3D Ultrasound in the Assessment of Resection Margins During Surgery for Squamous Cell Carcinoma of the Tongue: a Comparison With Clinical Evaluation, MRI, and Histopathology

Cancer surgery is the primary treatment in the early stages of tongue squamous cell carcinoma (SCC), and the goal is the complete resection of the tumor with an adequate margin of healthy tissue around to ensure proper cancer removal. Inadequate margins lead to a high risk of local cancer recurrence and the patient will need re-surgery or adjuvant therapies. Ex-vivo imaging of the resected surgical specimen has been suggested to provide information for margin assessment and thus improve cancer surgery. In this manuscript, a protocol to investigate the clinical benefit of three-dimensional (3D) ultrasound imaging of the surgical margins and comparing the results to magnetic resonance imaging (MRI) and the clinical examination of the surgical specimen by surgeon (palpation to inspect the resected tissue) has been designed. Tumor segmentation and margin measurement (Anterior towards apex of tongue, posterior towards base of tongue, medial towards back of tongue, lateral towards floor of mouth, and profound/deep margins) will be performed by head and neck surgeons on 3D ultrasound images and by two consultant radiologists on MRI of the ex-vivo specimen. Accuracy of each method will be evaluated by computing the proportion of correctly classified margins (positive, close, and free) by each technique with respect to the gold standard histopathology.