Study to Evaluate Induction Chemotherapy Using Docetaxel, Cisplatin and Fluorouracil in Concurrence With Intensity-modulated Radiotherapy for Local Recurrent Nasopharyngeal Carcinoma (NPC)

"Induction phase (Weeks 1-9):~Drug Docetaxel Docetaxel 75 mg/m2 IV, D1 every 3 weeks for 3 cycles~Drug Cisplatin Cisplatin 75 mg/m2 IV, D1 every 3 weeks for 3 cycles~Drug Fluorouracil Fluorouracil 750 mg/m2 IV, D1-4 every 3 weeks for 3 cycles~Concurrent phase (weeks 10-16):~Drug Docetaxel Docetaxel 15 mg/m2 IV, D1 weekly for 7 weeks (Weeks 10-16)~Drug Cetuximab Cetuximab 400 mg m2 IV, D1 initial dose, then 250 mg/m2 weekly for 7 week (Weeks 10-16)~IMRT (60 Gy to GTV or biological dose equivalent): 2 Gy/fraction/day, D1-5 per week, for 6 weeks (Weeks 11-16)"