High Median Dose Of Pharyngeal Constrictor Muscle Correlated With Severe Late Dysphagia And Pneumonia In Nasopharyngeal Cancer Patients

Abstract

To evaluate the correlation of pharyngeal constrictor muscle (PCM) dosage and severe late dysphagia or pneumonia in nasopharyngeal carcinoma (NPC) patients. To evaluate the risk factors of overall survival (OS). This retrospective cohort study enrolled non-metastatic stage I to IV NPC patients from January 2012 to June 2017. The structures of PCM and laryngeal doses were retrospective delineated and calculated. Severe (> = G3) late adverse effects (AE) of dysphagia and lung infection were defined by CTCAE 4th edition criteria. The significant correlations between above two structures and severe late AE were evaluated by student t-test. The risk factors of estimated 5-years OS rates were calculated by Kaplan-Meier and Cox regression methods. These factors included gender, age groups, T-Stage, N-stage, Stage, RT time, pneumonia and severe dysphagia etc. There were 185 patients enrolled in this study. There were 43 female and 142 male NPC patients with the median age of 52.0 years-old (mean 52.4 y/o ± 13.7 years). The majority of stage groups were stage III and IV, 93 and 67 cases, respectively. The median doses of PCM and laryngeal box were 62.8 Gy and 46.4 Gy, respectively. Higher PCM doses were significantly correlated with severe lung infection (62.9 Gy vs. 68.0 Gy, p = 0.008) and severe dysphagia (62.7 Gy vs. 66.6 Gy, p = 0.008). The laryngeal doses were not significantly correlated with severe lung infection (46.5 Gy vs. 47.3 Gy, p = 0.767) nor dysphagia (46.2 Gy vs. 49.8 Gy, p = 0.093). Risk factors of N3 status (p = 001), Stage (I∼IV, p = 017), longer RT time (>55 days, p = 0.007), severe lung infection (p = 0.000) and severe dysphagia (p = 0.000) significantly correlated with 5-years OS by uni-variate analysis. The N3-Stage (OR = 5.6, p = 0.018) and severe lung infection (OR = 4.2, p = 0.041) were the independent risk factors of OS. High PCM median dose correlated with severe late AE of dysphagia and lung infection significantly. Advanced N3 Stage and severe lung infection were the independent risk factors of OS.