Prospective trial of Functional Lung Avoidance Radiation Therapy for Lung Cancer: Quality of Life Report

Purpose A novel form of lung function imaging has been developed that uses 4DCT data to generate lung ventilation images (4DCT-ventilation). Functional avoidance uses 4DCT-ventilation to reduce doses to functional lung with the aim of reducing pulmonary side-effects. A 4DCT-ventilation functional avoidance, phase II, multi-center clinical trial was completed. The purpose of this work is to quantify patient reported outcomes (PRO) changes for patients treated with functional avoidance and to determine which metrics are predictive of PRO changes. Materials and Methods Patients with locally advanced lung cancer receiving curative intent radiotherapy were accrued. Each patient had a 4DCT-ventilation image generated using 4DCT data and image processing. PRO instruments included the Functional Assessment of Cancer Therapy-Lung (FACT-L) questionnaire, administered pre-treatment, 3, 6, and 12 months post-treatment. FACT-TOI (Trial Outcome Index) and the FACT-LCS (Lung Cancer Subscale) percentage of clinically meaningful declines (CMD) were determined. A linear mixed-effects model was used to determine which patient, clinical, dose, and dose-function metrics were predictive of PRO decline. Results 59 patients completed baseline PRO surveys. 83% of patients had non-small-cell lung cancer, with 75% having stage III disease. The median dose was 60 Gy in 30 fractions. CMD FACT-TOI decline was 46.3%, 38.5%, and 26.8%, at 3, 6, and 12 months, respectively. CMD FACT-LCS decline was 33.3%, 33.3%, and 29.3%, at 3, 6, and 12 months, respectively. While an increase in most dose and dose-function parameters was associated with a modest decline in PROs, none of the results were significant (all p>0.053). Conclusion The current work provides an innovative combination of functional avoidance and PROs and is the first report of PROs for patients treated with prospective 4DCT-ventilation functional avoidance. Approximately 30% of patients had clinically significant decline in PROs at 12 months. The study provides additional data on outcomes with 4DCT-ventilation functional avoidance.