A Guide for Delineation of Lymph Nodal Clinical Target Volume in Radiation Therapy

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.

The book opens with a brief overview of the anatomy of the lymphatic system, followed by the main anatomical classifications involving lymph drain in four main regions (head and neck, mediastinum, superior abdomen, pelvis) and describes the spreading patterns of the different cancers. Based on close collaboration between Radiologists and Radiation Oncologists, explicit instructions for lymph nodal clinical target volumes delineation are proposed to obtain a more accurate and consistent definition of these volumes of interest; axial topographic reference points for anatomical boundaries of regional lymph nodes are presented in illustrative tables.  A folding page, containing of one side the anatomical-radiological tables and on the other the CT axial images, will facilitate the reading of CT images reported in the book from the head and neck region to the pelvic one.

The ediors hope that this book will be a valuable aid in accurate image based radiation therapy treatment planning for young as well as for more experienced Radiation Oncologists.