OBJECTIVEThe 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.

METHODSTwenty 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.

RESULTSConsiderable 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.

CONCLUSIONThe 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.