A Prospective Non-interventional Multicenter Cohort Study to Evaluate Different Imaging-guided Methods for Localization of Non-palpable Malignant Breast Lesions

In the last decades, the proportion of breast cancer (BC) patients receiving breast-conserving surgery has increased steadily, reaching 70-80% in developed countries. Since positive resection margins are strongly associated with local recurrence risk, the goal of breast surgery is the complete tumor removal and most national and international guidelines recommend re-operation, either in form of re-excision or mastectomy, until clear margins have been reached. Re-operation rates vary widely, with population-based studies reporting a range of 15-35%, and the necessity for a second surgery can lead to increased patient anxiety, a delay in start of adjuvant treatment, worse cosmetic outcome and increased complication rates and costs. Therefore, re-operation rate has been included as a quality indicator in several countries.

Several imaging-guided techniques have been developed to guide removal of non-palpable breast lesions, the oldest one being preoperative wire placement under ultrasound or mammographic guidance, usually followed by radiography or ultrasound of removed tissue. Newer techniques, such as intraoperative ultrasound (IOUS), radioguided occult lesion localization (ROLL), radioactive seed localization (RSL), radar reflector-localization (RRL), magnetic seed localization (MSL), and radiofrequency identification (RFID) tags have been introduced as an alternative to wire-guided localization (WGL).

To date, comparative data on the rates of successful lesion removal, negative margins, re-operation rate and patient's comfort depending on the localization technique used are limited. Further, since some of these studies were funded by the manufacturer of the marker examined, a potential bias cannot be excluded. In the vast majority of the available studies, the patient's perspective with regard to discomfort and pain level has not been evaluated.

The aim of the proposed study is to comparatively evaluate different imaging-guided localization methods used for surgical removal of malignant breast lesions with regard to oncological safety and patient-reported outcomes.