Researchers led by Dr. Han Shin Lee of Gyeongsang National University Hospital in Changwon, South Korea, developed 3D-printed breast surgical guides that are produced from pretreatment MRI scans and mark the original tumor area directly on the breast. In a prospective study, they found that 39 patients who had received breast conservation surgery with assistance from the 3D-printed guides had a low rate of tumor-positive resection margins and local recurrence. By using [3D-printed breast surgical guides] as a localization method in patients receiving [neoadjuvant systemic therapy], it is possible to precisely target the original tumor area observed in the pretreatment MRI, the authors wrote. In addition, the advantages of the method are that it is painless, does not include radiation, and does not increase the procedure time.