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.