However, no published study has evaluated the preoperative MR imaging characteristics that can predict the surgical margin after TORS. 3, 19 Because oncologic outcomes in such cases are similar to those with chemoradiation alone, 3 it is important to preselect patients who are expected to have an insecure surgical margin to avoid unnecessary dual treatment. 2, 3, 5, 16 ⇓- 18ĭespite these advantages, there is still a risk of obtaining an insecure surgical margin (ie, positive margin involvement by the tumor or a close margin of <1 mm between the tumor and the margin) in TORS, which necessitates adjuvant therapies, even in early T1 and T2 tumors. 14, 15 While avoiding functional deficits from the traditional external approaches, TORS can reduce the need for adjuvant therapy after surgery or can use surgery as a single-technique therapy while preserving oncologic outcomes, particularly when the negative margin is achieved by TORS. 10 ⇓ ⇓– 13 Recently, transoral robotic surgery (TORS) has emerged as a first-line treatment, particularly for early-stage HPV-positive oropharyngeal SCC. 7 ⇓- 9 Long-term adverse effects from radiation or chemotherapy and high morbidity from traditional surgery through external mandibulotomy can reduce the quality of life, particularly in young patients who have to live with the consequences for far longer. The treatment protocol for HPV-positive SCC has shifted toward a “deintensification” approach to maintain favorable oncologic outcomes while minimizing treatment-related morbidity. 3 ⇓- 5 Surgery, radiation, and chemotherapy are the main treatment methods for oropharyngeal SCC and can be used alone or in combination depending on the cancer stage. 1, 2 HPV-positive oropharyngeal SCC is known for its excellent prognosis with substantially improved survival compared with HPV-negative SCC. Oropharyngeal squamous cell carcinoma (SCC) is a head and neck cancer with increasing prevalence as a consequence of rising human papillomavirus (HPV) infections. ABBREVIATIONS: AUC area under the curve cN clinical node cT clinical tumor HPV human papillomavirus pN pathologic node pT pathologic tumor ROC receiver operating characteristic SCC squamous cell carcinoma TORS transoral robotic surgery

Constrictor muscles