Abstract:
Objective
To study the feasibility of metal nanoprobe BaGdF5-PEG as the novel contrast agent in computed-tomography lymphography (CT-LG) used for detection of sentinel lymph nodes(SLNs) in rabbits.
Methods
The metal nanoprobe BaGdF5-PEG was synthesized by the hydrothermal method and further modified using HS-PEG2000-NH2 as stabilizing agents. BaGdF5-PEG was evaluated by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). Six healthy female New Zealand rabbits underwent CT-LG after subcutaneous injection of 0.5 ml BaGdF5-PEG in sub-areolar area of the right second breast. CT images were taken before and 1, 5, 10, 30, 40, 60, 90 min after contrast agent injection. The scanning ranged from the whole axilla to the area beneath the second breast. SLNs were recognized in CT-LG image. CT value of SLNs at different time points was recorded and expressed as ±s. According to Suga et al's method, if the peak CT value of SLNs was 30 HU higher than that of plain scanning, it was considered as enhancement effect. After CT-LG, sentinel lymph node biopsy (SLNB) was performed in rabbits, with methylene blue as tracer. The results of CT-LG were compared with the results of SLNB.
Results
The TEM image demonstrated that the prepared metal nanoparticles BaGdF5 was square in shape,with a mean diameter of 20 nm. The hydrated diameter of metal nanoprobe BaGdF5-PEG was 52 nm after modification. The involved elements (Ba, Gd and F) were all showed in EDX spectrum. CT-LG with BaGdF5-PEG as a contrast agent enabled the visualization of 6 SLNs (one in each rabbit), which was consistent with the results of SLNB. CT value of SLNs was (12.8±5.0) HU before injecting the contrast agent and reached a peak value of (47.4 ±9.1) HU 10 min after injecting the contrast agent, which was more than 30 HU higher than that of plain scanning.
Conclusion
The metal nanoprobe BaGdF5-PEG can be used as a contrast agent of CT-LG, which provides long-time visualization of SLNs in the breasts of rabbits.
Key words:
Metal nanoparticles,
Lymph node,
Lymphography
Qiuhu Wang, Tao Wang, Dongwei Su, Chao Cheng, Changjing Zuo. Experimental study of metal nanoprobe BaGdF5-PEG as novel contrast agent in computed-tomography lymphography[J]. Chinese Journal of Breast Disease(Electronic Edition), 2017, 11(03): 138-143.