High Superior-Middle Pharyngeal Constrictor Muscle Mean Dose Correlates with Severe Late Lung Infection and Survival in Nasopharyngeal Cancer Patients

Wen-Shan Liu; Ju-Chun Chien; Yu-Hsien Huang; Po-Chun Chen; Wei-Lun Huang; Shao-Wei Chiang; Ching-Chih Lee; Bor-Hwang Kang; Yu-Chang Hu

doi:10.2147/CMAR.S350714

High Superior-Middle Pharyngeal Constrictor Muscle Mean Dose Correlates with Severe Late Lung Infection and Survival in Nasopharyngeal Cancer Patients

Cancer Manag Res. 2022 Mar 8:14:1063-1073. doi: 10.2147/CMAR.S350714. eCollection 2022.

Authors

Wen-Shan Liu^{1

2

3}, Ju-Chun Chien¹, Yu-Hsien Huang¹, Po-Chun Chen^{4

5}, Wei-Lun Huang¹, Shao-Wei Chiang¹, Ching-Chih Lee⁶, Bor-Hwang Kang^{3

6}, Yu-Chang Hu¹

Affiliations

¹ Department of Radiation Oncology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
² Department of Nursing, Meiho University, Pingtung, Taiwan.
³ School of Medicine, National Defense Medical Center, Taipei, Taiwan.
⁴ Department of Radiation Oncology, Pingtung Christian Hospital, Pingtung, Taiwan.
⁵ Graduate Institute of Bioresources, National Pingtung University of Science and Technology, Pingtung, Taiwan.
⁶ Department of Otorhinolaryngology - Head and Neck Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.

Abstract

Purpose: The study aimed to evaluate 1) the correlation of doses of swallowing-related organs at risk (OAR) with severe swallowing-related late adverse effects (AE) in nasopharyngeal carcinoma (NPC) patients and 2) the effect of high mean doses of OARs on overall survival (OS).

Patients and methods: This retrospective cohort study enrolled non-metastatic Stage I-IV NPC patients from January 2012 to June 2017. OAR mean doses and severe (≥G3) swallowing-related late AE (xerostomia, dysphagia, and lung infection) were evaluated by t-test and validated using receiver operating characteristic curves. The risk factors of OS were calculated by Cox regression methods.

Results: This study enrolled 185 (43 female, 142 male) NPC patients, mean age 52.4 years, primarily with Stage III (93, 50.3%) or Stage IV (67, 36.2%) disease. The mean doses of pharyngeal constrictor muscle (PCM), superior-middle PCM (SMPCM), and superior PCM (SPCM) were significantly higher in those with severe (≥G3) lung infection than in those without (65.7 vs 62.2 Gy, p = 0.036; 68.1 vs 64.2 Gy, p = 0.015; and 70.0 vs 65.9 Gy, p = 0.012, respectively). Patients with severe (≥G3) dysphagia had significant higher mean doses of base of tongue (56.2 vs 50.2 Gy, p = 0.008), laryngeal box (50.6 vs 46.4 Gy, p = 0.036), PCM (65.4 vs 62.1 Gy, p = 0.008), SMPCM (67.1 vs 64.2 Gy, p = 0.014), and SPCM (69.3 vs 65.8 Gy, p = 0.004). Mean SMPCM dose >64.9 Gy (adjusted hazard ratio [aHR] = 3.2, 95% confidence interval [CI] 1.2-8.8, p = 0.021), age >62 years (aHR = 2.7, 95% CI 1.1-6.9, p = 0.032), N3 status (aHR = 4.0, 95% CI 1.8-9.0, p = 001), and severe late AE of lung infection (aHR = 4.6, 95% CI 1.5-14.0, p = 0.007) significantly affected OS.

Conclusion: Severe lung infection and dysphagia were associated with significantly higher mean doses of PCM, SMPCM, and SPCM. Among these OARs, only a high SMPCM mean dose was a risk factor for OS in NPC patients.

Keywords: dysphagia; intensity-modulated radiotherapy; late adverse effect; nasopharyngeal carcinoma; pharyngeal constrictor muscle; pneumonia.