MRI在直肠癌新辅助治疗疗效评估中的价值

MR imaging in the evaluation of tumor response after neoadjuvant chemoradiotherapy for patients with rectal cancers

直肠癌新辅助放化疗可使肿瘤出现不同程度的消退,部分病灶甚至可以达到病理完全缓解,从而提高外科手术切除率,降低局部复发率。对肿瘤新辅助治疗疗效的准确评估,是选择个体化治疗方案的关键。磁共振成像对于直肠癌术前分期的价值得到广泛认可,其在新辅助治疗疗效评估中的作用仍在持续研究中。肿瘤体积测量是传统的应用评价指标,但繁琐的测量与计算过程一定程度上限制了其临床应用。多种功能成像序列的发展,为新辅助放化疗后疗效评估提供了更多更有效的选择方式。尽管如此,MRI对于分辨极少量残存的肿瘤细胞仍具有一定的困难,尤其是对于治疗后肿瘤完全缓解的评价,尚有待进一步研究与探索。

Multidisciplinary management of rectal cancer has evolved significantly, leading to theparticular importance of neoadjuvant therapy. Concurrently improving the resectability, neoadjuvant therapymay lead to an effective tumor down-staging of locally advanced rectal cancer in varying degrees. It issignificant to assess tumor response after neadjuvant therapy for altering the subsequent treatment options thatare considered. Magnetic resonance imaging is the recommended imaging technique for local staging of rectalcancer before surgery, and the role which plays in evaluation of response to neoadjuvant therapy is still understudy. The value of conventional MR depends on morphological changes in assessment of therapeutic effect.Nevertheless, there are still some limitations. Functional MR combines information of detailed anatomywith that of tumor biology, providing comprehensive status on tumor morphological features, quantitative indicators and their changes as a result of treatment. It has the potential to assess the response to neoadjuvanttherapy more accurately.