Individualized Elective Neck Irradiation in NPC Patients

Inclusion Criteria: * The eligibility criteria are: newly diagnosed, untreated, non-distant metastatic, and non-keratinizing NPC; nodes are diagnosed with PET/CT and MRI; staged as T1-4N0-2 or N3 category of non-bilateral lower-neck node metastasis; aged between 18 and 70 years; Karnofsky performance-status score \> 70; adequate haematological function, with a leucocyte count \> 4 × 109/L, haemoglobin \> 90 g/L, and a thrombocyte count \> 100×109/L Exclusion Criteria: * The exclusion criteria include: previous chemotherapy treatment, surgery (except diagnostic) or radiotherapy to the neck or nasopharyngeal regions; previous malignancy; lactation or pregnancy; or severe coexisting illness.