Stereotactic radiotherapy for early-stage non-small cell lung cancer

Abstract

Surgical resection is treatment of choice for early stage non-small cell lung cancer, even though 20%-30% of patients do not undergo surgery. Compared to conventional fractionated radiotherapy, stereotactic body radiotherapy (SBRT) has demonstrated excellent local control (LC) and overall survival (OS). Central and ultracentral lesions present higher toxicity rates after SBRT because of their proximity to mediastinal structures. Dose escalation studies have documented that 10-12 Gy per fraction is the maximal tolerable dose with acceptable rates of treatment adverse events and survival. Peripheral lesions can be safely treated with high radiotherapy dose (biologically equivalent dose of ≥ 150 Gy) and a different SBRT dose schedule has showed comparable results with LC rates > 90% and OS comparable to surgical resection. Elderly patients, defined as 75 years or older, are a subgroup of patients who may benefit the most from SBRT, as they have higher morbidity and mortality risks because of comorbidities and decreased lung function. At present, there are no randomized studies comparing SBRT with surgery for patients who are potential candidates for surgical removal. Retrospective studies and systematic reviews have showed encouraging results in terms of cancer-specific survival and LC.