Pleijhuis Rick, Timmermans Arwin, De Jong Johannes, De Boer Esther, Ntziachristos Vasilis, Van Dam Gooitzen
Department of Surgery, University Medical Center Groningen.
Helmholtz Zentrum Munich, Technical University of Munich.
J Vis Exp. 2014 Sep 19(91):51776. doi: 10.3791/51776.
Inaccuracies in intraoperative tumor localization and evaluation of surgical margin status result in suboptimal outcome of breast-conserving surgery (BCS). Optical imaging, in particular near-infrared fluorescence (NIRF) imaging, might reduce the frequency of positive surgical margins following BCS by providing the surgeon with a tool for pre- and intraoperative tumor localization in real-time. In the current study, the potential of NIRF-guided BCS is evaluated using tissue-simulating breast phantoms for reasons of standardization and training purposes. Breast phantoms with optical characteristics comparable to those of normal breast tissue were used to simulate breast conserving surgery. Tumor-simulating inclusions containing the fluorescent dye indocyanine green (ICG) were incorporated in the phantoms at predefined locations and imaged for pre- and intraoperative tumor localization, real-time NIRF-guided tumor resection, NIRF-guided evaluation on the extent of surgery, and postoperative assessment of surgical margins. A customized NIRF camera was used as a clinical prototype for imaging purposes. Breast phantoms containing tumor-simulating inclusions offer a simple, inexpensive, and versatile tool to simulate and evaluate intraoperative tumor imaging. The gelatinous phantoms have elastic properties similar to human tissue and can be cut using conventional surgical instruments. Moreover, the phantoms contain hemoglobin and intralipid for mimicking absorption and scattering of photons, respectively, creating uniform optical properties similar to human breast tissue. The main drawback of NIRF imaging is the limited penetration depth of photons when propagating through tissue, which hinders (noninvasive) imaging of deep-seated tumors with epi-illumination strategies.
术中肿瘤定位不准确以及手术切缘状态评估不当会导致保乳手术（BCS）的效果不理想。光学成像，尤其是近红外荧光（NIRF）成像，可能通过为外科医生提供实时术前和术中肿瘤定位工具来降低BCS后手术切缘阳性的发生率。在本研究中，出于标准化和培训目的，使用组织模拟乳腺模型评估NIRF引导下BCS的潜力。具有与正常乳腺组织相当光学特性的乳腺模型用于模拟保乳手术。将含有荧光染料吲哚菁绿（ICG）的肿瘤模拟内含物在预定位置纳入模型中，并对其进行成像以用于术前和术中肿瘤定位、实时NIRF引导下的肿瘤切除、NIRF引导下的手术范围评估以及术后手术切缘评估。使用定制的NIRF相机作为成像的临床原型。含有肿瘤模拟内含物的乳腺模型提供了一种简单、廉价且通用的工具来模拟和评估术中肿瘤成像。凝胶状模型具有与人组织相似的弹性特性，并且可以使用传统手术器械进行切割。此外，模型分别含有血红蛋白和脂质乳剂以模拟光子的吸收和散射，从而产生与人类乳腺组织相似的均匀光学特性。NIRF成像的主要缺点是光子在组织中传播时穿透深度有限，这阻碍了使用落射照明策略对深部肿瘤进行（非侵入性）成像。
