Predicting outcomes from radical radiotherapy for non-small cell lung cancer: a systematic review of the existing literature.

Radical radiotherapy (RT) is a potentially curative treatment in non-small cell lung cancer(NSCLC) and is delivered in conventional 2-Gy fractions, hypofractionated and ablativestereotactic courses. No reliable, predictive biomarkers for the clinical events of local control,appearance of distant metastases and development of toxicity have been introduced in routineclinical practice. Such a test would enable the Radiotherapist to tailor the clinical management ofindividual patients, considering their pre-treatment characteristics, in order reduce the risk ofrecurrence or toxicity eg dose modification, accelerated fractionation, hypofractionation, orconcurrent systemic therapy. The aim of this review was to map the published literature relatingto investigations of the potential predictive value of patient or treatment characteristics in radicalRT for NSCLC. These investigations should remain a research focus for disease control given theupward trends in lung cancer incidence, and for the avoidance of toxicity, given the survivorshipafforded to the cohort of patients that do well with radical RT, or with the increasing range ofsystemic agents following metastatic relapse. The conclusion of the presented analysis is that thereare no published, effective and validated predictive tools for estimation of risk of local/distantrecurrence or toxicity after radical RT for NSCLC. The authors have identified an important spacefor future research in the field of lung cancer radiotherapy.