Evaluation of an intraperitoneal ovarian cancer syngeneic mouse model using ¹⁸F-FDG MicroPET imaging

Objectives: The objective of this study was to evaluate the syngeneic immunocompetent mouse model by using the micro-positron emission tomography with 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (¹⁸F-FDG microPET) imaging of ovarian tumor growth. Methods: ID8 ovarian carcinoma cells derived from C57BL/6 mice were intraperitoneally injected into female C57BL/6 mice. Mice were injected with ¹⁸F-FDG (7.4 MBq, intravenous injection), and microPET images were obtained 40 minutes later. Microcomputed tomographic images were also obtained immediately after microPET images for anatomical reference. ¹⁸F-FDG microPET images were acquired at baseline and at 4, 8, 10, and 11 weeks after tumor cell injection. The maximum standardized uptake value (SUV_max) in each time point was obtained from the images and compared to follow the tumor growth. Results: Physiological uptake of ¹⁸F-FDG was intensely found in the bladder and heart and frequently in the gastrointestinal tract. Diffused uptake of ¹⁸F-FDG was observed in the peritoneal cavity of all tumor-bearing mice at 4 weeks, and high focal uptakes were developed in the peritoneal cavity at 8 to 11 weeks. High focal uptakes increased over time, correlating with a progressive increase in the SUV_max of ¹⁸F-FDG. At 11 weeks, the SUV_max value was significantly increased (1.49 ± 0.10 at 11 weeks vs 0.29 ± 0.03 at baseline, P < 0.01). Tumors in the gut and peritoneum were confirmed by anatomical and histopathological examination. Conclusions: Our results demonstrate that the peritoneal tumor growth in the syngeneic ovarian cancer model can be detected by the ¹⁸F-FDG microPET imaging.