Molecular Lymphosonography for Sentinel Lymph Node Characterization

描述(由申请人提供)：对接受原发癌(如乳腺癌或黑色素瘤)引流的前哨淋巴结(SLN)的准确检测和表征对患者的治疗有直接影响。目前用于识别SLN的方法有两种：瘤周注射放射性同位素，然后进行核素扫描和注射染料进行检测。 在手术中发现染色的SLN。然而，这些方法中的每一种都有潜在的局限性，可能对SLN的检测和疾病分期的准确性产生不利影响。此外，同位素成像需要电离辐射，蓝色染料会引起过敏反应，这两种技术都不能提供准确的非侵入性淋巴解剖描述。我们小组已经证明，皮下注射组织特异性超声造影剂(UCA)后的对比增强超声成像(CEUS)可以用于非侵入性地定位淋巴引流和定位SLN(所谓的“淋巴超声造影术”)。美国国立卫生研究院资助的猪自然发生黑色素瘤模型的研究证实，CEUS优于放射性同位素成像，可以多检测出近20%的SLN。然而，淋巴超声诊断SLN恶性或良性的能力略逊于标准灰阶超声(分别为80%和86%)。CEUS的特异性通过使用靶向UCA来提高，其中靶向配体连接到试剂的表面以提高亲和力。因此，目前的提案将通过包括三靶向分子UCA来扩展淋巴超声成像的概念，以改善SLN的特征。我们推测，皮下淋巴探头和静脉(IV)注射三靶点UCA(靶向avb3整合素、P-选择素和VEGFR2)可以更好地检测SLN，并准确地定性为良性或转移性。在体外验证研究之后，将对20头携带黑色素瘤的猪进行研究，这些猪大约有125个SLN。将在每个黑色素瘤周围注射Res特异性UCA，以检测SLN。然后进行三靶点UCA(即分子淋巴超声)静脉注射，以确定是否有转移沉积。最后，在黑色素瘤周围注射蓝色染料，外科医生将切除染有染料的SLN，并将其提交给病理学，以确定它们是否包含转移。分子淋巴超声在SLN中发现肿瘤的准确性将与标准CEUS(即使用非靶向UCA)进行比较，并以病理为参考标准。这项创新研究的潜在好处将是开发一种微创成像方法(分子淋巴超声成像)来识别SLN并准确诊断转移性SLN受累，从而显著减少执行切除淋巴结活检的需要，减少与手术相关的并发症并改善患者预后。

DESCRIPTION (provided by applicant): Accurate detection and characterization of sentinel lymph nodes (SLNs) that receive drainage from a primary cancer (e.g., breast or melanoma) have a direct impact on patient management. Two methods are currently used to identify SLNs; peritumoral injection of radioisotopes followed by scintigraphy and injection of dye with detection of dye-stained SLNs at surgery. However, each of these methods has potential limitations that can adversely impact the detection of SLNs and the accuracy of disease staging. Furthermore, isotope imaging requires ionizing radiation, blue dye can cause anaphylactic reactions and neither of these techniques provides an accurate noninvasive depiction of lymphatic anatomy. Our group has demonstrated that contrast-enhanced ultrasound imaging (CEUS) after subdermal administration of a tissue-specific ultrasound contrast agent (UCA), can be used to noninvasively map lymphatic drainage and localize SLNs (so called "lymphosonography"). Our NIH funded investigations using a swine model with naturally occurring melanomas have confirmed that CEUS is superior to radioisotope imaging detecting almost 20 % more SLNs. However, the ability of lymphosonography to characterize SLNs as malignant or benign was slightly worse than that of standard grayscale ultrasound (80 % vs. 86 %, respectively). The specificity of CEUS improves with the use of a targeted UCA, in which targeting ligands are attached to the surface of the agent to improve affinity. Hence, the current proposal will expand on the concept of lymphosonography by including a triple-targeted molecular UCA to improve SLN characterization. We hypothesize that subdermal lymphosonogray followed by intravenous (IV) injection of a triple-targeted UCA (targeted to avb3 integrin, P-selectin and VEGFR2) will permit superior detection of SLNs as well as accurate characterization as benign or metastatic. Following an in vitro validation study, 20 melanoma-bearing swine with around 125 SLNs will be studied. An RES-specific UCA will be injected around each melanoma to permit detection of the SLNs. Then the triple-targeted UCA (i.e., molecular lymphosonography) will be injected IV and the presence or absence of metastatic deposits will be determined. Finally, blue dye will be injected around the melanoma and a surgeon will resect the dye-stained SLNs, which will be submitted to pathology to determine if they contain metastases. The accuracy of tumor detection in the SLNs identified by molecular lymphosonography will be compared to that of standard CEUS (i.e., using a non-targeted UCA) with pathology as the reference standard. The potential benefits of this innovative study will be the development of a minimally-invasive imaging method (molecular lymphosonography) to identify SLNs and accurately diagnose metastatic SLN involvement, thereby significantly reducing the need to perform excisional lymph node biopsies, reducing procedure-related complications and improving patient outcome.