PURPOSE: To determine the accuracy of a handheld ultrasound-guided optoacoustic tomography (US-OT) probe developed for human deep-tissue imaging in ex vivo assessment of tumor margins postlumpectomy. METHODS: A custom-built two-dimensional (2D) US-OT–handheld probe was used to scan 15 lumpectomy breast specimens. Optoacoustic signals acquired at multiple wavelengths between 700 and 1100 nm were reconstructed using model linear algorithm, followed by spectral unmixing for lipid and deoxyhemoglobin (Hb). Distribution maps of lipid and Hb on the anterior, posterior, superior, inferior, medial, and lateral margins of the specimens were inspected for margin involvement, and results were correlated with histopathologic findings. The agreement in tumor margin assessment between US-OT and histopathology was determined using the Bland–Altman plot. Accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of margin assessment using US-OT were calculated. RESULTS: Ninety margins (6 × 15 specimens) were assessed. The US-OT probe resolved blood vessels and lipid up to a depth of 6 mm. Negative and positive margins were discriminated by marked differences in the distribution patterns of lipid and Hb. US-OT assessments were concordant with histopathologic findings in 87 of 89 margins assessed (one margin was uninterpretable and excluded), with diagnostic accuracy of 97.9% (kappa = 0.79). The sensitivity, specificity, PPV, and NPV were 100% (4/4), 97.6% (83/85), 66.7% (4/6), and 100% (83/83), respectively. CONCLUSION: US-OT was capable of providing distribution maps of lipid and Hb in lumpectomy specimens that predicted tumor margins with high sensitivity and specificity, making it a potential tool for intraoperative tumor margin assessment.

目的：确定为人类深部组织成像开发的手持式超声引导光声层析成像（US-OT）探针在肿块切除术后离体评估中的准确性。方法：使用定制的二维（2D）US-OT手持式探头扫描了15个乳房切除术的乳房标本。使用模型线性算法重建在700至1100 nm之间的多个波长处采集的光声信号，然后对脂质和脱氧血红蛋白（Hb）进行光谱分解。检查血脂和血红蛋白在标本的前，后，上，下，中和外侧边缘上的分布图，以检查边缘是否受累，并将结果与​​组织病理学发现相关联。US-OT与组织病理学之间在肿瘤切缘评估中的一致性是使用Bland-Altman图确定的。使用US-OT计算边缘评估的准确性，敏感性，特异性，阳性预测值（PPV）和阴性预测值（NPV）。结果：评估了90个边缘（6×15个样本）。US-OT探针可分辨血管和脂质，深度可达6毫米。血脂和血红蛋白分布模式的显着差异区分了阴性和阳性边缘。US-OT评估与评估的89个切缘中的87个切缘组织病理学结果一致（一个切缘无法解释和排除），诊断准确性为97.9％（kappa = 0.79）。敏感性，特异性，PPV和NPV分别为100％（4/4），97.6％（83/85），66.7％（4/6）和100％（83/83）。结论： US-OT能够提供高灵敏度和特异性预测肿瘤切缘的肿块切除标本中脂质和Hb的分布图，使其成为术中评估肿瘤切缘的潜在工具。