Second infield re‐irradiation with a resulting cumulative equivalent dose (EQD2 max ) of >180 Gy for patients with recurrent head and neck cancer

Background For locally recurrent head and neck cancer, re-irradiation with modern techniques like stereotactic body radiotherapy is a promising, possibly curative alternative to palliative systemic therapy. Methods We report on 1 patient with nasopharyngeal carcinoma (NPC) and 1 patient with cutaneous squamous cell carcinoma (SCC). Both patients received full dose primary treatment (>66 Gy, EQD2), full dose re-irradiation (>50 Gy, EQD2), and a second course of re-irradiation via robotic radiosurgery (CyberKnife) for a second local recurrence. Results Both treatments resulted in adequate tumor response. No grade III-IV acute or late toxicities occurred. Follow-up at 6 months after third irradiation showed partial remission for the patient with NPC. In the second case (SCC), no toxicities occurred and the tumor was in remission 18 months after last treatment. Conclusion These cases show that a second course of re-irradiation utilizing modern techniques like robotic radiosurgery might be feasible for carefully selected patients with head and neck cancer.