Preoperative evaluation of lymphovascular invasion using high-resolution pelvic magnetic resonance in patients with rectal cancer: a 2-year follow-up study.

Objectives: The objectives of this study were to preoperatively evaluate lymphovascular invasion (LVI) using pelvic magnetic resonance (MR) in patients with rectal cancer and to determine the correlation with distant metastasis rate.

Methods: If the mesorectal perivascular infiltrative signal was visible on pelvic MR imaging, the possibility of LVI was recorded. Distant metastatic lesions were also recorded at the time of the initial diagnostic workup and over a 2-year follow-up period.

Results: Fifteen (68.2%) of the 22 LVI patients showed mesorectal perivascular infiltrative signals on pelvic MRI. For the prediction of LVI in rectal cancer, MR had a sensitivity of 68.2% and a specificity of 93.2. The initial distant metastasis rate was significantly higher in patients with MR LVI (52%) than in patients without MR LVI (5.7%) (P < 0.0001).

Conclusions: On pelvic MR, the presence of mesorectal perivascular infiltration by nodes is a specific sign of LVI in rectal cancer, and the presence of LVI is a predictor of distant metastasis.