Submandibular Gland-Sparing Technique Versus En-Bloc Level IB Dissection in Oral Cavity Cancers with N0 Neck Status: A Randomized Controlled Trial

IMPORTANCE: Metastases to the submandibular gland (SMG) from oral cavity primaries are very rare. Hence, a gland-preserving level IB dissection technique is a feasible option without compromising the lymph node yield (LNY). OBJECTIVE: To assess the feasibility and noninferiority of the SMG-preserving dissection technique to the conventional en bloc removal of level IB in terms of LNY in patients with cN0 oral squamous cell carcinoma (OSCC) undergoing elective neck dissection. DESIGN: Parallel-design, single-center, open-label, randomized controlled trial. SETTING: Tertiary care health care center-Department of Otorhinolaryngology-Head & Neck Surgery, AIIMS Rishikesh. PARTICIPANTS: Thirty-eight (n = 38) participants with 46 (n = 46) neck dissection specimens of OSCC were randomly allocated (1:1) into gland-preserving (n1 = 23) and en bloc (n2 = 23) dissection groups. INTERVENTION: Elective neck dissection comparing SMG-sparing level IB dissection technique versus en bloc level IB dissection. MAIN OUTCOME MEASURES: LNY, lymph node density, and level IB operative time in both groups were compared between groups (α < .05). RESULTS: Median LNY (P = .543) and lymph node density (P = 1.000) in level IB did not show significant differences between the groups. LNY in level IB by gland-preserving technique is also not inferior to the conventional en bloc dissection technique (mean difference = 0.217; 95% CI: [-0.597, 1.032]; P = .593). The mean level IB operative time is significantly longer in the gland-preserving group (P < .001). CONCLUSIONS AND RELEVANCE: None of the examined SMGs were involved by the tumor. SMG-preserving technique is noninferior to the traditional technique of level IB clearance and can be used in elective neck dissections without compromising the LNY. Functional neck dissection has greatly evolved to decrease patient morbidity, and this method can be adopted in case-specific situations. TRIAL REGISTRATION: The trial was registered in the Clinical Trials Registry-India (CTRI/2022/05/042344) on May 2, 2023, https://ctri.nic.in/.