Challenges in the re-irradiation of locally advanced head and neck cancers: outcomes and toxicities

Purpose To retrospectively review outcomes and toxicities for patients with recurrent head and neck cancer (HNC) undergoing re-irradiation (re-RT). Methods Retrospective review of oncologic outcomes and toxicity data from patients who received head and neck (HN) re-RT with curative intent using intensity-modulated radiation therapy (IMRT) from 2011 to 2016. Common toxicities were scored using Common Terminology Criteria for Adverse Events (CTCAE) V4. Treatment outcomes included progression-free survival (PFS), locoregional control (LRC), and overall survival (OS). Results Twenty-one patients with HNC were re-irradiated with curative intent. The median follow-up after re-RT was 27.8 months. The median retreatment dose was 66 Gy (range, 60–70), and the median retreatment volume was 194.1 cm 3 (range, 52.4–1375.6). The median LRC, PFS, and OS were 10 months, 8.4 months, and 18.1 months, respectively. Patients treated with surgery as a component of primary HN cancer treatment had significantly worse PFS and OS when retreated compared with those initially treated with chemoradiation alone ( p = 0.026 and p = 0.005, respectively). Those with stage IVA/B recurrent disease had worse LRC, PFS, and OS compared with stage II/III disease ( p = 0.029, p = 0.049, and p = 0.020 respectively). Acute grade ≥ 3 toxicity and late grade ≥ 3 toxicity were 38% and 38%, respectively, with dysphagia being most common (24% acute and 14% late). Conclusion Re-irradiation with IMRT for locally advanced HN recurrences either definitively or after salvage surgery is feasible, but treatment-related toxicity remains significant. Patients who received surgery as a component of their initial treatment and those with more advanced stage disease may be more difficult to salvage with re-irradiation.