Objective: The objective of this study was to compare the biodistribution and PET imaging of (11)C-PDT and (18)F-FDG in a mouse model of lung adenocarcinoma, and to evaluate the value of (11)C-PDT as a new tracer for PET imaging of lung cancer.
Methods: Twenty four lung adenocarcinoma-bearing mice were randomly divided into two groups, 12 each. The mice received (11)C-PDT or (18)F-FDG injection i.v. respectively. The biodistribution of (11)C-PDT or (18)F-FDG in the mice was measured with a well-gamma detector at 60 min after injection. The PET imagings of mice were performed using either of the two tracers.
Results: Considerable uptake of the both radioactive tracers in the tumors was observed. The tumor uptake of (11)C-PDT [(0.65 +/- 0.20)%ID/g] was significantly lower than that of (18)F-FDG [(7.44 +/- 1.56)%ID/g, P < 0.01]. In the (11)C-PDT group, the highest uptake was observed in the liver, kidney and blood in a successively declining order, while the highest uptake of (18)F-FDG was seen in a order of heart, tumor and kidneys. The tumor/muscle ratio of (11)C-PDT uptake was relatively high (2.02 +/- 0.56), but still lower than that of (18)F-FDG (2.95 +/- 0.49, P < 0.01). All values of other tumor/organ ratios (T/NT) of (11)C-PDT uptake were < 2. High radioactive uptake was showed in the tumor and abdominal organs on PET images in the tumor-bearing mice injected with (11)C-PDT, and (18)F-FDG uptake was showed in the heart, tumor and abdominal organs. The tumor PET images with (11)C-PDT and (18)F-FDG were all clear.
Conclusion: The uptake of (11)C-PDT in lung cancer is higher than that in muscle tissues, and pulmonary cancers can be detected by PET imaging. (11)C-PDT may be a promising PET tracer for lung cancers.