Pretargeted radioimmunoimaging with a biotinylated D-D 3 construct and 99m Tc-DTPA-biotin: strategies for early diagnosis of small cell lung cancer

• Published in: Journal of international medical research 2020-07, Vol.48 (7), p.300060520937162
• Main Authors: Hong, Zhihui, Deng, Shengming, Shi, Yizhen, Xie, Yichi, You, Jiaxi, Wang, Wei, Huang, Hong, Liu, Zengli
• Format: Article
• Language: English
• Subjects: Animals; Biotin; Early Detection of Cancer; Lung Neoplasms - diagnostic imaging; Mice; Mice, Nude; Radioimmunodetection; Radiopharmaceuticals; Small Cell Lung Carcinoma - diagnostic imaging; Technetium; Technetium Tc 99m Pentetate; Tissue Distribution
• ISSN: 0300-0605; 1473-2300
• DOI: 10.1177/0300060520937162

Pro-gastrin releasing peptide (ProGRP) plays an oncogenic role in small cell lung cancer (SCLC). The anti-ProGRP monoclonal antibody D-D can selectively accumulate in SCLC xenografts in nude mice. This study evaluated the effectiveness of a new pretargeting procedure for the early diagnosis of SCLC. D-D was radiolabeled with technetium-99m ( Tc) using a three-step pretargeting method. Mice with SCLC xenografts were treated with different labeling regimens, and the biodistribution and radioimmunoimaging were explored. The percentage injected dose per gram (%ID/g) in various organs, tumor/non-tumor (T/NT) ratio, and tumor/background (T/B) ratio were also calculated. distribution experiments revealed that Tc-DTPA-biotin was metabolized in the liver and kidney, with rapid elimination in the blood. The T/B ratio was highest in mice treated with biotinylated antibody D-D  + avidin +  Tc-DTPA-biotin. Single-photon emission computerized tomography imaging further confirmed that the T/B ratio was highest in this group at all time points. In contrast to directly labeled D-D , pretargeting technology displayed specific enhancement and signal amplification in tumors, which could increase the target tumor uptake of Tc and provide a new approach for the early diagnosis of SCLC.