A 45 years old female presented with a history of pain!less breast lump of size 6 x 5 cm in left upper quadrant with no axillary lymph nodes. A true-cut biopsy was suggestive of ductal carcinoma in situ. She undergoes surgery with resection of all tumor tissue with adequate margins and postoperative HPE showing DCIS with high grade necrosis with 4 mm clearance on margins. Which of the following is needed?