消化系肿瘤分子影像诊断的研究进展

Advances in molecular imaging for diagnosis of digestive tract cancers

消化系肿瘤具有高发病、高死亡的特点,而现有检查手段难以实现早期、准确地诊断.分子影像以分子而非解剖结构为对象,提升检查的灵敏及特异性.消化系肿瘤分子影像涉及的成像方法包括光学内镜、闪烁扫描成像、磁共振、超声等.抗体、多肽、适体等均可作为特异性配体,经显像基团标记成为探针,实现对肿瘤细胞或间质的特异性结合及成像.这类技术不仅用于肿瘤早期诊断,还可协助肿瘤分期,指导治疗.随着新仪器及探针的开发,以及多元化显像模式的发展,分子影像已逐渐完善并从实验室进入临床,使更早期、全面、准确诊断消化系肿瘤成为可能.

Digestive tract cancers are common cancer types and have high incidence and mortality. Currently available diagnostic methods have some limitations that make an early and accurate diagnosis and prompt treatment difficult. Molecular imaging, which has been formally defined as visual- ization, characterization and measurement at the molecular level instead of the anatomic level, sig- nificantly increases the sensitivity and specificity of cancer detection. Several modalities have been utilized for molecular imaging in digestive tract cancers, such as endoscopy, scintigraphy （PET/ SPECT）, magnetic resonance imaging （MRI）,and ultrasound （US）. Antibodies, peptides, and aptamers are classes of molecular probes that have been extensively used as affinity ligands. After being conjugated with various labels such as radioisotopes, fluorophore, supermagnetic or paramagnetic metals and microbubbles, the probes can specifically target tumor cells and stroma and are used with imaging modalities to detect cancers. Molecular imaging is a methodol- ogy for not only the early detection of cancer, but also the judgment of tumor staging and the guidance of therapy. With the development of new instrument and probes, as well as multimodal platforms, molecular imaging has been gradually perfected and taken from bench to bedside, bringing opportunities for early, accurate and compre- hensive diagnosis of digestive tract cancers.