Reduced Volume of Neck Prophylactic Irradiation in Nasopharyngeal Carcinoma

All target volumes will be outlined slice by slice on the axial contrast-enhanced CT with MR fusion images in the treatment planning system. The target volumes are defined in accordance with the International Commission on Radiation Units and Measurements Reports 83. The prescribed dose is 70-72 Gy to PTVp (Planning target volume of the primary tumor), 64-70 Gy to PTVn (Planning target volume of the lymph node),60- 64Gy to PTV1 (High-risk planning target volume), and 54-58 Gy to PTV2 (Low-risk planning target volume) in 30-32 fractions. The details of dose limits for organs at risk are based on the study 0225 from The Radiation Therapy Oncology Group (RTOG 0225).

Chemotherapy will be arranged by the physician-in-charge according to the NCCN guideline, patient's stage and physical condition.