Not to comment on your situation specifically, just some interesting related information: The national lung screening trial [1] which had on the order of ~25k

Not to comment on your situation specifically, just some interesting related information: The national lung screening trial [1] which had on the order of ~25k CT scan patients and ~25k radiograph patients found 96.4% and 94.5% of the positive screenings to be false positives. This screening trial has been a large motivator for computer-aided detection, diagnosis, and characterization of lung CT scans (although work on this goes back to the 80s and 90s). If you look at the fleischner guidelines [2], the key factors in determining follow up are patient background and nodule size and growth rate. There are secondary diagnostic characteristics that are correlated with malignancy as well, e.g. spiculation and texture patterns. [1]: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4356534/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4356534/ [2]: http://radiopaedia.org/articles/fleischner-society-pulmonary-nodule-recommendations http://radiopaedia.org/articles/fleischner-society-pulmonary...