4 Courses vs 2 Courses of Pembrolizumab Combined With Carboplatin and Albumin-binding Paclitaxel of Neoadjuvant Therapy in HNSCC

"Pembrolizumab,+Carboplatin+albumin-bound paclitaxel Pembrolizumab (IV), dose= 200mg , day=1 , cycle length: 21 days. Carboplatin (IV), dose=300mg/m2, day= 1, cycle length: 21 days. albumin-bound paclitaxel (IV), dose=260mg/m2, day= 1, cycle length: 21 days.~Intervention: Drug: Pembrolizumab, Carboplatin, albumin-bound paclitaxel:4 cycles"

"Pembrolizumab,+Carboplatin+albumin-bound paclitaxel Pembrolizumab (IV), dose= 200mg , day=1 , cycle length: 21 days. Carboplatin (IV), dose=300mg/m2, day= 1, cycle length: 21 days. albumin-bound paclitaxel (IV), dose=260mg/m2, day= 1, cycle length: 21 days.~Intervention: Drug: Pembrolizumab , Carboplatin, albumin-bound paclitaxel:2 cycles"