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.
Untreated, histologically confirmed head and neck squamous cell carcinoma (oral cavity, oropharynx, hypopharynx or larynx), staging T3-4N0M0 or T1-4N1-3M0, III-IVB, according to the eighth edition of the AJCC staging system; within 6 weeks after receiving neoadjuvant therapy and radical surgery.
Pathological evaluation of surgical specimens was pCR (pathologic complete response, no viable tumor cells) or MPR (Major pathologic response, residual viable tumor cells≤10%).
Negative surgical margin.
No extranodal extension.
Pregnant or lactating women.
A history of other malignant tumors within the previous 5 years or at the time of enrollment, except for cured skin basal cell carcinoma and cervical in situ cancer, as well as thyroid papilloma.
Neoadjuvant therapy or radical surgery was not completed.
Recurrence or distant metastasis occurred before postoperative radiotherapy.