Guidelines for the Delineation of Nodal Regions of the Head and Neck on Axial Computed Tomography Images

Abstract

Delineation of target volumes is increasingly recognized as the most crucial step within the process of modern conformal radiotherapy. In the field of head and neck radiation oncology, the need for a standardized methodology in the delineation of nodal regions of the neck on computed tomography (CT) images has recently emerged. To address this issue, a consensus document has been prepared by the Head and Neck Working Party of the AIRO-Lombardia Cooperative Group, based on the proceedings of multidisciplinary meetings and on literature findings. The document contains detailed guidelines for the delineation on CT images of the nodal regions of the neck, including for each nodal region (1 to 7) the description of anatomical limits as seen on CT images.

Further Improvement in Outcomes of Nasopharyngeal Carcinoma With Optimized Radiotherapy and Induction Plus Concomitant Chemotherapy: An Update of the Milan Experience

“…Typically, several apparently normal structures adjacent to the primary lesion and the majority of clinically negative neck nodal regions were included in this larger PTV, which also included a 3-mm setup margin (i.e., the expansion from low-dose CTV to low-dose PTV). The drawing of nodal regions included in the low-dose PTV was strictly based on the available guidelines (19,20). In general, nodal levels from 2 to 5 and retropharyngeal nodal regions were always included in the low-dose PTV, whereas submandibular (level IB) regions were included only in cases with bulky involvement of level IIA.…”