尽管存在所有可用的肿瘤定位方法，但保乳手术（BCS）仍然是一种盲目的手术。术中超声（IOUS）可以在所有切除阶段实时可视化。本研究是在2021年1月至2022年6月期间在威尼托肿瘤研究所进行的一项前瞻性观察性队列研究。招募了患有导管内乳管原位癌、T1-2浸润性癌或术前新辅助治疗后的病变适合BCS的患者。包括了所有乳腺癌病变类型，即固体可触及病变、固体不可触及病变、非固体不可触及病变和术前新辅助治疗后残留病变。符合条件的参与者以1:1的比例随机分配到IOUS组和传统手术（TS）组。主要结果包括手术切缘受累、再手术率、最靠近切缘宽度、主标本和腔内刮除切缘体积、过剩健康组织切除和计算切除率（CRR）。总共招募了160名患者：TS组80名患者，IOUS组80名患者。IOUS显著减少了标本体积（16.8 cm3 [10.5-28.9] vs. 24.3 cm3 [15.0-41.3]，p = 0.015），并具有更大的最靠近切缘宽度（未经TS处理的2.0 mm [1.0-4.0] vs. 1.0 mm [0.5-2.0]，p < 0.001）。IOUS后肿瘤体积与标本体积的比率显著提高（4.7% [2.5-9.1] vs. 2.9% [0.8-5.2]，p < 0.001）。IOUS的CRR明显优于TS（84.5% [46-120.8] vs. 114% [81.8-193.2]，p < 0.001），受累切缘率较低（2.5 vs. 15%，p = 0.009），重新切除率降低（2.5 vs. 12.5%，p = 0.032）。IOUS在BCS期间可以实时可视化切缘并进行持续控制。对于所有乳腺癌病变类型，在肿瘤学和外科结果方面，它显示出明显的优势，这些结果不支持盲目乳腺手术的范式。© 2023年，外科肿瘤学会。

Breast-conserving surgery (BCS) still remains a blind surgery despite all available tumor localization methods. Intraoperative ultrasound (IOUS) allows real-time visualization during all resection phases.This was a prospective observational cohort study conducted at the Veneto Institute of Oncology between January 2021 and June 2022. Patients with ductal carcinoma in situ, T1-2 invasive cancer, or post-neoadjuvant tumors, suitable for BCS, were recruited. All breast cancer lesion types were included, i.e. solid palpable, solid non-palpable, non-solid non-palpable, and post-neoadjuvant treatment residual lesions. Eligible participants were randomly assigned to either IOUS or traditional surgery (TS) in a 1:1 ratio. The main outcomes were surgical margin involvement, reoperation rate, closest margin width, main specimen and cavity shaving margin volumes, excess healthy tissue removal, and calculated resection ratio (CRR).Overall, 160 patients were enrolled: 80 patients were allocated to the TS group and 80 to the IOUS group. IOUS significantly reduced specimen volumes (16.8 cm3 [10.5-28.9] vs. 24.3 cm3 [15.0-41.3]; p = 0.015), with wider closest resection margin width (2.0 mm [1.0-4.0] vs. 1.0 mm [0.5-2.0] after TS; p < 0.001). Tumor volume to specimen volume ratio was significantly higher after IOUS (4.7% [2.5-9.1] vs. 2.9% [0.8-5.2]; p < 0.001). IOUS yielded significantly better CRR (84.5% [46-120.8] vs. 114% [81.8-193.2] after TS; p < 0.001), lower involved margin rate (2.5 vs. 15%; p = 0.009) and reduced re-excision rate (2.5 vs. 12.5%; p = 0.032).IOUS allows real-time resection margin visualization and continuous control during BCS. It showed clear superiority over TS in both oncological and surgical outcomes for all breast cancer lesion types. These results disfavor the paradigm of blind breast surgery.© 2023. Society of Surgical Oncology.