9mm lung nodule found lower lobe on abdomininal scan. follow up scan 6 months later nodule grew to 1.5 cm. pet scan no uptake former smoker 15 yrs ago?

Get biopsy/surgery: I know that your PET scan was negative, & that is reassuring, but I would still recommend a biopsy because of the growth of this nodule. If your nodule had not enlarged then u could follow with serial CT scans. But with this growth you have a higher risk of malignancy. You have at least a 18% chance of cancer. Go talk to a Pulmonologist. I would recommend a biopsy, which might require surgery

Needs Biopsy: Follow the treating Physician's advise. With rapid increase in 6 months; getting tisuue Dx is always very helpful. Other wise you will be worried all the time until another Imaging study is done . Excision Bx is the way to go ( removing the nodule)