Five patients were simulated with using computed tomography (CT). Clinical (CTV) and planning target volumes (PTV) were created for T1N0 glottic larynx cancer. Planning risk volumes (PRV) were constructed for carotid arteries and spinal cord. Three irradiation planning, opposed lateral box field (OLBF), three dimension conformal radiation therapy (3DCRT), intensity modulated radiation therapy (IMRT) were done for each patient