@carolman210, The biopsy is important to confirm the makeup of the mass. Most lung masses are not cancerous. 1.5 cm is nothing to brush of, and your doctors will take the next steps to help determine the makeup of the mass.
The CT scan shows an image of your lungs and surrounding areas. A PET scan can be another piece of the puzzle in determining the makeup of the mass. The PET can measure how active the nodule is. Generally, cancer is very active and will have high 'uptake' of the glucose that is used during the scan, while inflammation and infection can have a lower level of uptake.
Try not to get ahead of yourself with the possible treatments. First, they'll need to confirm if the mass is cancerous. Try to focus on today and what you know today: there is something suspicious, and it needs more investigation. The diagnosis process can take a while, which is also frustrating, but it gives you time to process at each step too, so in some cases the waiting for appointments can be helpful. It's a marathon, not a sprint. Deep breath.

More on PET Scans: https://www.mayoclinic.org/tests-procedures/pet-scan/about/pac-20385078