I went through 6 weeks of radiation and once a week chemo without a feeding tube. I don't know the difference between a G tube and a PEG. Where I was treated they only put in a feeding tube after you lost a certain percentage of weight. It was not automatic that you would get a feeding tube before radiation treatment was started. They waited to see how you would do and if you were able to keep your weight up. I lost about 10 pounds.