This is a longitudinal assessment of QoL on 287 NPC patients treated with IMPT (n=41) and VMAT (n=246). Both groups exhibited improved scores of global QoL, functional QoL, and C30 symptoms at 12 months post RT compared to the pre-RT status. However, during radiotherapy treatment period, there were significant difference on functional QoL (p = 0.040) and HN35 symptoms (p = 0.004), which IMPT created an average of 7.5 points higher functional QoL and 10.7 points lower HN35 symptoms than VMAT. IMPT demonstrated superior mean dose reductions in 12 of the 16 OARs compared to VMAT, including a significant (>50%) reduction in the oral cavity and larynx. The authors concluded that compared to VMAT, dose reduction attributed to IMPT could translate into better functional QoL and HN35 symptoms, but the effect is time dependent and exclusively observed during the RT phase.