Radiation Therapy for Tracheobronchial Metastases from Head and Neck Squamous Cell Carcinoma

Tracheobronchial metastases from head and neck squamous cell carcinoma (HNSCC) represent a rare occurrence, with few reported cases in the literature. Here, we present two patients with HNSCC who developed tracheobronchial metastases at different time points in their disease course. Patient 1 presented with a localized tonsillar primary, underwent tonsillectomy and post-operative radiation therapy to the tumor bed and bilateral neck, and experienced multiple subsequent metastases in different locations throughout the tracheobronchial tree. Each time, she received surgery and/or chemoradiation therapy to the metastatic lesion(s). Patient 2 presented with a supraglottic primary metastatic to the carina and both mainstem bronchi, and, based on patient 1's recurrence pattern and a suspicion for direct tumor extension, was treated upfront with definitive chemoradiation from the supraglottis down through much of the tracheobronchial tree. A year out from treatment, patient 2 has achieved excellent locoregional control with few treatment-related toxicities but unfortunately has developed new liver metastases not seen on pre-treatment imaging. This case highlights the difficulty in ascertaining the extent of metastatic spread for HNSCC patients with isolated tracheobronchial metastases and describes our approach to delivering curative-intent radiation therapy.