Interventional Optical Molecular Imaging Guidance during Percutaneous Biopsy

Abstract

Purpose:To investigate indocyanine green (ICG) as a molecular beacon for malignant lesions within the liver and evaluate the ability of a developed handheld imaging system to allow measurement of ICG fluorescence within focal hepatic lesions with high target-to-background ratios in a mouse model. Materials and Methods:All animal experiments were approved by the institutional animal care committee. A handheld optical molecular imaging device was constructed to pass through the introducer needle of a standard percutaneous biopsy kit. An ex vivo phantom system was constructed to quantify tissue attenuation properties of ICG in liver parenchyma. Subsequently, intrahepatic colorectal cancer metastases were generated in nude mice, and epifluorescence imaging of ICG, as well as histologic analysis of the explanted livers, was performed at 3 weeks after implantation (n = 6). Epifluorescence imaging with the handheld imaging device was then performed on intrahepatic colorectal metastases after the administration of ICG (n = 15) at 3, 6, and 24 hours after injection. Target-to-background ratios were calculated for each time point. Subsequently, a core biopsy of intrahepatic colorectal metastases was performed by using a standard clinical 18-gauge biopsy needle. Results:There was avid localization of ICG to the focal lesions at all time points. Similarly, fluorescence within the tumors was greater than that within normal liver, as detected with the handheld imaging system (mean target-to-background ratio 6 standard deviation, 3.9 6 0.2 at 24 hours). A core biopsy of tumor and normal adjacent liver by using a standard biopsy needle demonstrated a sharp margin of fluorescence intensity at the tumor-liver interface. Conclusion:The custom-designed molecular imaging device, in combination with ICG, readily allowed differentiation between normal and malignant tissue in a murine model of intrahepatic colorectal metastasis.q RSNA, 2014

Imaging of Liver Tumors Using Surface-Enhanced Raman Scattering Nanoparticles

“…1, 2, 11, 34, 35 In order to assess if SERS NPs might have advantages over this established technique, we performed direct in vitro and in vivo comparisons.…”

“…2, 10, 11, 34, 35, 37 These methods are based on fundamentally different principles than nanoparticle-based imaging. First, ICG is a small molecule fluorescent dye, and its uptake into liver malignancies is still only partially understood.…”

Image-Guided Biopsy in the Era of Personalized Cancer Care: Proceedings from the Society of Interventional Radiology Research Consensus Panel

“…However, real-time fusion imaging platforms are often bulky and used more frequently at specialized centers, rendering them less generalizable to allow for molecular imaging guidance during biopsy. Another approach is to develop biopsy devices capable of detecting molecular tracers in the tumor tissue, allowing for more accurate intra-procedural tissue sampling [22,23]. For example, a biopsy device that incorporates a needle gamma detector allows for real-time intra-procedural detection of a molecular tracer (F18) during the biopsy [22].…”

“…With its high degree of sensitivity, high spatial resolution, real-time image display, and 3D imaging, the addition of optical imaging to biopsy procedures has the potential to improve image guidance and decrease the risk of sampling error. However, any optical biopsy system would need to be compatible with the existing clinical armamentarium of needles, sheaths, and catheters [23]. …”

Pharmacodynamic endpoints as clinical trial objectives to answer important questions in oncology drug development

“…One might envision individual biopsy procedures being replaced with central access points or in-place guide needles for repeated tumor sampling. There is already considerable R&D effort in the design and development of smart biopsy needles containing sensors that will provide physicians with real-time feedback about the characteristics of the tissue through which the biopsy needle is passing [45-48]. …”