A new study entitled “Functional lung avoidance for individualized radiotherapy (FLAIR): study protocol for a randomized, double-blind clinical trial” will determine the use of functional imaging techniques, particularly the Hyperpolarized 3He MRI, in identifying functional lung areas, therefore reducing the amount of radiation received by these areas during concurrent chemo-radiotherapy in patients with non-small cell lung cancer. The study was published in the journal BMC Cancer.
Lung cancer is the leading cause of death of both men and women cancer patients worldwide, accounting for 1.6 million deaths in 2012 alone. The majority of lung cancer patients, 85 to 90%, exhibit non-small cell lung cancer (NSCLC). Currently, the standard therapeutics for locally advanced unresectable NSCLC is concurrent chemo-radiotherapy. However, with the treatment it is frequently observed an increased risk for radiation-induced lung injury (RILI) — particularly radiation pneumonitis, an often fatal condition occurring in 30 to 40% of the patients receiving concurrent chemo-radiotherapy, which is characterized by the loss of type I pneumocytes (the cells that line up the lungs alveoli and are responsible for gas exchange between the alveoli and the blood) and dyspnea. Additionally, the occurrence of radiation pneumonitis reduces the amount of radiotherapy that effectively reaches the tissue and inhibits the increase of radiotherapy dosages. Thus, due to its hazardous side-effects, there is an increasing necessity to reduce pulmonary toxicity in patients treated with concurrent chemo-radiotherapy for lung cancer.
Current radiotherapy techniques try to minimize the risk for lung toxicity by decreasing the radiation dose administered to the whole lung. However, specifically in the case of smokers, the functional areas of the lungs can be heterogeneous. Therefore, radiotherapy treatment should be administered to try to limit the amount of radiation reaching highly functional areas and direct it to the more limited- or non-functioning parts of the lung.
In this study, the authors will determine if functional lung area can be identified by a technique, Hyperpolarized 3He MRI (indicates both spatial and temporal respiratory function with high resolution) to avoid functional lung area. This study will be the first testing of the technique in a prospective randomized, double-blind clinical trial. Specifically, the trial will enroll patients with Stage III NSCLC that are scheduled to receive concurrent chemo-radiotherapy. Before administering the therapy, all patients will be screened with Hyperpolarized 3He MRI to identify the areas of the lung that are being normally ventilated. Patients will then be randomly divided and will receive two different radiotherapy plans – a group of patients will receive a standard plan (without accounting for functional lung areas) and the second group the avoidance plan (optimized to deliver the minimum radiation to functional lung areas). In total, the study will follow 64 patients during two years with primary endpoint the pulmonary quality of life (QOL) report (to be performed at 3 months after treatment); secondary endpoints include pulmonary QOL reports within other time periods, toxicity, overall and progression-free survival, as well as quality-adjusted survival.
The results obtained from this study will determine how pulmonary functional imaging allows clearance of functional lung areas of radiation, therefore improving both QOL and pulmonary toxicity in patients with unresectable NSCLC.