Comparison of the Cochlea Dose in Head and Neck Cancer Patients Treated with 3-Dimensional Conformal Radiotherapy and Helical Tomotherapy

Head and neck cancer (HNC) is among the ten most common cancers worldwide. Due to the complex head and neck anatomy, many organs receive radiation during treatment. The aim of this study is to compare the cochlea dose in two different treatment methods, 3D-CRT (Three-Dimensional Conformal Radiotherapy) and HT (Helical Tomotherapy).

The current study is applied and cross-sectional. 28 patients who had nasopharyngeal cancer and were referred to Seyed al-Shohada Hospital (Omid) for treatment between 2020-2022 and are candidates for treatment with one of the 3D-CRT or HT devices; were included in this study. The treatment plan for each patient was simulated in two devices and then study variables such as maximum and average dose and homogeneity and conformity index were investigated.

Upon comparing the treatment plans of Helical Tomotherapy (HT) and Three-Dimensional Conformal Radiation Therapy (3D-CRT), it was found that the average dose received by organs at risk, such as the cochlea, was significantly lower in the HT method compared to the 3D-CRT method. This indicates a significant difference between the two treatment methods.

Our study on patients with nasopharyngeal cancer revealed that Helical Tomotherapy (HT) treatment led to better target homogeneity and compliance compared to conventional Three-Dimensional Conformal Radiation Therapy (3D-CRT). Additionally, HT was found to reduce the dose delivered to organs at risk (OARs) in comparison to 3D-CRT.