I had a lumpectomy and sentinel node biopsy almost a year ago. Negative node involvement. The cancer was small (1-5 mm )but invasive ductile. The surgeon said the margins were good. The oncologist said I didn’t need radiation. She didn’t say it as if there was any discussion. That was it. It was my left breast , so maybe there’s more concern about damage to the heart. I didn’t question it. I was just relieved. When I see her again, I’ll ask her to explain why.