Background: Intraoperative ultrasound guided surgery (IOUS) is an effective surgical technique for invasive breast cancer with advantages over wire localization (WL) including smaller resection volumes, lower rate of involved margins and better patient satisfaction. Nevertheless, there are few reports for ductal carcinoma in situ (DCIS) surgery. The objective of this study is to compare specimen margins and volume of excision for DCIS after IOUS vs WL. Material and methods: From February 2018 to December 2021, women diagnosed with DCIS eligible for breast conserving surgery guided by IOUS or WL were recorded into a prospectively maintained database. For IOUS surgery, after initial core biopsy, a US visible clip was placed at the biopsy site. At the time of surgery, distance from the clip to the end of microcalcifications in mammogram was assessed to guide the clip excision by IOUS. Specimen mammogram was performed to verify complete excision. Comparison was done for margin status, second surgeries and volume of excess of healthy breast tissue resected defined by the calculated resection ratio (CRR). Results: The study included 108 patients, 41 (37.96%) in the IOUS group and 67 (62.04%) in the WL group. IOUS patients were younger (p = 0.02) and had DCIS with comedonecrosis (p = 0.01). There were no differences in tumor size (p = 0.64) or grade (p = 0.93) between groups. IOUS showed smaller surgical volumes: 21.86 cm3 vs. 47.18 cm3 (p = 0.07) and significantly smaller CRR: 1.6 vs. 2.9 (p = 0.03). Two (4.8%) patients in the IOUS group had positive margins while 7 (10.4%) in the WL group. Re-excision rate was lower in the IOUS group (p = 0.08).Table:Baseline characteristicsIOUS (41 patients)WL (67 patients)pAge. Mean (Range)52.87 (35–78)57.76 (39–82)0.02DCIS size17.46 (4–50)17.06 (2–70)0.64DCIS grade0.93I13 (37.71%)1 (31.34%)II14 (34.15%)19 (28.36%)III14 (34.15%)27 (40.30%)Comedonecrosis0.001Yes8 (19.51%)3 (4.48%)No33 (80.49%)64 (95.52%)ER receptor0.86Positive35 (85.67%)8 (86.57%)Negative6 (14.63%)9 (13.43%)PR receptor0.18Positive33 (80.49%)46 (68.66%)Negative8 (19.51%)21 (31.34%)Clip placed after biopsy0.0001Yes41 (100%)15 (22.73%)No051 (77.27%)Re-excision for positive margins0.08Yes2 (4.88%)7 (10.45%)No39 (95.12%)60 (89.55%)Type of Re-excision0.45BCS2 (100%)5 (71.43%)Mastectomy02 (28.57%)Radiotherapy0.22Yes38 (92.68%)65 (97.01%)No3 (7.32%)2 (2.99%)Endocrine therapy0.35Yes34 (82.93%)58 (86.57%)No5 (12.20%)7 (10.44%)Patient refusal2 (4.88%)2 (2.99%)Oncoplastic surgery0.65Yes10 (24.39%)19 (28.36%)No31 (75.61%)48 (71.64%) Open table in a new tab No differences in DFS were observed (1 recurrence in the WL group vs 0 in the IOUS (p = 0.45)), FU of 18.17 months (Range 1.4–43 months). Conclusions: IOUS is an accurate localization method for guiding DCIS surgery. It decreases excision of healthy breast tissue while increasing rates of negative margins compared to WL. No conflict of interest. 

N. Rodríguez-Spiteri Sagredo

Papers

Intraoperative ultrasound is accurate for guiding breast conservative surgery in non-palpable ductal carcinoma in situ of the breast