Oligometastatic squamous cell carcinoma of the head and neck treated with stereotactic body ablative radiotherapy: Single-institution outcomes

Purpose/Objectives We analyzed outcomes after stereotactic ablative body radiotherapy for oligometastatic (1-5 metastatic foci) head-and-neck squamous cell carcinoma (OM-HNSCC). Materials/Methods We reviewed patients treated between 2012 and 2016. Endpoints included overall survival (OS), distant progression, and treated-metastasis local control (TM-LC). Results We analyzed 27 patients with 60 primarily metachronous metastases (81.5%). Median follow-up was 1.6 years (0.2-5.2). Median time from diagnosis to treatment was 1.1 years (0.08-8.5). Overall, 44.4% had solitary, 44.4% had 2-3, and 11.1% had >3 metastases; most metastases were in the lung (44 of 60 metastases). Median OS was 1.9 years; at 1 and 2 years, 78% and 43% were alive (14% without disease progression). Median time to progression was 0.5 years. The 1-year and 2-year TM-LC rates were 75% and 57%. Conclusions OS is encouraging and disease-free survival remains poor; nevertheless, patients with OM-HNSCC may represent a more favorable subset of patients with metastatic HNSCC.