My radiation oncologist told me radiation offered a risk reduction of 55% to 60% for recurrence. Since my negative margin was only .5 mm, I went ahead with radiation and tolerated it well. I had all treatments on my back, and the technique did not affect my heart or lungs despite the tumor being quite deep. I did, however, refuse chemo. That only offered a 3% risk reduction. Totally not worth it in my book.