Khullar Karishma, Dhawan Survandita Tara, Nosher John, Jabbour Salma K
Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, USA.
Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA.
AME Case Rep. 2021 Apr 25;5:15. doi: 10.21037/acr-20-153. eCollection 2021.
Radiation therapy for liver tumors has been shown to provide a local control and overall survival benefit in patients with primary or oligometastatic liver tumors. However, accurate delineation of the target volume in intraabdominal tumors can be limited by diaphragmatic motion. In addition to image guidance during radiation therapy, computed tomography (CT)-guided fiducial marker placement can improve the accuracy of radiation treatment and optimize tumor control. Fiducial marker placement is often indicated in stereotactic body radiation therapy (SBRT) due to the ablative doses used as well as in proton therapy given that these markers are clearly visible on orthogonal kV image guidance and studies have suggested that their placement in liver tumors offers improved local control. However, fiducial marker migration is a rare risk associated with fiducial placement for which literature remains scarce. We report two separate cases of fiducial marker migrations from the liver into the inferior vena cava and right atrium which occurred following CT-guided placement without any resultant toxicity. Imaging using contrast-enhanced or volume navigation ultrasound techniques during fiducial marker deployment may mitigate the risk of fiducial marker migration and potential end-organ injury. Alternative techniques for motion management such as inspiratory or expiratory breath hold or use of residual lipiodol on imaging in patients who have undergone transarterial chemoembolization (TACE) should be considered as well to avoid potential complications from fiducial marker placement.
对于原发性或寡转移性肝肿瘤患者，放射治疗已被证明可带来局部控制和总生存获益。然而，腹内肿瘤靶区体积的精确勾画可能会受到膈肌运动的限制。除了放射治疗期间的图像引导外，计算机断层扫描（CT）引导下放置基准标记物可提高放射治疗的准确性并优化肿瘤控制。由于立体定向体部放射治疗（SBRT）使用的消融剂量以及质子治疗中这些标记物在正交千伏图像引导下清晰可见，且研究表明在肝肿瘤中放置这些标记物可改善局部控制，因此基准标记物放置常用于SBRT和质子治疗。然而，基准标记物迁移是与标记物放置相关的一种罕见风险，相关文献仍然很少。我们报告了两例在CT引导放置后基准标记物从肝脏迁移至下腔静脉和右心房的独立病例，且均未产生任何毒性。在放置基准标记物期间使用对比增强或容积导航超声技术成像，可能会降低基准标记物迁移和潜在终末器官损伤的风险。对于接受过经动脉化疗栓塞（TACE）的患者，还应考虑采用吸气或呼气屏气等替代运动管理技术，或在成像时使用残留的碘油，以避免基准标记物放置带来的潜在并发症。
