[Radiochemotherapy for esophageal cancer: which nodes should be irradiated?]

Abstract

Esophageal cancer has a high likelihood of distant lymphatic spread even at an early stage. Radiotherapy plays a major role in the management of localized or locally-advanced esophageal cancer with a regional or distant lymph node involvement. Radiotherapy can sterilize micrometastatic nodes and cancer cells in transit in the peri-esophageal fat that are not removed by surgery. After preoperative chemoradiotherapy followed by monobloc esophagectomy including lymph node dissection above and below the diaphragm, the locoregional failure rate was around 3% in the Chemoradiotherapy for Esophageal Cancer followed by Surgery Study Group (CROSS) trial. This is significantly lower than that observed with surgery alone or following exclusive chemoradiotherapy delivering 50 Gy over 5 weeks. Patterns of failure usually combine local and nodal failure. These results suggest that: (1) radiotherapy plays a major role in the management of micrometastatic nodes that are not removed by surgery; (2) the total dose of radiotherapy without surgery may be too low to control macroscopic disease. Better knowledge of regional failure sites and the enhancement of clinical practices through homogenized nodal radiotherapy could lead to a decrease in regional relapses, but at the expense of irradiated volumes greater than the macroscopic tumor volume. Intensity-modulated radiotherapy or volumetric modulated arctherapy makes it possible to increase mediastinal irradiated volumes while effectively protecting healthy tissues.

Keywords: Cancer de l’œsophage; Elective nodal irradiation; Esophageal cancer; Irradiation prophylactique ganglionnaire; Nodal failures; Radiotherapy; Radiothérapie; Rechutes ganglionnaires; Target volumes; Volumes cibles.