Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
Center for Human Drug Research, Zernikedreef 8, 2333 CL, Leiden, The Netherlands.
Eur J Nucl Med Mol Imaging. 2024 Aug;51(10):2970-2979. doi: 10.1007/s00259-023-06365-3. Epub 2023 Aug 8.
Metastasectomy is a common treatment option for patients with colorectal lung metastases (CLM). Challenges exist with margin assessment and identification of small nodules, especially during minimally invasive surgery. Intraoperative fluorescence imaging has the potential to overcome these challenges. The aim of this study was to assess feasibility of targeting CLM with the carcinoembryonic antigen (CEA) specific fluorescent tracer SGM-101.
This was a prospective, open-label feasibility study. The primary outcome was the number of CLM that showed a true positive fluorescence signal with SGM-101. Fluorescence positive signal was defined as a signal-to-background ratio (SBR) ≥ 1.5. A secondary endpoint was the CEA expression in the colorectal lung metastases, assessed with the immunohistochemistry, and scored by the total immunostaining score.
Thirteen patients were included in this study. Positive fluorescence signal with in vivo, back table, and closed-field bread loaf imaging was observed in 31%, 45%, and 94% of the tumors respectively. Median SBRs for the three imaging modalities were 1.00 (IQR: 1.00-1.53), 1.45 (IQR: 1.00-1.89), and 4.81 (IQR: 2.70-7.41). All tumor lesions had a maximum total immunostaining score for CEA expression of 12/12.
This study demonstrated the potential of fluorescence imaging of CLM with SGM-101. CEA expression was observed in all tumors, and closed-field imaging showed excellent CEA specific targeting of the tracer to the tumor nodules. The full potential of SGM-101 for in vivo detection of the tracer can be achieved with improved minimal invasive imaging systems and optimal patient selection.
The study was registered in ClinicalTrial.gov under identifier NCT04737213 at February 2021.
肺转移切除术是结直肠肺转移（CLM）患者的常见治疗选择。在微创手术中，存在切缘评估和小结节识别的挑战，尤其是在微创手术中。术中荧光成像是克服这些挑战的潜在手段。本研究的目的是评估针对结直肠癌细胞表面黏附分子（CEA）特异性荧光示踪剂 SGM-101 的 CLM 靶向的可行性。
这是一项前瞻性、开放标签的可行性研究。主要结局是 CLM 显示出与 SGM-101 具有真正阳性荧光信号的数量。荧光阳性信号定义为信号与背景比（SBR）≥1.5。次要终点是用免疫组织化学评估结直肠肺转移瘤中的 CEA 表达，并通过总免疫染色评分进行评分。
本研究纳入了 13 名患者。在体内、离体和闭场面包状成像中，分别有 31%、45%和 94%的肿瘤观察到阳性荧光信号。三种成像方式的中位 SBR 分别为 1.00（IQR：1.00-1.53）、1.45（IQR：1.00-1.89）和 4.81（IQR：2.70-7.41）。所有肿瘤病变的 CEA 表达最大总免疫染色评分为 12/12。
本研究表明，使用 SGM-101 对 CLM 进行荧光成像具有潜力。所有肿瘤均观察到 CEA 表达，闭场成像显示示踪剂对肿瘤结节的 CEA 特异性靶向作用良好。通过改进的微创成像系统和最佳的患者选择，可以实现 SGM-101 对体内示踪剂的充分检测潜力。
该研究于 2021 年 2 月在 ClinicalTrials.gov 上以标识符 NCT04737213 注册。
