Alternating chemotherapy: Gemcitabine and cisplatin with concurrent radiotherapy for treatment of advanced head and neck cancer

J. L. Aguilar-Ponce, M. Granados-García, J. C. Cruz López, F. Maldonado-Magos, M. A. Alvarez-Avitia, O. Arrieta, I. González-Ramírez, G. Lara-Cruz, I. Martinez-Juárez, R. Medina-Santillan, C. Castillo-Hernández, J. De La Garza-Salazar