Quality-of-life comparison between intensity-modulated proton therapy and volumetric-modulated arc therapy in patients with nasopharyngeal carcinoma: Preliminary findings from real-world data

Background: Limited data are available to examine the effects of intensity-modulated proton therapy (IMPT) on patient-reported outcomes in patients with nasopharyngeal carcinoma (NPC). Thus, we assessed whether patients receiving IMPT reported a better short-term quality of life (QoL) than those receiving volumetric-modulated arc therapy (VMAT). Methods: We consecutively invited newly diagnosed NPC patients who had undergone standard treatment protocol within 2 years post-radiotherapy at our institute between 2021 and 2023 to participate in the observational study. All participants completed the EuroQol five-dimension, World Health Organization Quality-of-Life—Brief, Sinonasal Outcome Test 22, Eustachian Tube Dysfunction Questionnaire-7, and Eating Assessment Tool-10 (EAT-10) questionnaires. QoL functions were estimated using a kernel-smoothing method. A linear mixed model introducing the inverse probability of treatment weighting was constructed to estimate the effect of IMPT versus VMAT. Results: We identified 94 patients who completed 120 QoL assessments. Participants receiving IMPT were younger and had higher levels of education and higher household income. QoL functions showed that post-treatment EAT-10 scores consistently appeared significantly lower for IMPT than VMAT. After adjusting for factors including age, gender, education, household income, and cancer stages, patients receiving IMPT consistently showed significantly better QoL scores in EAT-10, indicative of a medium effect. Additionally, factors such as age, household income level, and treatment regimen might influence either generic or condition-specific QoL. Conclusions: Patients receiving IMPT demonstrated potentially improved eating-related QoL compared to those receiving VMAT within a 2-year post-radiotherapy period. However, larger head-to-head comparison studies are warranted to confirm these findings.