Publication:

Late dysphagia, xerostomia and submucosal fibrosis following concurrent chemoradiotherapy for locally advanced head and neck squamous cell carcinoma: a prospective comparison of intensity-modulated radiotherapy and three-dimensional conformal radiotherapy

Background Late radiation-induced toxicities remain an important cause of long-term morbidity in survivors of locally advanced head and neck squamous cell carcinoma (LA-HNSCC). Intensity-modulated radiotherapy (IMRT) offers improved dose conformity and normal tissue sparing compared with three-dimensional conformal radiotherapy (3D-CRT). This study compared late toxicity outcomes following definitive concurrent chemoradiotherapy delivered using IMRT versus 3D-CRT.

Methods This prospective observational study enrolled patients with LA-HNSCC treated with definitive concurrent chemoradiotherapy between September 2017 and December 2018. Seventy-eight evaluable patients (39 IMRT, 39 3D-CRT) were analysed. Late xerostomia, dysphagia, and submucosal fibrosis were graded at 12 months using RTOG/EORTC late radiation morbidity scoring criteria.

Results Clinically significant xerostomia (grade ≥2) occurred in 23.1% of patients treated with IMRT compared with 51.3% of those treated with 3D-CRT (p=0.019). IMRT was associated with a 55% reduction in the risk of xerostomia (RR 0.45, 95% CI 0.24-0.86). Grade ≥2 dysphagia was observed in 61.5% of patients in the IMRT group and 64.1% in the 3D-CRT group (p=1.000), while grade ≥2 submucosal fibrosis occurred in 30.8% and 43.6%, respectively (p=0.349). Patients treated with IMRT also had fewer treatment interruptions and lower rates of clinically significant weight loss.

Conclusions IMRT was associated with a significantly lower incidence of late xerostomia than 3D-CRT in patients with LA-HNSCC undergoing definitive concurrent chemoradiotherapy. Although differences in dysphagia and submucosal fibrosis were not statistically significant, the overall toxicity profile favoured IMRT. These findings support IMRT as the preferred radiotherapy technique for reducing long-term treatment-related morbidity in head and neck cancer.