Multinational phase 3 study of radiation doses and fractionation scedules in non-low-risk DCIS in the breast

Whole breast irradiation (WBI) after breast conserving surgery for ductal carcinoma in situ (DCIS) reduces local recurrence. The multinational phase 3 BIG 3-07/TROG 07.01 study (1608 patients of 136 centers in 11 countries) found that tumor bed boost (16 Gy in eight fractions) after conventional or hypofractionated WBI in patients with resected non-low-risk DCIS was associated with reduced local recurrence at the cost of an increase in grade 2 or greater toxicity