Rashad Ismayilov1, Anar Aliyev1, Aziz Aliyev2, Ilgar Hasanov3. 1. Department of Nuclear Medicine, Azerbaijan National Center of Oncology, Baku, Azerbaijan. 2. Department of Head and Neck Surgery, Azerbaijan National Center of Oncology, Baku, Azerbaijan. 3. Department of Pathology, Azerbaijan National Center of Oncology, Baku, Azerbaijan.