Atlas-based semiautomatic target volume definition (CTV) for head-and-neck tumors.

Purpose: To develop a new semiautomatic method to improve target delineation in head-and-neck cancer.

Methods And Materials: We implemented an atlas-based software program using fourteen anatomic landmarks as well as the most superior and inferior computerd tomography slices for automatic target delineation, using an advanced laryngeal carcinoma as an example. Registration was made by an affine transformation.