Efficacy of intraoperative specimen radiography as margin assessment tool in breast conserving surgery.

Purpose: To explore the ability of intraoperative specimen radiography (SR) to correctly identify positive margins in patients receiving breast conserving surgery (BCS). To assess whether the reoperation rate can be reduced by using this method.

Methods: This retrospective study included 470 consecutive cases receiving BCS due to a primarily diagnosed breast cancer. SR was carried out in two planes, assessing the specimen regarding the presence of the lesion and its relation to all margins. If indicated, re-excision of selective orientations was advised. Under consideration of gross inspection and the SR-findings, it was up to the surgeon whether to perform re-resections. The recommendations for re-excision were, separately for each orientation, compared to the histopathological results, serving as gold standard.

Results: Intraoperative SR was performed in 470 cases, thus 2820 margins were assessed. Of those, 2510 (89.0%) were negative and 310 (11.0%) positive. SR identified 2179 (77.3%) margins correctly as negative, whereas 331 (11.7%) clear margins were misjudged as positive. Of 310 infiltrated margins, SR identified 114 (4.0%) correctly, whereas 196 (7.0%) infiltrated margins were missed. This resulted in a sensitivity/specificity of 36.8%/86.8% and PPV/NPV of 25.6%/91.8%. Through targeted re-resections positive margins could be reduced by 31.0% [310 to 214 (7.6%)]. On case level, the rate of secondary procedures could be reduced by 37.0% [from 162 to 102 (21.7%)].

Conclusions: SR is a helpful tool to identify infiltrated margins and to reduce the rate of secondary surgeries by recommending targeted re-excisions of according orientations in order to obtain a final negative margin status.