直肠癌术前放化疗疗效的影像学评价

Imaging evaluation of response of rectal cancer to preoperative chemoracliotherapy

术前放化疗是目前常用的提高直肠癌患者根治性切除率和肿瘤局部控制率的治疗方法。但直肠癌患者对放化疗的反应性不尽相同。目前临床影像学亟待解决的问题在于如何准确评价术前放化疗疗效和能否早期发现对放化疗不敏感的患者。MRI已经可以较为准确地进行直肠癌术前分期，有效地评价术前放化疗疗效。磁共振扩散加权成像（DWI）和PET-CT等功能成像方法在早期评价直肠癌术前放化疗疗效方面已显示出其应用前景，但在临床广泛应用尚需时日。

In recent years, preoperative therapy has become the standard procedure to improve radical resection rate and local control for advanced rectal cancer. Tumor responses to chemoradiotherapy, however, vary considerably, thus increasing the demand for both functional and morphologic radiologic evaluation of response to chemoradiotherapy to distinguish responders from nonresponders. MR imaging is considered the most accurate tool for the primary staging of tumor extent, and can he used to evaluate the efficacy of chemoradiotherapy. Functional imaging modalities including DW-MRI and PET-CT have shown promising prospect in the early evaluation of the response of rectal cancer to preoperative chemoradiotherapy. However, wide clinical application will take some time.