Parotid area lymph node metastases from preliminarily diagnosed patients with nasopharyngeal carcinoma: report on tumor characteristics and oncologic outcomes

// Yuanji Xu 1,* , Mingwei Zhang 1,* , Youping Xiao 1,2 , Jingfeng Zong 3,4 , Sufang Qiu 1,3,4 , Penggang Bai 3,4 , Yitao Dai 3,4 , Lin Zhou 1 , Xiaolin Chen 1 , Wei Zheng 3,4 , Yunbin Chen 1,2 , Shaojun Lin 3,4 and Jianji Pan 1,3,4 1 The Shengli Clinical Medical College of Fujian Medical University, Fuzhou, China 2 Department of Radiology, Teaching Hospital of Fujian Medical University, Fujian Provincial Cancer Hospital, Fuzhou, China 3 Department of Radiation Oncology, Teaching Hospital of Fujian Medical University, Fujian Provincial Cancer Hospital, Fuzhou, China 4 Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, China * These authors have contributed equally to this work Correspondence to: Jianji Pan, email: // Shaojun Lin, email: // Keywords : nasopharyngeal carcinoma, parotid area lymph node metastases, tumor characteristics, oncologic outcomes Received : October 20, 2015 Accepted : February 15, 2016 Published : February 24, 2016 Abstract The parotid area lymph node (PLN) is an uncommon site of metastasis originating from nasopharyngeal carcinoma (NPC). The study aimed to investigate clinical characteristics and outcomes of patients with preliminarily diagnosed NPC with PLN metastases. Here we retrospectively reviewed Magnetic resonance imaging (MRI) scans of 2221 patients with untreated nonmetastatic NPC who received intensity-modulated radiation therapy (IMRT). Finally, 64 (2.9%) patients were identified with PLN metastases, of which, 34 received PLN-sparing IMRT and 30 received PLN-radical IMRT. We also found that 42.2% had N3 disease and 95.3% had stages III-IVb. PLN metastases on MRI were characterized by ipsilateral retropharyngeal lymph node (RLN) or level II nodal extracapsular spread (ECS), ipsilateral giant cervical nodes, ipsilateral parapharyngeal extension, or solitary parotid metastasis. The 5-year overall survival, distant metastasis-free survival, regional relapse-free survival, and parotid relapse-free survival rates were 70.4%, 64.3%, 76.7%, and 87.9%, respectively. Distant metastases were the main cause of treatment failure and death. Using PLN-sparing IMRT, sparing PLN with minimal axial diameter of