[A New Projection-Marking Technique for Breast-Conserving Surgery Using a Radiation Treatment Planning System and Multi-Leaf Collimator in Patients with Breast Cancer-A Pilot Study].

In this study, a breast-conserving surgery(BCS)was performed involving the new image projection technique, using a radiation treatment planning system(RTPS)and a multi-leaf collimator(MLC), for patients with ductal carcinoma in situ (DCIS)and invasive ductal carcinoma(IDC)with ductal components. This study aimed to evaluate the feasibility of this procedure as a pilot study. From June 2014 to May 2017, 27 patients diagnosed with DCIS and IDC with ductal components underwent BCS. In the RTPS, the design of tumor resection was simulated, and the extent of resection was projected to the breast surface using the MLC. BCS was performed using this skin marking. Among 27 patients, 4(14.8%)had carcinoma in the surgical margins. As a pilot study, the simplicity and usefulness of this procedure was confirmed in BCS for patients with DCIS and IDC with ductal components. Further evaluation of its safety and efficacy will be conducted in more patients.