How would you manage a patient with EGFR mutant adenocarcinoma of the lung on erlotinib with a single site of disease progression, but otherwise well-controlled disease?  

This is a point of controversy.  There are multiple reasonable options to consider for such a patient:   Keep going with tarceva and follow the lesion carefully.  The NCCN guidelines actually acknowledge this approach for asymptomatic disease. Use SRS or some other locally ablati...