Through multicenter, open-label, randomised clinical trials, patients with NPC staged as II-III with CR/PR according to RECIST criteria and EBV DNA decreased to 0 copies/mL after 3 cycles of GP induction chemotherapy will be randomized into experimental group to receive IMRT of reduced dose (prescribed dose, 63.6 Gy, 2.12 Gy per fractions, 30 fractions) and control group to receive IMRT of conventional dose (prescribed dose, 69.96 Gy, 2.13 Gy per time, 33 fractions). Two cycles of cisplatin chemotherapy will be performed during IMRT. The efficacy, toxicity, and quality of life of patients between the two groups will be compared.
Through multicenter, open-label, randomised clinical trials, we intend to demonstrate that radiotherapy with reduced dose could significantly reduce the incidence of radiotherapy toxicities, improve the quality of life of patients while ensuring the tumor control rates for NPC patients staged as II-III who are sensitive to induction chemotherapy (imaging evaluation of CR/PR and EBV DNA copy number decreased to 0 copies/mL after induction chemotherapy)