目的 采用契伦科夫光分子成像(Cerenkov luminescence imaging,CLI)技术对胃癌裸鼠移植瘤进行放射性核素光学分子成像,探索契伦科夫光诊断胃癌的可行性。方法 2只胃癌裸鼠移植瘤模型尾静脉分别注射1.67×10⁷ Bq ¹⁸F-FDG和3.34×10⁷ Bq ¹⁸F-FDG,1 h后采集契伦科夫光,选取相同大小的ROI进行信号强度分析。成像结束后解剖出移植瘤组织和肝、肾、心脏、胃肠道、肺脏再次成像。然后进行CLI动态成像:1只胃癌裸鼠移植瘤模型尾静脉注射1.67×10⁷ Bq ¹⁸F-FDG,分别于注药后40、60、80、100、120、140、160、180 min采集移植瘤部位的光学信号并进行对比。结果 移植瘤部位出现契伦科夫光信号的浓聚,契伦科夫光信号强度与尾静脉注射的¹⁸F-FDG的活度成正比,注射3.34×10⁷ Bq ¹⁸F-FDG和1.67×10⁷Bq ¹⁸F-FDG的胃癌移植瘤小鼠移植瘤部位光子数值分别为8.432×10⁵ p/s和3.172×10⁵ p/s。随时间的延长,移植瘤摄取¹⁸F-FDG的契伦科夫光信号逐渐减弱。结论 CLI可以实现胃癌裸鼠移植瘤的放射性核素光学成像,具有实现光学分子成像诊断胃癌的潜力。

Objective Using Cerenkov luminescence imaging, making radionuclide optical molecular imaging of gastric cancer xenograft in nude mice, to study the feasibility of Cerenkov luminescence in diagnosis of gastric cancer. Methods Two gastric cancer xenografts in nude mice were injected in tail vein with 1.67× 10⁷ Bq ¹⁸F-FDG and 3.34×10⁷ Bq ¹⁸F-FDG, respectively. Cerenkov luminescence images were taken 1 hour after, then the same size ROI was selected for signal strength analysis. After imaging, the nude mice were killed. Images of xenograft, liver, kidney, heart, gastrointestinal tract, and lung were also taken. Then Cerenkov luminescence dynamic imaging was performed. 1 gastric cancer xenograft in nude mice was injected in tail vein with 1.67×107Bq ¹⁸F-FDG. Images were taken respectively in 40,60,80,100,120,140,160,180 min after injection, then compared. Results The signal strengths of xenograft were stronger. The signal strength relied on the activity of ¹⁸F-FDG in tail vein injection. The photons of tumor on gastric cancer xenografts injected with 3.34×10⁷ Bq ¹⁸F-FDG and 1.67×10⁷ Bq ¹⁸F-FDG were 8.432×10⁵ p/s and 3.172×10⁵ p/s, respectively. The signal strength gradually weakened over time. Conclusions Cerenkov luminescence imaging can achieve gastric cancer xenograft in nude mice, with the potential of diagnosing gastric cancer by optical molecular imaging.