Biomechanical modeling of neck flexion for deformable alignment of the salivary glands in head and neck cancer images.

Biomechanical modeling of neck flexion for deformable alignment of the salivary glands in head and neck cancer images. Phys Med Biol. 2019 Jul 03;: Authors: McCulloch M, Anderson BM, Cazoulat G, Peterson CB, Mohamed ASR, Volpe S, Elhalawani HM, Bahig H, Rigaud B, King J, Ford A, Fuller CD, Brock KK Abstract During head and neck (HN) cancer radiation therapy (RT), dose-response analysis for the parotid glands (PG) relies on accurate alignment of soft tissue between longitudinal images. To isolate the response of the PG to delivered dose, from deformation due to patient position, patient postural changes, mainly due to neck flexion, should be resolved. A biomechanical model-based deformable image registration (DIR) algorithm was evaluated to estimate the displacements and deformations of the PGs due to postural changes. Eighty-two CT image pairs of HN cancer patients with varying neck flexion angles were obtained. CT pairs of each patient were aligned using bone-based rigid registration. Images were deformed using biomechanical model-based DIR focused on mandible, C1, C3, and external contour. For comparison, intensity-based DIR was also performed.
 Accuracy of the biomechanical model-based DIR was assessed using Dice similarity coefficient (DSC) for all images and for the subset of images with PG volume change <20%. Accuracy was compared to intensity-based DIR.
 The PG mean±STD DSC were 0.63±0.18, ...
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research