Detection of pulmonary metastases with the novel radiolabeled molecular probe 99mTc-RRL

摘要

Background: To improve the detection of pulmonary metastases, experimental blood-borne pulmonary metastasis mouse models were established using three intravenously administered cell lines. In a previous study we demonstrated that ^99mTc-radiolabeled arginine-arginine-leucine (RRL) could be used to non-invasively image malignant tumors. Methods: ^99mTc-RRL was prepared and injected intravenously in mice with pulmonary metastases that arose from the intravenous injection of HepG2, B16, and Hela cells. The bio-distribution and imaging of ^99mTc-RRL were determined in different pulmonary metastases mouse models and in normal mice. Results: ^99mTc-RRL exhibited higher uptake values in the lungs of pulmonary metastatic mice compared to normal mice (P<0.05; 3.92±0.48% ID/g 2 h post-injection and 3.89±0.36% ID/g 4 h post-injection in metastatic hepatic carcinoma [HepG2]-bearing lungs; 5.49±0.84% ID/g 2 h post-injection and 5.11±0.75% ID/g 4 h post-injection in metastatic melanoma [B16]-bearing lungs; 3.72±0.52% ID/g 2 h post-injection and 3.51±0.35% ID/g 4 h post-injection in metastatic cervical carcinoma [Hela]-bearing lungs; 2.38±0.20% ID/g 2 h post-injection and 2.11±0.24% ID/g 4 h post-injection in normal lungs). The pulmonary metastatic lesions were clearly visualized using ^99mTc-RRL. Conclusions: ^99mTc-RRL exhibited favorable metastatic tumor targeting and imaging properties, thus highlighting its potential as an effective imaging probe for detection of pulmonary metastases. ^99mTc-RRL can be used as a reasonable supplement to ¹⁸F-FDG imaging in the non-invasive imaging of tumor angiogenesis.