Estimating the need for neck lymphadenectomy in submucosal esophageal cancer using superparamagnetic iron oxide-enhanced magnetic resonance imaging: clinical validation study.

Background: In cases of thoracic esophageal cancer, multidirectional lymphatic flow from the tumor means that lymph node metastasis can occur in an area extending from the neck to the abdomen. To validate a method for limiting the performance of three-field lymphadenectomy only to patients who need it, we carried out a prospective study in which superparamagnetic iron oxide (SPIO)-enhanced lymphatic mapping was used to determine whether to perform neck lymph node dissection in patients with submucosal thoracic esophageal cancer.

Methods: A total of 22 patients with clinically submucosal thoracic squamous cell esophageal cancer, without neck lymph node metastasis, were enrolled. SPIO was endoscopically injected into the peritumoral submucosal layer, after which its appearance in lymph nodes in the neck was evaluated using magnetic resonance imaging (MRI). Neck lymph nodes were then dissected based on the SPIO-enhanced MRI lymphatic mapping.

Results: Influx of SPIO into lymph nodes was detected in 21 patients (95% detection rate). SPIO flowed to the neck in 8 (36%) patients. Influx of SPIO into neck lymph nodes was unilateral in five patients and bilateral in three patients, and the lymph nodes were dissected accordingly. A cancer-involved node was identified in two of those patients. In 14 patients, we did not dissect neck nodes. Patients were followed up for 6 to 47 months. The neck lymph node recurrence rate was zero, and the overall recurrence rate was 5%.

Conclusions: SPIO-enhanced lymphatic mapping may be useful for estimating the need for three-field lymphadenectomy with neck dissection.