Eliminating radiotherapy to the contralateral retropharyngeal and high level II lymph nodes in head and neck squamous cell carcinoma is safe and improves quality of life

BACKGROUND Radiation treatment volumes in head and neck squamous cell carcinoma (HNSCC) are controversial. The authors report the outcomes, patterns of failure, and quality of life (QOL) of patients who received treatment for HNSCC using intensity‐modulated radiation therapy (IMRT) that eliminated the treatment of contralateral retropharyngeal lymph nodes (RPLNs) in the clinically uninvolved neck. METHODS A prospective institutional database was used to identify patients who had primary oral cavity, oropharyngeal, hypopharyngeal, laryngeal, and unknown primary HNSCC for which they received IMRT. There were 3 temporal groups (generations 1‐3). Generation 1 received comprehensive neck IMRT with parotid sparing, generation 2 eliminated the contralateral high level II (HLII) lymph nodes, and generation 3 further eliminated the contralateral RPLNs in the clinically uninvolved neck. Patterns of failure and survival analyses were completed, and QOL data measured using the MD Anderson Dysphagia Inventory were compared in a subset of patients from generations 1 and 3. RESULTS In total, 748 patients were identified. Of the 488 patients who received treatment in generation 2 or 3, 406 had a clinically uninvolved contralateral neck. There were no failures in the spared RPLNs (95% confidence interval, 0%‐1.3%) or in the high contralateral neck (95% confidence interval, 0%‐0.7%). QOL data were compared between 44 patients in generation 1 and 51 patients in generation 3. QOL improved both globally and in all domains assessed for generation 3, in which reduced radiotherapy volumes were used (P