Introduction: Clear margins are crucial in breast-conserving surgery (BCS). Intra-operative specimen X-rays have become standard practice. The primary outcome of this study was to determine that the correct use of the 3D specimen imaging system, compared to just 2D imaging, would have saved patients from further surgery. In addition, we analysed whether the margin re-excision rate would be lower if an experienced radiologist reviewed and reported the specimen X-rays intra-operatively.

Methods: A retrospective review of the intra-operative specimen images was undertaken by a single experienced breast surgeon and two consultant breast radiologists blinded to histopathology. They used the 3D specimen tomosynthesis function and measured the width of the closest margin for patients who required re-operations for positive margins. These were patients for whom the operating surgeon had originally estimated margins as ‘clear’ intra-operatively. Sensitivity and specificity of the surgeon and radiologist reporting of margins was calculated compared to the histopathological assessment.

Results: Fifty-four patients were included. Eighty-one out of 216 (37.5%) margins were positive on histology. Forty-four margins (54.3%) were assessed accurately as involved by the radiologists and 25 (30.9%) by the surgeon using the 3D tomosynthesis function. Eleven (20%) patients might have been saved from a second operation if the surgeon adequately assessed the images using the specimen 3D tomosynthesis, and 27 (50%) of patients if reported intra-operatively by a breast radiologist.

Conclusion: Our study demonstrates that the intra-operative use of the 3D specimen tomosynthesis function could potentially save 20-50% of patients from a second operation. Without considering pass-through elements, re-excision of breast margins cost our hospital £211,004 (averaging £3,638 unit cost) for the 2022/2023 period. Those costs can be reduced significantly if the 3D specimen tomosynthesis function is used regularly intraoperatively. The authors propose that if surgeons receive adequate training they may become proficient to conduct most of the analysis, allowing radiologists to be more of a safety net with a second opinion, similar to practice in the U.S.