Patients with locally advanced head and neck cancer will be treated with weekly carboplatin, paclitaxel, and concurrent radiotherapy. Radiotherapy will be delivered at 1.8 Gy every day, to a maximum dose of 70.2 Gy. Carboplatin will be dosed at AUC=2.0, while paclitaxel will be dosed at 30mg/m2. Celecoxib will be delivered at 400mg twice daily, starting 1 week prior to the onset of radiotherapy to establish constant blood levels.