Long-term regional control in the observed neck following definitive chemoradiation for node-positive oropharyngeal squamous cell cancer

Traditionally, patients treated with chemoradiotherapy for node-positive oropharyngeal squamous cell carcinoma (N+ OPSCC) have undergone a planned neck dissection (ND) after treatment. Recently, negative post-treatment positron-emission tomography (PET)/computed tomography (CT) imaging has been found to have a high negative predictive value for the presence of residual disease in the neck. Here, we present the first comprehensive analysis of a large, uniform cohort of N+ OPSCC patients achieving a PET/CT-based complete response (CR) after chemoradiotherapy, and undergoing observation, rather than ND. From 2002 to 2009, 302 patients with N+ OPSCC treated with 70 Gy intensity-modulated radiation therapy and concurrent chemotherapy underwent post-treatment clinical assessment including PET/CT. CR was defined as no evidence of disease on clinical examination and post-treatment PET/CT. ND was reserved for patients with