Wang Dan
1 Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Shanghai, China.
2 Ultrasound Research and Education Institute, Tongji University School of Medicine, Shanghai, China.
Br J Radiol. 2017 Oct;90(1078):20170063. doi: 10.1259/bjr.20170063. Epub 2017 Jul 27.
To evaluate the value of fusion imaging with post-treatment contrast-enhanced ultrasound (CEUS) and pre-treatment contrast-enhanced CT/MRI (CECT/CEMRI) in evaluating ablative safety margin after percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) for liver cancers.
34 consecutive patients with 47 liver lesions who had undergone RFA were included. Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI was carried out to evaluate local treatment response and ablative safety margin within 1-3 days after RFA. The minimal ablative safety margins of the ablation zones were recorded. The complete response (CR) rate was calculated with reference to CECT/CEMRI results 1 month after RFA. The local tumour progression (LTP) was also recorded.
Of the 47 ablation zones, 47 (100%) were clearly depicted with CEUS-CECT/CEMRI fusion imaging, 36 (76.6%) with US-CECT/CEMRI fusion imaging and 21 (44.7%) with conventional US (both p < 0.001). The minimal ablative safety margins were great than or equal to 5 mm in 28 ablation zones, between 0 and 5 mm in 15, and less than 0 mm in 4. For the four lesions without enough ablative safety margin, three were referred to follow-up because CEUS showed larger ablation zones than pre-treatment lesions and the remaining lesion was subject to additional RFA 5 days after the first RFA. The CR rate was 95.7% (45/47) with reference to CECT/CEMRI results 1 month after RFA. During 2 to 34 months follow-up, LTP was found in two (4.4%) of 45 lesions with CR. Insufficient ablative safety margin was more commonly found in those lesions with LTP than those without LTP (1/4 vs 1/43, p < 0.001).
Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI can depict the ablative safety margin accurately after RFA. Inadequate ablative safety margin is associated with LTP. Depiction of ablative safety margin by fusion imaging after ablation might be considered as a routine procedure to assess the treatment response of RFA. Advances in knowledge: Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI is an effective method to evaluate the ablative safety margin early after RFA. Therefore, it should be recommended to be used as a routine procedure after RFA for liver cancers.
评估治疗后对比增强超声（CEUS）与治疗前对比增强CT/MRI（CECT/CEMRI）融合成像在评估经皮超声（US）引导下肝癌射频消融（RFA）术后消融安全边缘中的价值。
纳入34例连续的患者，共47个肝脏病灶，均接受了RFA治疗。在RFA术后1至3天内，采用治疗后CEUS与治疗前CECT/CEMRI融合成像来评估局部治疗反应及消融安全边缘。记录消融区的最小消融安全边缘。参照RFA术后1个月的CECT/CEMRI结果计算完全缓解（CR）率。同时记录局部肿瘤进展（LTP）情况。
在47个消融区中，CEUS-CECT/CEMRI融合成像清晰显示了47个（100%），US-CECT/CEMRI融合成像显示了36个（76.6%），而传统超声显示了21个（44.7%）（均p<0.001）。28个消融区的最小消融安全边缘大于或等于5mm，15个在0至5mm之间，4个小于0mm。对于4个消融安全边缘不足的病灶，3个因CEUS显示消融区大于治疗前病灶而进行随访，另1个病灶在首次RFA术后5天接受了再次RFA治疗。参照RFA术后1个月的CECT/CEMRI结果，CR率为95.7%（45/47）。在2至34个月的随访中，45个CR病灶中有2个（4.4%）出现LTP。与无LTP的病灶相比，LTP病灶更常见消融安全边缘不足（1/4 vs 1/43，p<0.001）。
治疗后CEUS与治疗前CECT/CEMRI融合成像能够准确显示RFA术后的消融安全边缘。消融安全边缘不足与LTP相关。消融后通过融合成像描绘消融安全边缘可被视为评估RFA治疗反应的常规操作。知识进展：治疗后CEUS与治疗前CECT/CEMRI融合成像是早期评估RFA术后消融安全边缘的有效方法。因此，建议将其作为肝癌RFA术后的常规操作使用。
