Outcomes for oligometastatic head and neck cancer treated with stereotactic body radiotherapy: Results from an international multi-institutional consortium

BackgroundWe report the results of an international multi-institutional cohort of oligometastatic (OMD) head and neck cancer (HNC) patients treated with SBRT. MethodsPatients with OMD HNC (& LE;5 metastases) treated with SBRT between 2008 and 2016 at six institutions were included. Treated metastasis control (TMC), progression-free survival (PFS), and overall survival (OS) were analyzed by multivariable analysis (MVA). ResultsForty-two patients with 84 HNC oligometastases were analyzed. The TMC rate at 1 and 2 years were 80% and 66%, with a median time to recurrence of 10.1 months. The median PFS and OS were 4.7 and 23.3 months. MVA identified a PTV point maximum (BED)10 > 100 Gy as a predictor of improved TMC (HR = 0.31, p = 0.034), and a cumulative PTV > 48 cc as having worse PFS (HR = 2.99, p < 0.001). ConclusionFavorable TMC and OS was observed in OMD HNCs treated with SBRT.