J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.
Med Phys. 2011 Nov;38(11):5873-8. doi: 10.1118/1.3641877.
Accurate identification of tumor margins presents a major challenge in the surgical treatment of human cancers. Inability of complete removal of tumor lesions after surgery causes local recurrence and increases the incidence of developing tumor metastasis. It is clear that novel approaches that allow defining tumor margins intraoperatively for removal of small tumor lesions in the surgical cavity is critical for improving prognosis of cancer patients. To facilitate image-guided surgery using targeted optical imaging probes, we have developed a reflection-mode fluorescence molecular tomography (FMT) system with a handheld probe that is able to provide three-dimensional tumor margin information.
The imaging method and system were validated using both simulated and phantom experiments. We further examined the accuracy of the handheld FMT system in an orthotopic mouse mammary tumor model following systemic delivery of near-infrared (NIR) dye-labeled and urokinase plasminogen activator receptor targeted magnet iron oxide nanoparticles.
Our results show that when the targets are located within 5 mm beneath the surface of the media, fluorescent images can be reliably detected and reconstructed with an average positional error of 0.5 mm laterally and 1.5 mm axially. For in vivo imaging in the mouse tumor model, the location and size of the tumor detected by FMT correlated well with that measured by the magnetic resonance imaging (MRI).
Our system can three-dimensionally image targets located at a depth of up to 7 mm. The in vivo results suggest that in combination with targeted optical imaging probes, this handheld FMT system can be potentially used as an intraoperative tool for the detection of tumor margins and for image-guided surgery.
在人类癌症的外科治疗中，准确识别肿瘤边缘是一个主要挑战。手术后不能完全切除肿瘤病灶会导致局部复发，并增加肿瘤转移的发生率。显然，需要新的方法来在手术过程中定义肿瘤边缘，以便切除手术腔中的小肿瘤病灶，这对于改善癌症患者的预后至关重要。为了促进使用靶向光学成像探针的图像引导手术，我们开发了一种具有手持式探头的反射模式荧光分子断层扫描（FMT）系统，该系统能够提供三维肿瘤边缘信息。
使用模拟和体模实验验证了成像方法和系统。我们还在系统性给予近红外（NIR）染料标记的和尿激酶型纤溶酶原激活物受体靶向磁氧化铁纳米颗粒后，在原位小鼠乳腺肿瘤模型中检查了手持式 FMT 系统的准确性。
我们的结果表明，当目标位于介质表面以下 5 毫米范围内时，可以可靠地检测和重建荧光图像，横向平均位置误差为 0.5 毫米，轴向平均位置误差为 1.5 毫米。在小鼠肿瘤模型的体内成像中，FMT 检测到的肿瘤位置和大小与磁共振成像（MRI）测量的结果非常吻合。
我们的系统可以三维成像深度达 7 毫米的目标。体内结果表明，结合靶向光学成像探针，这种手持式 FMT 系统可潜在地用作检测肿瘤边缘和图像引导手术的术中工具。
