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Intraoperative ultrasound for improvement of re-excision rates in breast-conserving surgery.

91 Background: Due to improved screening for early breast cancer, the percentages of small and nonpalpable breast tumors have significantly increased during the last decades. After lumpectomy, re-excision rates of 32%-63% have been reported and the routine placement of localization needles is painful, time-consuming, and costly. In this study we investigated the value of intraoperative ultrasound (IOUS) in the hand of the breast surgeon as a fast and cheap method for potentially improving unacceptable re-excision rates.


METHODS
Between July 2001 and December 2010, in 773 of 1,195 breast cancer patients a breast-conserving treatment has been performed at the certified breast care center Vorarlberg (breast-conservation rate 64.7%). In 74.9% (579/773) of the tumors IOUS was performed, of which 44% were nonpalpable and 56% were insufficiently palpable, respectively. 7.5-10 MHz linear ultrasound probes were used by four breast surgeons in combination with intraoperative macroscopic resection margin assessment by the pathologist for prospective evaluation of definitive resection margin status over time. Furthermore, local recurrence rates were assessed.


RESULTS
During the study period, 579 of the included primary tumors were detected by IOUS. The metachronous re-excision rate was halved from 22% (30/135) in the period 2001-2003 to 11% (13/121) between 2008 and 2010. Between 2001 and 2010 we achieved a total re-excision rate of 13% (74/579). In 53% of re-excision specimens, no residual tumor was present, in 23% DCIS and in 24% invasive tumor was found, respectively. At a median follow-up of 56.4 months, a local recurrence rate of 1.7% was observed using our approach of IOUS combined with intraoperative margin assessment.


CONCLUSIONS
IOUS in the hand of the breast surgeon proved to be a valuable, fast, and cheap method to improve metachronous re-excision rates in breast-conserving surgery. Patients can be spared the painful, costly, and time-consuming placement of a localization needle. Furthermore, tissue-sparing operations can be performed more easily and intraoperative specimen radiography can be avoided. The actual pathologic tumor size, however, is often being underestimated, especially regarding in situ cancers.