Would you assume a diagnosis of metastatic recurrence and initiate therapy for a patient with history of locally advanced NSCLC treated with definitive chemoradiation who develops multiple enlarging lung nodules that are too small to biopsy?  

I don't believe that I can point to a study that will answer this question, so will revert to oncologic principles 101, namely that absent exceptional circumstances, we ought to biopsy first recurrence.  In the question posed, that is following definitive (curative intent) chemoradiation (and n...