PET IMAGING OF NON-SMALL-CELL LUNG-CARCINOMA WITH CARBON-11-METHIONINE - RELATIONSHIP BETWEEN RADIOACTIVITY UPTAKE AND FLOW-CYTOMETRIC PARAMETERS

Carbon-11-methionine PET scans were obtained from 24 patients with non -small-cell lung carcinoma for whom surgical treatment was considered. The tumor mass was visualized with clear delineation. After PET scann ing, the tumor was removed by lobectomy or pulmonectomy. The tumor tis sue was first processed to yield tumor cell suspensions and then subje cted to DNA flow cytometry. Comparison between C-11 uptake rate and fl ow-cytometric data gave the following results: C-11 uptake rate in the tumor correlated well with the cellular DNA content (DNA index) of tu mor cells at the resting state of cell division (GO + G1-phase) (r = 0 .67). The correlation between C-11 uptake rate and S-phase cell percen tage was markedly high (r = 0.76), and the correlation between C-11 up take rate and S + G2/M-phase cell percentage was extremely high (r = 0 .86). It was concluded that the tumor uptake rate of C-11-methionine w as representive of tumor growth rate in this tumor type.