The Synthesis and Evaluations of the 68Ga-Lissamine Rhodamine B (LRB)‎ as a New Radiotracer for Imaging Tumors by Positron Emission Tomography

Abstract EN

Purpose.

The aim of this study is to synthesize and evaluate 68Ga-labeled Lissamine Rhodamine B (LRB) as a new radiotracer for imaging MDA-MB-231 and MCF-7 cells induced tumor mice by positron emission tomography (PET).

Methods.

Firstly, we performed the radio synthesis and microPET imaging of 68Ga(DOTA-LRB) in athymic nude mice bearing MDA-MB-231 and MCF-7 human breast cancer xenografts.

Additionally, the evaluations of 18F-fluorodeoxyglucose (FDG), as a glucose metabolism radiotracer for imaging tumors in the same xenografts, have been conducted as a comparison.

Results.

The radiochemical purity of 68Ga(DOTA-LRB) was >95%.

MicroPET dynamic imaging revealed that the uptake of 68Ga(DOTA-LRB) was mainly in normal organs, such as kidney, heart, liver, and brain and mainly excreted from kidney.

The MDA-MB-231 and MCF-7 tumors were not clearly visible in PET images at 5, 15, 30, 40, 50, and 60 min after injection of 68Ga(DOTA-LRB).

The tumor uptake values of 18F-FDG were 3.79±0.57 and 1.93±0.48%ID/g in MDA-MB-231 and MCF-7 tumor xenografts, respectively.

Conclusions.

68Ga(DOTA-LRB) can be easily synthesized with high radiochemical purity and stability; however, it may be not an ideal PET radiotracer for imaging of MDR-positive tumors.