Abstract
OBJECTIVE: In comparison to current standard photon irradiation, proton therapy (PT) significantly reduces dose to the surrounding normal tissue and therefore is expected to reduce toxicity and improve health related quality of life (HRQoL). Despite the high expectations of PT, there is very limited data on patients' HRQoL after radiotherapy. This study evaluated HRQoL in head and neck cancer (HNC) patients receiving PT and established a robust benchmark for future comparison of PT and the radiotherapy advancements. METHOD: A questionnaire-based (consisting of EORTC-QLQ-C30, EQ-5D, and EORTC-H&N-35) prospective cohort study was performed in a Dutch proton therapy center. HNC patients who received PT between January 2020 to December 2022 were enrolled in this study. The questionnaires were distributed pre-treatment, and 0, 6, 12, 24 months post-treatment. The generalized estimating equations method was used to analyze the utility change and negative impact of the radiation-related toxicities. RESULTS: 119 HNC patients were included in the study. Symptom and function scores showed the deterioration of all reported functions during the period of treatment. Most of the functions recovered within six months and improved beyond baseline. At the end of PT, the patients' utility decreased significantly (0.12 points) compared to the baseline. The loss in utility was recovered after six months and a further improvement was seen one year after the treatment. This study further provided the estimation of the disutility of each radiation related toxicity. CONCLUSION: The present study presented the impact of toxicity on patient's utility over time and further confirmed it with the results of patient-reported symptom and function. This study provided estimation of each radiation-related toxicity, including xerostomia, dysphagia, mucositis, and dermatitis, which could contribute to the value assessment through economic evaluations of PT.