使用可喷雾的pH激活荧光团对喉部肿瘤进行快速离体可视化

文献信息

中文摘要

引言： 在喉部和下咽部肿瘤切除术中，实现清晰的切除边缘（> 5 mm）至关重要，因为阳性边缘与疾病特异性生存率降低相关。近红外（NIR）荧光成像已成为术中边缘评估的重要工具，能够实时可视化残留肿瘤组织。然而，目前的荧光造影剂依赖静脉给药，通常需要在手术前数小时至数天给药。此外，靶向表达异质性的肿瘤特异性生物标志物限制了其适用性。为解决这些局限性，我们评估了局部应用的pH激活荧光团（PH10）的可行性，该荧光团在酸性条件下选择性发出荧光。这项离体概念验证研究探讨了局部应用PH10能否可视化喉部和下咽部肿瘤。
方法： 从十名患者中获取新鲜切除的喉部和下咽部鳞状细胞癌（SCC）标本，并在手术后立即局部喷洒PH10。孵育2分钟后，在三次连续生理盐水冲洗前后获取近红外荧光图像。荧光强度以肿瘤与背景比值（TBR）量化；肿瘤定位经组织病理学确认。
结果： 喉部肿瘤在应用PH10后表现出肿瘤特异性荧光，肿瘤组织中的信号强度显著高于邻近正常黏膜（P < 0.05）。第一次冲洗后的中位TBR为2.3（四分位距1.7-3.0），在七例喉部SCC病例中有七例超过了临床相关阈值1.5；然而，在纳入的两例下咽部癌病例中均未达到该阈值。
结论： 这项概念验证研究表明，PH10作为一种可喷雾的pH激活荧光团，能够实现喉部肿瘤的快速和高对比度可视化，尽管在评估的少量下咽部病例中未观察到这一效果。鉴于其局部应用和快速激活的特点，PH10可能有望用于术中边缘评估，但这些基于小样本和异质性样本的初步发现，需要在更大队列中验证，包括与深部切除边缘的直接相关性，才能确立其临床实用性。

英文摘要

INTRODUCTION: Achieving clear resection margins (> 5 mm) is critical during laryngeal and hypopharyngeal tumor resection, as positive margins are associated with reduced disease-specific survival. Near-infrared (NIR) fluorescence imaging has emerged as a valuable tool for intraoperative margin assessment by enabling real-time visualization of residual tumor tissue. However, current fluorescent contrast agents rely on intravenous administration, often requiring dosing hours to days before surgery. Also, targeting tumor-specific biomarkers with heterogeneous expression limits applicability. To address these limitations, we evaluated the feasibility of a topically applied pH-activatable fluorophore (PH10), which selectively fluoresces under acidic conditions. This ex vivo proof-of-concept study investigates whether topical PH10 can visualize laryngeal and hypopharyngeal tumors.
METHODS: Freshly resected laryngeal and hypopharyngeal squamous cell carcinoma (SCC) specimens were obtained from ten patients and topically sprayed with PH10 immediately after surgery. Following a 2-min incubation period, NIR fluorescence images were acquired before and after three sequential saline washes. Fluorescence intensity was quantified as the tumor-to-background ratio (TBR); tumor localization was confirmed on histopathology.
RESULTS: Laryngeal tumors demonstrated tumor-specific fluorescence upon PH10 application, with significantly higher signal intensity in tumor tissue compared to adjacent normal mucosa (P < 0.05). The median TBR after the first wash was 2.3 (interquartile range 1.7-3.0), exceeding the clinically relevant threshold of 1.5 in seven of seven laryngeal SCC cases; however, this threshold was not reached in either of the two hypopharyngeal carcinoma cases included.
CONCLUSIONS: This proof-of-concept study suggests that PH10, a sprayable pH-activatable fluorophore, can enable rapid and high-contrast visualization of laryngeal tumors, although this was not observed in the small number of hypopharyngeal cases evaluated. Given its topical application and rapid activation, PH10 may hold promise for intraoperative margin assessment, yet these preliminary findings, based on a small and heterogeneous sample, require validation in larger cohorts, including direct correlation with deep resection margins, before clinical utility can be established.