Objectives: The aim of this study was to assess the safety and outcome of stereotactic body radiotherapy (SBRT) in patients with recurrent previously irradiated squamous cell carcinoma of the head and neck (rSCCHN).
Methods: We reviewed our experience with 85 patients who received SBRT for rSCCHN between January 2003 and May 2008. The mean dose of SBRT was 35 Gy (range: 15-44 Gy). The following end points were evaluated: tumor response, time-to-progression, acute and late toxicities, local control (LC) rates and impact of tumor dose and tumor size on LC, and overall survival.
Results: The median follow-up of all patients was 6 months (range: 1.3-39 months). For those patients who were alive at last follow-up (40%) the median follow-up was 17.6 months. The mean total dose of prior radiation to the primary site was 74 Gy (range: 32-170 Gy). Those patients who received SBRT <35 Gy had significantly lower LC than those with > or =35 Gy at 6 months the median follow-up time (P = 0.014). Tumor responses were 34% complete response, 34% partial response, 20% stable disease, and 12% progressive disease. Among those with an initial tumor response followed by progression (58 patients), there was a median interval of 5.5 months for time-to-progression. The 1-year and 2-year LC and overall survival rates for all patients were 51.2% and 30.7%, and 48.5% and 16.1%, respectively. Overall, the median survival for all patients was 11.5 months (range: 3-51). Treatment was well-tolerated with no grade 4 or 5 treatment-related toxicities.
Conclusions: SBRT is feasible and safe with minimal toxicities for treatment of rSCCHN patients with prior radiation therapy deemed to be poor candidates for re-irradiation by conventional means.