I am glad you have a plan. I had five treatments 20 minutes each. But a friend of mine had ten treatments ten minutes each. I had no stomach issues..just some fatigue which would just hit me so I took a nap. I arrived about 15 minutes early and they took me right on time. I was in and out in 30 minutes. At the first appointment they do marking… you lie on something that moulds to your body and they mark your body with a marker pen and cover it with special tape so that they can put you in the correct same position each time. Then the following visit is your first treatment visit. it is absolutely painless and I had to remain very still. I was able to choose music to listen to which made the time go quickly. You can drive yourself or have someone else drive you but if you bring someone they cannot be in the room with you. The radiologist doctor met me a couple of times after a treatment. He then has rescheduled me for a PET scan 2 and 1/2 months after I finished treatment to see if the tumor has broken up and how my lungs look. They have had very good success with SBRT and I think this is the “to go” procedure for elderly people who cannot have a biopsy or surgery.. I have had no side effects from the treatments except for some fatigue. They have had time will go by quickly once you start treatment. I will be thinking of you.