Late toxicities in locally advanced head and neck squamous cell carcinoma treated with intensity modulated radiation therapy.

Purpose: The study aims to report late toxicities in locally advanced head-and-neck squamous cell carcinoma (LAHNSCC) treated with intensity-modulated radiation therapy (IMRT).

Materials and methods: A retrospective study was conducted on 103 patients of LAHNSCC treated with IMRT. We analyzed the cumulative incidence of late xerostomia, dysphagia, and aspiration at an interval of 6-month, 1-year, 2-year, and 3-year from the start of IMRT.

Results: At a median follow up of 4.2 years (interquartile range, 3.5 to 6 years), the cumulative incidence of grade ≥2 late xerostomia was 5.5%, dysphagia was 6.9%, and aspiration was 11.1%. Logistic regression showed that Dmean of ≥26 Gy to parotids had higher risk of xerostomia (hazard ratio [HR] = 5.19; 95% confidence interval [CI], 1.90-14.22; p = 0.001). Late dysphagia was associated with Dmean of ≥45 Gy to pharyngeal constrictors (PC) (HR = 7; 95% CI, 1.84-26.61; p =0.004), ≥55 Gy to larynx (HR = 3.25; 95% CI, 1.15-9.11; p = 0.025), and adjuvant RT (HR = 5.26; 95% CI, 1.85-14.87; p = 0.002). Aspiration was associated with Dmean of ≥45 Gy to larynx (HR = 6.5; 95% CI, 1.93-21.88; p = 0.003), Dmean of ≥55 Gy to PC (HR = 3.54; 95% CI, 1.25-9.98; p = 0.017), and patients having late dysphagia (HR = 4.37; 95% CI, 1.55-12.31; p = 0.005).

Conclusion: IMRT is a feasible radiation delivery technique in LAHNSCC with a decreased late toxicity profile.