Oncologic Outcomes After Robot-Assisted Neck Dissection in Oropharyngeal Carcinoma: A Subset Analysis of Severance Robot-Assisted Neck Dissection With Transoral Robotic Surgery Trial

Previously our institution has reported the surgical technique of robot-assisted neck dissection (RAND) in head and neck cancer and its surgical feasibility. We intended to examine the oncologic results in patients who underwent transoral robotic surgery (TORS) with RAND as primary therapy or as part of combined therapy for oropharyngeal squamous cell carcinoma. We reviewed a prospective robotic surgery database of 30 patients with cN0 or cN+ oropharyngeal squamous cell carcinoma treated between August 2010 and May 2013 to determine oncologic outcomes. The presenting tumor stage, histopathologic factors and adjuvant treatment extent were evaluated. Oncologic outcomes included local, regional, and distant control and overall survival and disease-free survival. There were 24 males and 6 females and the average age was 55.1 years. All patients received TORS with RAND and contralateral RAND was conducted in 3 patients, so 33 RANDs were performed in total. Selective neck dissection (SND) of levels II to V was the most common type of RAND (n=21), followed by SND (II,III) (n=5), modified radical neck dissection (MRND) (I to V) (n=3), SND (II, III, IV) (n=2) and SND (I,II, III) (n=2). Free flap reconstruction was performed in 7 patients, all of which the procedure was conducted successfully through the retroauricular port. The pathology was squamous cell carcinoma in all patients and the most common subsite was the tonsil (n=24). The primary subsites in the remaining patients were base of tongue (n=5) and soft palate (n=1). The pathologic T and N classification of the patients were as follows: T1 10 patients, T2 17 patients, T3 3 patients, N0 6 patients, N1 9 patients, N2b 13 patients, N2c 2 patients. The average number of lymph nodes retrieved was 34.6 and the average number of positive nodes was 2.5. In terms of adjuvant treatment, 16 patients received concurrent chemoradiation therapy and 8 received radiation therapy. The average follow up period was 11.3 months (range 0-36 months). Among the 30 patients, two died of conditions unrelated to the disease. During the follow up period, there was no incidence of nodal recurrence. Three-year estimated local control and regional control were 100% and 100%, respectively. The 3-year overall survival rate and disease free survival rate was 93.2% and 100% respectively. TORS with RAND achieves acceptable oncologic outcomes with appropriate adjuvant therapy in oropharyngeal carcinoma. RAND could be considered as a valid treatment of the neck in selected patients with oropharyngeal carcinoma.