Objective: To determine whether full-dose contrast-enhanced computed tomography (CT) (CECT) can be omitted from an 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) (FDG-PET)/CT staging examination in newly diagnosed FDG-avid lymphoma.
Methods: Twenty-nine patients with newly diagnosed FDG-avid lymphoma prospectively underwent unenhanced low-dose FDG-PET/CT and CECT. Different observers evaluated unenhanced low-dose FDG-PET/CT and CECT in a blinded manner. Ann Arbor stages according to unenhanced low-dose FDG-PET/CT and CECT were compared, and discrepancies between the 2 imaging modalities were resolved using bone marrow biopsy and posttreatment FDG-PET/CT as reference standard. Finally, it was assessed as to how many cases therapy would have been changed based on additional CECT findings.
Results: In 27 of 29 patients (93%; 95% confidence interval, 78%–98%), CECT either did not change or did not correctly change the Ann Arbor stage that was assigned according to unenhanced low-dose FDG-PET findings. In 2 of 29 patients (7%; 95% confidence interval, 2%–22%), CECT correctly provided another Ann Arbor stage than unenhanced low-dose FDG-PET/CT. In the latter 2 cases, therapy would not have been changed based on additional CECT findings.
Conclusions: Unenhanced low-dose FDG-PET/CT alone is suggested as the primary imaging modality of choice for staging patients with newly diagnosed FDG-avid lymphoma. This diagnostic approach is particularly indicated in younger patients in whom diagnostic radiation exposure should be minimized and in patients who are at increased risk of CT contrast-induced allergic reactions or nephropathy.
From the *Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands; †Department of Hematology, and ‡Department of Nuclear Medicine, Meander Medical Center Amersfoort, Amersfoort, The Netherlands.
Received for publication October 30, 2013; accepted January 2, 2014.
Reprints: Thomas C. Kwee, MD, PhD, Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands (e-mail: firstname.lastname@example.org).
This project was financially supported by the Dutch Organization for Health Research and Development (ZonMw) Program for Health Care Efficiency Research (grant number 80-82310-98-08012). Data collection, data analysis, interpretation of data, writing of the paper, and decision to submit were left to the authors’ discretion and were not influenced by ZonMw.
The authors declare no conflict of interest.