Dosimetric Comparison of two Methods of Three-Dimensional Conformal Radiotherapy and Helical Tomotherapy in Head and Neck Cancer Patients with Involvement of Regional Lymph Nodes

Head and Neck cancers remain a significant problem due to their high morbidity and mortality and in most cases, require regional lymph nodes radiotherapy treatment. This work aims to evaluate and compare two methods of Three-Dimensional Conformal Radiation Therapy (3D-CRT) and Helical Tomotherapy (HT) based on treatment planning and selection of the most appropriate method to reduce side effects.

In this study, 20 patients with head and neck cancers were considered for treatment in the radiotherapy department of Seyed Alshohada Hospital, Isfahan, Iran. Two methods of HT and 3D-CRT were done using a 6 MeV photon energy apparatus and specific treatment planning algorithms. The dose-volume distribution curve (DVH), the dosimetric variables of the target organ, the radiation delivery efficiency, and the organs at risk were determined and results were compared with each other.

In HT the dose received by %95 planning target volume (PTV) and value doses of %2 and %98 showed significant improvement over 3D-CRT. For all studied organs at risk (OARs), the decrease in Dmax of HT was significant compared to 3-DCRT.

Helical tomotherapy enhances the target volume coverage and offers a good dose distribution. HT compared to 3D-CRT is a desirable method in treating head and neck cancer patients with the involvement of regional lymph nodes.