HI Charlene, My husband had surgery on liver last January, but then had RFA on a lung spot four months ago. He stayed overnight in hospital though some people go home same day. Tom had a blood pressure slight problem (I can't remember if it was high or low) most likely from anesthesia so that's why he stayed the night.
The procedure he tolerated easily, nothing like surgery. The radiologist sticks in one thin needle and the procedure is watched on screen. when the needle hits the target area, then the dr. pushes through the skinny needle some even skinnier probes that fan out and ablate, or destroy, the target tissue. This is done with radio waves...the effect is "cooking" the area. Then this spot gets inflamed. The first month scan, the dr said the spot always looks bigger rather than smaller...so don't be surprised or worried. The surrounding tissue gets inflamed and the tumor tissue will die off. So far my husband has had two follow up scans. The area looks smaller. They monitor for 6 - 9 months. If the spot doesn't disappear, he has the choice of repeating the ablation or having a surgical excision and biopsy.
Overall it is a relatively painess procedure compared to surgery. There is stress on the body...but minimalized as much as possible.
I found more info on RFA by searching for "Interventional Radiology."
Hope this helps.