Wire-guided localisation (WGL) has been the mainstay for localising non-palpable breast lesions before excision. Due to its limitations, various wireless alternatives have been developed. In this prospective study, we evaluate the role of radiation-free wireless localisation using the SAVI SCOUT^® system at the London Breast Institute. A total of 72 reflectors were deployed in 67 consecutive patients undergoing breast conserving surgery for non-palpable breast lesions. The mean interval between deployment and surgery for the therapeutic cases was 18.8 days (range: 0–210). The median deployment duration was 5 min (range: 1–15 min). The mean distance from the lesion was 1.1 mm (median distance: 0; range: 0–20 mm). The rate of surgical localisation and retrieval of the reflector was 98.6% and 100%, respectively. The median operating time was 28 min (range: 15–55 min) for the therapeutic excision of malignancy and 17 min (range: 15–24) for diagnostic excision. The incidence of reflector migration was 0%. Radial margin positivity in malignant cases was 7%. The median weight for malignant lesions was 19.6 g (range: 3.5–70 g). Radiologists and surgeons rated the system higher than WGL (93.7% and 98.6%, respectively; 60/64 and 70/71). The patient mean satisfaction score was 9.7/10 (n = 47, median = 10; range: 7–10). One instance of signal failure was reported. In patients who had breast MRI after the deployment of the reflector, the MRI void signal was <5 mm (n = 6). There was no specific technique-related surgical complication. Our study demonstrates that wire-free localisation using SAVI SCOUT^® is an effective and time-efficient alternative to WGL with excellent physician and patient acceptance.

The ability to accurately retain the binding between the features of different objects is a critical element of visual working memory. The underlying mechanism can be elucidated by analyzing correlations of response errors in dual-report experiments, in which participants have to report two features of a single item from a previously viewed stimulus array. Results from separate previous studies using different cueing conditions have indicated that location takes a privileged role in mediating binding between other features, in that largely independent response errors have been observed when location was used as a cue, but errors were highly correlated when location was one of the reported features. Earlier results from change detection tasks likewise support such a special role of location, but they also suggest that this role is substantially reduced for longer retention intervals in favor of object-based representation. In the present study, we replicated the findings of previous dual-report tasks with different cueing conditions, using matched stimuli and procedures. Moreover, we show that the observed patterns of error correlations remain qualitatively unchanged with longer retention intervals. Fits with neural population models demonstrate that the behavioral results at long, as well as short, delays are best explained by memory representations in independent feature maps, in which an item’s features are bound to each other only via their shared location.