Clinical significance of radiation dose–volume parameters and functional status on the patient-reported quality of life changes after thoracic radiotherapy for lung cancer: a prospective study.

Purpose: To date, limited data exist about the relationship between radiation dose–volume parameters and patient-reported quality of life (QOL) after thoracic radiotherapy (RT) for lung cancer. We conducted this prospective study to investigate which clinico-dosimetric factors have an impact on functional declines and symptom developments after thoracic RT for lung cancer. Materials and methods: The study included 44 patients who had underwent thoracic three-dimensional conformal RT at our institution from 2016 to 2017. The health-related QOL was assessed using the EORTC QLQ-C30 and QLQ-LC13 questionnaires before RT (preRT), at the end of RT (endRT), and 3, 6, and 12 months after the completion of RT. RT dose–volume parameters of adjacent normal organs such as the lung, heart, and esophagus were retrieved and used for regression analysis. Results: Thoracic RT induced a temporary deterioration of many of the functional statuses and symptoms, but most of those improved and recovered to baseline levels 3 months after RT. However, the role function (RF) decline persisted until 6 months after RT (p < 0.05). Dysphagia showed the most noticeable change at the endRT (p < 0.001). In the multiple regression analysis, the absolute volume of body received at least 50 Gy (p = 0.021) and a preRT RF score (p = 0.001) was significantly associated with the endRT RF scores. Dysphagia at the endRT was significantly associated with the V40 of the esophagus (p = 0.047), preRT emotional function (p = 0.029), and receipt of concurrent chemotherapy (p = 0.022). Conclusions: Both the dosimetric parameters and preRT functional status have an impact on the weak aspect of patient-reported QOL, which may cause poor treatment compliance during and after thoracic RT. For patients with a low preRT QOL score or those having large tumor which may result in higher dose volumes, careful RT planning could prevent the deterioration of QOL after RT. [ABSTRACT FROM AUTHOR]