Department of Oral and Maxillofacial Surgery, Medical Center - University of Freiburg, Faculty of Medicine, Albert-Ludwigs University Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany.
Berta-Ottenstein-Programme for Clinician Scientists, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
BMC Med Imaging. 2021 Oct 27;21(1):157. doi: 10.1186/s12880-021-00689-y.
Intraoperative incorporation of radiopaque fiducial markers at the tumor resection surface can provide useful assistance in identifying the tumor bed in postoperative imaging for RT planning and radiological follow-up. Besides titanium clips, iodine containing injectable liquid fiducial markers represent an option that has emerged more recently for this purpose. In this study, marking oral soft tissue resection surfaces, applying low dose injections of a novel Conformité Européenne (CE)-marked liquid fiducial marker based on sucrose acetoisobutyrate (SAIB) and iodinated SAIB (x-SAIB) was investigated.
Visibility and discriminability of low dose injections of SAIB/x-SAIB (10 µl, 20 µl, 30 µl) were systematically studied at different kV settings used in clinical routine in an ex-vivo porcine mandible model. Transferability of the preclinical results into the clinical setting and applicability of DE-CT were investigated in initial patients.
Markers created by injection volumes as low as 10 µl were visible in CT imaging at all kV settings applied in clinical routine (70-120 kV). An injection volume of 30 µl allowed differentiation from an injection volume of 10 µl. In a total of 118 injections performed in two head and neck cancer patients, markers were clearly visible in 83% and 86% of injections. DE-CT allowed for differentiation between SAIB/x-SAIB markers and other hyperdense structures.
Injection of low doses of SAIB/x-SAIB was found to be a feasible approach to mark oral soft tissue resection surfaces, with injection volumes as low as 10 µl found to be visible at all kV settings applied in clinical routine. With the application of SAIB/x-SAIB reported for tumors of different organs already, mostly applying relatively large volumes for IGRT, this study adds information on the applicability of low dose injections to facilitate identification of the tumor bed in postoperative CT and on performance of the marker at different kV settings used in clinical routine.
在肿瘤切除表面掺入放射性不透射线的基准标记物可以为 RT 计划和放射学随访的术后成像中识别肿瘤床提供有用的帮助。除了钛夹之外，含碘的可注射液体基准标记物代表了最近出现的用于此目的的一种选择。在这项研究中，研究了在口腔软组织切除表面应用新型基于蔗糖乙酰异丁酸酯 (SAIB) 和碘代 SAIB (x-SAIB) 的符合欧洲规范 (CE) 的标记液体基准标记物的低剂量注射，以进行标记。
在离体猪下颌骨模型中，系统研究了在临床常规中使用的不同千伏设置下注射 SAIB/x-SAIB（10 μl、20 μl、30 μl）的低剂量注射的可见度和可分辨性。将临床前结果转移到临床应用，并初步研究了 DE-CT 的适用性。
在临床常规中应用的所有千伏设置（70-120 kV）下，体积低至 10 μl 的注射产生的标记物在 CT 成像中可见。30 μl 的注射体积可与 10 μl 的注射体积区分开来。在两名头颈部癌症患者中进行的总共 118 次注射中，83%和 86%的注射中标记物清晰可见。DE-CT 允许区分 SAIB/x-SAIB 标记物和其他高密度结构。
发现注射低剂量的 SAIB/x-SAIB 是一种可行的方法，可以标记口腔软组织切除表面，在临床常规应用的所有千伏设置下，体积低至 10 μl 的注射都可见。SAIB/x-SAIB 已应用于不同器官的肿瘤报告，主要应用于 IGRT 的相对较大体积，本研究提供了有关低剂量注射应用于识别术后 CT 中肿瘤床的信息，以及在临床常规中使用的不同千伏设置下标记物的性能信息。
