Breast cancer is the most commonly occurring cancer in women. Currently, breast conservation surgery (BCS) is the treatment most often prescribed. BCS involves removing the tumor while conserving the greatest amount of healthy breast tissue. Under standard white light, tumor borders are difficult for the surgeons to visualize. Therefore, between 30-70% of patients require a second operation to remove remaining cancerous tissue that wasn't detected during the initial surgery. Thus, there is an urgent clinical need for a new imaging tool that improves tumor visualization during the first surgery. PRODIGI, a new hand-held optical imaging device, uses a safe violet-blue light to detect fluorescence signals in the tissue. Different tissues are associated with specific fluorescent colors and therefore the device can be used to differentiate between tumor and healthy breast tissue. Based on previous clinical data, PRODIGI can distinguish some tumors from normal tissues, but is not specific enough to detect a difference across all breast tumor types. The fluorescent contrast drug 5-aminolevulinic acid (5-ALA) accumulates in tumors naturally and previous research has shown that 5-ALA increases tumor-normal tissue fluorescence contrast. In this observational clinical study, PRODIGI and 5-ALA will be used to visualize tumor borders during BCS. 5-ALA induced fluorescent images from the surgical sample and the surgical bed obtained by PRODIGI will be compared retrospectively with the images taken under standard white light and/or autofluorescence. The technology's ability to accurately identify tumor borders better than conventional practice will be confirmed by tissue pathology.