The Efficacy and Safety of De-escalated Postoperative Radiotherapy in Locally Advanced HNSCC With pCR/MPR

This is an open-label, single-arm, phase II clinical trial to explore the efficacy and safety of de-escalation of postoperative radiotherapy in locally advanced head and neck squamous cell carcinoma with pathological complete response/major pathological response to neoadjuvant therapy. The eligible patients are scheduled to administered postoperative radiotherapy, PTV 50Gy/25F, instead of the standard dose of 60Gy. The overall primary study hypothesis is that reducing the dose of postoperative radiotherapy in the specific population does not affect DFS but significantly reduces treatment related adverse events.