(P026) Limiting 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

Christopher R. Spencer, MD, MS, Hiram A. Gay, MD, Brian Nussenbaum, MD, Douglas Adkins, MD, Tonya M. Wildes, MD, Todd A. DeWees, PhD, James S. Lewis, Jr, MD, Bruce H. Haughey, MBChB, MS, FACS, Wade L. Thorstad, MD; Washington University

Purpose: To report the results of using intensity-modulated radiation therapy (IMRT) to limit treatment of the contralateral retropharyngeal lymph nodes (RPLNs) in the clinically uninvolved neck for patients diagnosed with head and neck squamous cell carcinoma (HNSCC) in terms of safety and quality of life (QOL).

Materials and Methods: A prospective institutional database was used to identify patients treated using IMRT with primary oral cavity, oropharynx, hypopharynx, larynx, and unknown primary HNSCC between 1997 and 2010. There were three temporal treatment groups, or generations (G1–3). G1 received comprehensive neck IMRT with parotid sparing, G2 eliminated the contralateral high level II (HLII) lymph nodes, and G3 further eliminated the contralateral RPLNs in the clinically uninvolved neck. Patterns of failure and survival analyses were completed. The validated 20-question MD Anderson Dysphagia Inventory (MDADI) was used to collect patient-reported QOL data. Wilcoxon rank-sum test was used to test for significance between treatment groups.

Results: There were 748 patients identified overall: 260 in G1, 205 in G2, and 283 in G3. Of the 488 patients treated in G2 or G3, 406 had a clinically uninvolved contralateral neck and were the focus of the safety data. Median follow-up for surviving patients was 37 months. There were no failures in the spared RPLNs (95% confidence interval [CI], 0%–1.3%) or high contralateral neck (95% CI, 0%–0.7%) regions. QOL data were compared between 44 patients in G1 and 51 patients in G3. There was a significant QOL improvement globally and in all domains assessed for G3, in which reduced radiotherapy volumes were used (P < .007).

Conclusions: For patients with locally advanced HNSCC, eliminating coverage to the contralateral HLII lymph nodes and contralateral RPLNs in the clinically uninvolved side of the neck is associated with minimal risk of failure in these regions and significantly improves patient-reported QOL.