Comparison of Preoperative DOI Estimation in Oral Tongue Cancer With cN0 Disease.

OBJECTIVE: To understand the accuracy of pre- and intraoperative estimation of tumor depth of invasion (DOI). STUDY DESIGN: A retrospective case-control study. SETTING: Patients who presented at 1 institution with oral tongue squamous cell carcinoma that underwent oncologic resection between 2017 and 2019 were identified. METHODS: Patients that met the inclusion criteria were included. Patients with nodal, distant, or recurrent disease, prior history of head and neck cancer, or preoperative tumor assessment and/or final histopathology that did not include DOI were excluded. Preoperative DOI estimation and technique and pathology reports were obtained. Our primary outcome was the sensitivity and specificity of DOI estimation modalities including full-thickness biopsy (FTB), manual palpation (MP), punch biopsy (PB), and intraoperative ultrasound (IOUS). RESULTS: Tumor DOI was assessed quantitatively preoperatively in 40 patients by FTB (n = 19, 48%), MP (n = 17, 42%), or PB (n = 4, 10%). Additionally, 19 patients underwent IOUS to assess DOI. The sensitivities of FTB, MP, and IOUS for DOI ≥ 4 mm were 83% (confidence interval [CI]: 44%-97%), 83% (CI: 55%-95%), and 90% (CI: 60%-98%), respectively, and the specificities were 85% (CI: 58%-96%), 60% (CI: 23%-88%), and 78% (CI: 45%-94%). CONCLUSION: Our study demonstrated that DOI assessment tools measured had similar sensitivity and specificity in stratifying patients with DOI ≥4 mm, with no statistically superior diagnostic test. Our results support the need for additional research into nodal disease prediction and continued refinement of ND decisions with respect to DOI.