Guide for Delineation of Lymph Nodal Clinical Target Volume

Conformal radiotherapy offers the opportunity to enhance precise delivery of high dose radiation to the target volume while maintaining normal tissues doses at acceptable tolerance levels. This technique requires an exact definition of the treatment volumes: gross tumour volume (GTV), clinical target volume (CTV) and planning target volume (PTV). For this reason, it is important to have a very good knowledge of radiological anatomy and natural history of the disease.In particular, CTV is a tissue volume that contains the macroscopic disease with the surrounding areas suspected of subclinical involvement (CTV) and regional lymph nodes (CTV2). Delivery of adequate doses of irradiation to lymph nodes at risk, enhances treatment outcome and selective irradiation of them decreases morbitidy and yields better quality of life.To facilitate the understanding of cross-sectional anatomy detail and to assist Radiation Oncologists on the difficult task of a detailed delineation of lymph node targets in multiple anatomical locations, the editors compiled this work.