Performance of FDG PET/ceCT in the evaluation of patients with lung cancer

The aim of this study was to assess the performance of FDG PET/ceCT simultaneously acquired, contemporary read and finally discussed by the radiologist and the nuclear medicine physician for staging and restaging lung cancer patients.

We analysed 17 consecutive patients (7F; 10M; mean age 68). Six patients were in staging, 8 patients were in restaging (1 during therapy, 2 after therapy and 5 during the follow-up) and 2 patients needed to characterise a suspect pulmonary mass. All the patients underwent combined FDG PET/CT and ceCT acquired simultaneously on the same tomograph. The images were read and reported together by the nuclear medicine physician and the radiologist.

None of the patients had adverse reactions nor complained about the procedure. Thirteen FDG PET/ceCT turned out positive, while 4 were completely negative. Among positive patients, a significant SUV max was detected in all the cases (range 1.8-17.5). In the end, 9 patients had a true positive result, 4 true negative, 3 false positive and 1 false negative. Sensitivity, specificity and accuracy of the combined procedure were 90%, 57% and 76% respectively. In 7/17 patients FDG PET/CT and ceCT were completely concordant. FDG PET/CT provided a significant impact on the final interpretation in 7/17 patients while ceCT had a major impact in 3/17 patients.

This preliminary study shows that FDG PET/ceCT is a feasible technique for lung cancer patients, providing an optimal sensitivity (90%). From our results it is advisable not to include patients without an histological diagnosis of cancer due to possible false positivity of the two methods, significantly reducing specificity. However, a proper patient selection is not easy and the future of this combined test relies essentially on the capacity to early identify only the subjects who would really benefit from both the procedures.