Impact of head and neck radiotherapy for patients with nasopharyngeal carcinoma on sleep-related breathing disorders

IMPORTANCE: Little is known about the relationships between sleep-related breathing disorders (SRBDs) and nasopharyngeal carcinoma (NPC). OBJECTIVE: To clarify the impact of head and neck radiotherapy on SRBDs, we performed a pilot study to investigate the change of sleep architecture in patients with NPC before and after treatment. DESIGN, SETTING, AND PARTICIPANTS: A retrospective review of a prospective data set of 18 patients with NPC (15 men and 3 women; mean age, 49.8 years) and symptoms of SRBD, who completed radiotherapy and underwent polysomnography before and after treatment at a university-affiliated tertiary referral center. INTERVENTIONS: Radiotherapy and/or chemotherapy were applied based on the NPC stage. MAIN OUTCOMES AND MEASURES: Subjective SRBD symptoms, Epworth sleepiness scale score, snoring severity (visual analog scale, rated 0-10 by bed partner), and objective full-night polysomnographic parameters (apnea-hypopnea index [AHI], AHI in rapid eye movement [REM] sleep, central sleep apnea index, percentage of light sleep, percentage of deep sleep, percentage of REM sleep, sleep efficiency, sleep latency, arousal index, mean oxygen saturation, lowest oxygen saturation, desaturation index, and snoring index) were collected before and at least 6 months after treatment. RESULTS After treatment, Epworth sleepiness scale and snoring severity scores significantly decreased from a mean (SD) of 11.0 (5.0) to 7.8 (2.3) (P = .005) and 6.0 (3.4) to 2.8 (2.3) (P < .001), respectively. The AHI changed from 26.2 (28.4) to 21.67 (24.15) (P = .28). However, AHI increased in 8 of 18 patients. A statistically significant increase was shown in mean oxygen saturation, from 95.3%(2.0%) to 97.1%(1.4%) (P < .001), though lowest oxygen saturation was not significantly altered. Percentage of light sleep increased significantly from 78.9%(8.8%) to 86.1%(9.6%) (P = .02), and percentage of REM sleep decreased from 17.5%(6.4%) to 12.7%(8.9%) (P = .10). Percentage of deep sleep was not significantly altered. CONCLUSIONS AND RELEVANCE: Although the severity of apnea and hypopnea events and snoring decreased in most of the patients with NPC after treatment, the sleep architecture became disrupted and 8 of 18 of the patients had an increased AHI after treatment. Identification and treatment of obstructive sleep apnea and hypopnea in patients with NPC may be important factors for improving the quality of life.