| 摘要: |
| 目的 探索超声可视化肝内定位标记物作为射频消融术中肿瘤位置及安全边界的参照，精准指导消融范围以避免肝肿瘤因射频布针定位不准确而局部复发。方法 本实验纳入24种医用材料作为标记物，包括1种气体、18种液体、5种固体。体外实验采用离体牛肝，超声引导下于牛肝内置入可视化定位标记物，评估标记物的超声可视性及持久性；分别以射频电极针与标记物1cm、0.5cm、0cm的距离进行局部消融，分析射频热场对标记物的影响。动物实验采用超声引导下于活体比格犬肝内置入可视化定位标记物，分析肝内血流灌注、呼吸、心跳及射频消融的热沉效应对标记物的影响；观察消融后7 天内并发症发生情况，通过射频灶处犬肝组织观察标记物位置及肝组织损伤情况。结果 体外实验显示，空气、明胶海绵、PGA可吸收手术缝线、5 mm金属、声诺维-F127、海藻酸钙、超声耦合剂、聚桂醇的超声可视性及持久性均较好。标记物距消融针0.5 cm、1.0 cm进行射频消融后，各种标记物在二维超声图像中均可清晰显示，不受消融热场影响；紧贴消融针进行射频消融后，仅金属、海藻酸钙可见彗星尾征或后方衰减。动物实验中于犬肝内置入空气、PGA可吸收手术缝线、5mm金属、超声耦合剂4种材料，结果显示其超声可视性及持久性均较好。射频消融后即刻二维超声示上述4种材料标记物均可见，7 天后复查超声示金属仍清晰显示,大体标本示仅置入金属肉眼可见。穿刺置入过程中实验犬呼吸、心跳平稳，7天内均未发生出血、感染等并发症,病理组织学检查示肝组织未见损伤。结论 气体标记在超声下显示清晰持久，材料容易获取，控制注射速度及注射量等条件有望作为临床应用的定位标记物，指导适形消融。耦合剂及声诺维-F127与肝背景回声差异明显，作为肝内标记可能成为其临床新用途。金属标记射频后能够稳定保留，可作为肿瘤长期定位的理想标记。 |
| 关键词: 超声检查 定位标记 射频消融 肝肿瘤 |
| DOI： |
| 投稿时间：2023-09-28修订日期：2024-02-04 |
| 基金项目:国家自然科学基金(81971718)；北京市自然科学基金(7222020)；Science Foundation of Peking University Cancer Hospital （XKFZ2307） |
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| Study of Intraheptic Location Markers for Ultrasound-guided Radiofrequency Ablation in Tumors |
| SHEN Yu-han,WANG Bing,ZHAO Kun,WU Hao,WANG Song,YAN Kun,YANG Wei |
| (Department of Ultrasound,Peking University Cancer Hospital,Peking University Cancer Hospital Institute,Key Laboratory of Carcinogenesis and Translational Research Ministry of Education/Beijing) |
| Abstract: |
| Objective To explore ultrasound visualized intrahepatic localization marker as the reference object of the tumor location and safety margin in radiofrequency ablation（RFA）, aiming at precisely guiding ablation region to prevent from tumor local recurrence caused by inaccurate electrode needle placements. Methods A total of 24 medical materials were selected in this study, including 1 gas, 18 liquids, and 5 solids. In bovine liver experiment in vitro，ultrasound-guided puncture was performed and localization markers were inserted or injected into the bovine liver. Then the visibility and persistence in situ of the markers were evaluated using ultrasound images. Further，local ablation was performed at a distance of 1cm, 0.5cm and 0cm between the radiofrequency electrode needle and the markers，monitoring the effect of the thermal field on the markers. In animal models, visualized localization markers were put into the liver of living beagle dogs under the guidance of ultrasound to observe the effect of liver blood perfusion, breath, heartbeat as well as the heat-sink effect in ablation on the markers. The animals were observed for 7 days after RFA recording complications and reexamined by ultrasound on the 7th day. Then the ablation sites were dissected to observe the markers location and the damage of the liver tissue. Results In vitro experiments showed that air, sodium bicarbonate, gelatin sponge, PGA absorbable suture, 5 mm metal, SonoVue-F127，calcium alginate, ultrasonic couplant, lauromacrol had both good ultrasound visibility and persistence. After radiofrequency ablation, at 0.5 cm and 1.0 cm away from the ablation needle, various markers can be clearly displayed in ultrasound images without being affected by ablation thermal field. Close to the ablation needle, only metal and calcium alginate could still be seen by comet tail sign or backward attenuation. In animal experiments, air, PGA absorbable suture, 5mm metal and ultrasonic couplant were implanted into the dog liver and showed good ultrasound visibility and persistence. Immediately after radiofrequency ablation, all of the above four material markers were visible by ultrasound. 7 days later, reexamination showed that the metal was still clearly displayed by ultrasound, and gross specimens showed that only the implanted metal was visible macroscopically. The breathing and heartbeat of the dogs were stable during the puncture implantation, and no complications such as bleeding and infection occurred within 7 days. No liver tissue damage was noted in histopathological examination. Conclusion The gas marker with clear and durable visibility and simple availability，while controlling injection speed and dosage，is expectably served as a location marker to guide precise ablation needle placements. As to the couplant and the SonoVue-F127 showing obvious difference with hepatic background echo, intrahepatic marker may become a new clinical application. The metal marker could be stably retained in situ after RFA making it an ideal marker for long-term tumor localization. |
| Key words: Ultrasound examination Location marker Radiofrequency ablation Liver tumors |
