Fig. 3From: Interobserver variability in target volume delineation in definitive radiotherapy for thoracic esophageal cancer: a multi-center study from ChinaThe routine group (RG; a) of clinical target volumes (CTVs) from 16 clinicians and the protocol group (PG; b) of CTVs from nine clinicians projected on one digitally reconstructed radiograph (DDR) of a CT dataset. Red and green areas indicate the primary tumor and lymph nodes, respectivelyBack to article page