Whole-body 18F-FDG PET/CT is superior to CT as first-line diagnostic imaging in patients referred with serious nonspecific symptoms or signs of cancer: A randomized prospective study of 200 patients

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Anne Mette Lebech, Anne Gaardsting, Annika Loft, Jesper Graff, Elena Markova, Anne Kiil Bertelsen, Jan Lysgard Madsen, Kim Francis Andersen, Eric Von Benzon, Morten Helms, Lars R. Mathiesen, Kim P. David, Gitte Kronborg, Andreas Kjaer

A fast-track pathway has been established in Denmark to investigate patients with serious nonspecific symptoms and signs of cancer (NSSC), who are not eligible to enter an organ-specific cancer program. The prevalence of cancer in this cohort is approximately 20%. The optimal screening strategy in patients with NSSC remains unknown. The aim of the study was to investigate whether 18F-FDG PET/CT was superior to CT as an initial imaging modality in patients with NSSC. In a randomized prospective trial, the imaging modalities were compared with regard to diagnostic performance. Methods: Two hundred patients were randomized 1:1 to whole-body 18F-FDG PET/CT or CT of the thorax and abdomen as the imaging modality. A tentative diagnosis was established after first-line imaging. The final referral diagnosis was adjudicated by the physician, when sufficient data were available. Results: One hundred ninety-seven patients were available for analysis because 3 patients withdrew consent before scanning. Thirty-nine (20%) patients were diagnosed with cancer, 10 (5%) with an infection, 15 (8%) with an autoimmune disease, and 76 (39%) with other diseases. In the remaining 57 patients (28%), no specific disease was found. 18F-FDG PET/CT had a higher specificity (96% vs. 85%; P 5 0.028) and a higher accuracy (94% vs. 82%; P 5 0.017) than CT. However, there were no statistically significant differences in sensitivity (83% vs. 70%) or negative predictive values (96% vs. 92%). No difference in days to final referral diagnosis according to randomization group could be shown (7.2 vs. 7.6 d). However, for the subgroups in which the imaging modality showed a suggestion of malignancy, there was a significant delay to final diagnosis in the CT group compared with the 18F-FDG PET/CT group (11.6 vs. 5.7 d; P 5 0.02). Conclusion: Compared with CT, we found a higher diagnostic specificity and accuracy of 18F-FDG PET/CT for detecting cancer in patients with NSSC. 18F-FDG PET/CT should therefore be considered as first-line imaging in this group of patients.

Original languageEnglish
JournalJournal of Nuclear Medicine
Volume58
Issue number7
Pages (from-to)1058-1064
Number of pages7
ISSN0161-5505
DOIs
Publication statusPublished - Jul 2017

    Research areas

  • FDG-PET/CT; molecular imaging; cancer; prospective study; randomized study

ID: 188152698