Pneumonitis in Older Lung Cancer Patients After Radiotherapy: a Scoring System for Identification of Pneumonitis in Elderly Patients Irradiated for Lung Cancer

The present prospective study investigates, whether the results of the previous prospective trial can be generalized to elderly patients aged ≥65 years. Its major goal is the identification of the optimal cut-off score to correctly diagnose pneumonitis and discriminate it from other lung diseases in elderly patients irradiated for lung cancer. In addition, the diagnostic value of an increase of the scoring points from baseline scores is evaluated. This study is a prerequisite for the development of a mobile application, which can be used by the patients at home to rate their symptoms possibly related to pneumonitis. This information will contribute to the decision whether pneumonitis is possible or likely and whether any action (e.g. consulting a pulmonologist or visiting a hospital) is required.

The main goal of this trial is to establish the performance characteristics and to develop a decision-algorithm of a new symptom-based scoring system with respect to the identification of elderly patients developing pneumonitis after radiotherapy for lung cancer. To assess the performance characteristics of the symptom-based scoring system for detection of radiation pneumonitis in elderly lung cancer patients, the receiver operating characteristic (ROC) curve is used to show the connection between sensitivity and specificity for every possible cut-off for the scoring system and to select the optimal scoring point for detection of radiation pneumonitis. The area under the ROC curve (AUC) is calculated to assess the diagnostic ability of the scoring system. Secondary aims include patient satisfaction with the symptom-based scoring system (symptom-questionnaire, paper version), assessed at the end of radiotherapy.

In case of suspected pneumonitis, patients undergo lung function tests. The suspected diagnosis of pneumonitis is considered substantiated in case of a decrease in forced expiratory volume in 1 second (FEV1) and diffusing capacity of the lung for carbon monoxide (DLCO) to less than 75% from baseline values. In this situation, patients receive a chest x-ray (which may be supplemented by a computed tomography) in accordance with the current standard procedures at the corresponding participating center. Radiation pneumonitis is considered confirmed, if opacities confined to the irradiation fields are seen on chest x-ray and/or ground-glass opacities (focal or nodular), consolidation or both are seen on computed tomography [19, 20]. If the diagnosis symptomatic radiation pneumonitis (grade ≥2) has been confirmed, patients receive medical intervention. The vast majority of the patients receive prednisolone, which is considered the mainstay of the treatment for radiation pneumonitis. If pneumonitis is not confirmed and symptoms are caused by other (e.g. underlying) disease, the patients receive treatment for this situation.

The symptom-based sum score is correlated to pneumonitis (yes vs. no). At the end of radiotherapy, patients are asked to complete a questionnaire regarding their satisfaction with the score. In case of a dissatisfaction rate >20%, the score needs modifications before it can be used in future studies. In case of a dissatisfaction rate >40%, the symptom-based scoring system will be considered not useful.

Based on samplesize calculations, 59 subjects (18 with radiation pneumonitis and 41 without radiation pneumonitis) are required within the Full Analysis Set. Assuming that 5% of subjects will not qualify for Full Analysis Set, a total of 62 subjects should be enrolled.