Examining tumor control and toxicity after stereotactic body radiotherapy in locally recurrent previously irradiated head and neck cancers: Implications of treatment duration and tumor volume

Background Stereotactic body radiotherapy (SBRT) has been studied in locally recurrent previously‐irradiated head and neck cancers; however, the optimum fractionation and patient selection continues to be defined. Methods Patients ( n = 132) with locally recurrent head and neck cancer salvaged via SBRT ± cetuximab (median, 44 Gy/5 fractions) from November 2004 to May 2011 were retrospectively reviewed. Disease outcomes and toxicity were analyzed by predictive factors including treatment duration and tumor volume. Results At a median 6‐month follow‐up (range, 0–55 months), treatment duration <14 days was associated with significantly improved recurrence‐free survival (RFS) at the expense of increased late toxicity ( p = .029). Tumor volume >25 cc remained a significant predictor of inferior survival and tumor control, and was associated with significantly more acute toxicity ( p = .017) but no difference in late toxicity. Conclusion SBRT ± cetuximab achieves promising tumor control and survival with low rates of acute/late toxicity even for recurrences >25 cc. Prolongations in treatment time may decrease late toxicity at the expense of disease control. © 2014 Wiley Periodicals, Inc. Head Neck 36: 1349–1355, 2014