TPC vs PF as Induction Chemotherapy Combined With CCRT for Stage IVa-b Nasopharyngeal Carcinoma

Inclusion Criteria: * WHO II or III pathological type * stage Ⅳa or Ⅳb (UICC 7th edition) * no anticancer treatment before * no malignant history * both gender, 18-60 years old * enough liver function: TBIL≤ULN；AST/ALT≤2.5×ULN；ALP≤5×ULN * enough kidney function: Clcr≥80 mL/min * enough hemo: ANC≥2×109/L, PLT≥100×109/L and HB≥9g/dL * no sever heart, lung disfunction * PS≤2 Exclusion Criteria: * previous anticancer treatment * distant metastasis * pregnant or breasting female * can not access to followup * enrolled in other therapeutic clinical trial * sever infection and internal disease * sever disfunction of heart, lung, kidney, liver, etc * TBIL\>ULN；AST/ALT\>2.5×ULN；ALP\>5×ULN * with factors that will affect the administration, distribution,metabolism or evacuation. * using immunosuppressive agents after organ transplantation * other malignant history