Background <p>Non-palpable breast cancer lesions can be treated with breast-conserving surgery, for which precise localization of lesions is key. Many localization techniques are available, but all have limitations. The European Institute of Oncology designed the RADIOSO Milan Trial to evaluate the clinical impact of SCOUT^® radar localization (Merit Medical&#xa0;Systems Inc.), a wire-free, non-radioactive, non-magnetic technology for precise localization of non-palpable breast lesions.</p> Methods <p>RADIOSO was a single-center, prospective, observational study that enrolled patients with histologically confirmed non-palpable breast lesions eligible for breast-conserving surgery. Respective surveys were used to evaluate patient, radiologist, and surgeon satisfaction with the clinical impact of SCOUT^®.</p> Results <p>A total of 298 patients were enrolled after giving informed consent; 254 were included in the final study analysis. The reflector was placed and removed successfully in all cases. In 16% of cases, the reflector was placed during the biopsy, improving patient workflow. In total, 98% of radiologists, 89.8% of surgeons, and 91.8% of patients declared themselves satisfied with the use of SCOUT^®. No significant SCOUT^®-related artifacts were observed, regardless of the radiological modality chosen.</p> Conclusions <p>SCOUT^® is a promising preoperative localization device for non-palpable breast and axillary lesions. It facilitates a single-step placement approach by enabling the concurrent deployment of the radar reflector during the initial biopsy, optimizing clinical workflow.</p> <p><i>Clinical Trial Registration</i>: NCT05963464.</p>