Would you consider radiation omission in an elderly patient with a 2 mm focus of invasive ductal carcinoma in a background of high-grade DCIS?   

I think there is a role in shared decision-making here. Based on the data we have, there is no survival difference with the addition of RT in this situation. Radiation will improve local control. When it was a choice of 5 weeks for that benefit, many chose to omit. With 5 fx, it's a different discus...