Comparison of tumor delineation using dual energy computed tomography versus magnetic resonance imaging in head and neck cancer re-irradiation cases

Abstract

In treatment planning, multiple imaging modalities can be employed to improve the accuracy of tumor delineation but this can be costly. This study aimed to compare the interobserver consistency of using dual energy computed tomography (DECT) versus magnetic resonance imaging (MRI) for delineating tumors in the head and neck cancer (HNC) re-irradiation scenario. Twenty-three patients with recurrent HNC and had planning DECT and MRI were identified. Contoured tumor volumes by seven radiation oncologists were compared. Overall, T1c MRI performed the best with median DSC of 0.58 (0-0.91) for T1c. T1c MRI provided higher interobserver agreement for skull base sites and 60 kV DECT provided higher interobserver agreement for non-skull base sites.

Keywords: Delineation; Dual energy computed tomography; Head and neck; Magnetic resonance imaging; Re-irradiation.

Fig. 1

Pairwise analysis for the cohort (A–E) and stratified by skull base versus non-skull base tumor sites (F – J): A and F) Dice similarity coefficient (DSC), B and G) volume difference, C and H) mean surface distance (MSD), D and I) Hausdorff distance (HD) and E and J) 95th percentile Hausdorff distance (95HD).

Fig. 2

Example of a skull base (A) and a non-skull base (B) cases with delineations on 60 kV, 140 kV, T1 with contrast (T1 + c) and T2 MRI sequences.