Second primary lung cancer (SPLC) occurs at a rate of 1-2% per year in nonsmall cell lung cancer (NSCLC) patients following surgical resection. Wang and colleagues examined patterns of second primary lung cancer in patients undergoing CT scans at fixed 6-month intervals during the first 2 years. All patients in their study but one had the second primary lung cancer identified at the asymptomatic stage (Y. Wang et. al). It is critical to detect SPLC when asymptomatic as presence of symptoms at diagnosis is associated with detection at later stage and worse overall survival (L. Calman et. al)( F. Lou et. al). With increasing implementation of stereotactic ablative radiotherapy (SABR) for medically inoperable, early stage NSCLC, improved understanding of SPLC in this population is important.