Concomitant Radiation and Cisplatin With and Without Tirapazamine in Treatment of Advanced Head and Neck Cancer

Inclusion Criteria: * Previously untreated squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx. * Stage III or IV disease (excluding T1N1, and T2N1). * ECOG performance status less than or equal to 2. * Absolute neutrophil count at least 1.5 X 10\^9/L, platelet count at least 100 X 10\^9/L, and hemoglobin \> 9g/dL. * Serum bilirubin \< 1.25 times ULN and AST/ALT \< 2.5 times ULN. * Calculated creatinine clearance (Cockcroft-Gault) \> 55 mL/min. Exclusion Criteria: * Metastatic Disease