18F-Fluorodeoxyglucose Positron Emission Tomography in Elderly Patients with an Elevated Erythrocyte Sedimentation Rate of Unknown Origin

Abstract

Patients with an elevated erythrocyte sedimentation rate (ESR) and non-specific symptoms often pose a diagnostic dilemma. PET/CT visualises infection, inflammation and malignancy, all of which may cause elevated ESR. The objective of this study was to determine the contribution of 18F-fluorodeoxglucose positron emission tomography (PET/CT) in the diagnostic work-up of referred patients with an elevated ESR, in whom initial routine evaluation did not reveal a diagnosis. We conducted a combined retrospective (A) and prospective (B) study in elderly (>50 years) patients with a significantly elevated ESR of≥50 mm/h and non-specific complaints. In study A, 30 patients were included. Malignancy (8 patients), auto-inflammatory disease (8 patients, including 5 with large-vessel vasculitis) and infection (3 patients) were suggested by PET/CT. Two scans showed non-specific abnormalities and 9 scans were normal. Of the 21 abnormal PET/CT results, 12 diagnoses were independently confirmed and two alternative diagnosis were made. Two diagnoses were established in patients with a normal scan. In study B, 58 patients in whom a prior protocolised work-up was non-diagnostic, were included. Of these, 25 PET/CT-scans showed suspected auto-inflammatory disease, particularly large-vessel vasculitis (14 cases). Infection and malignancy was suspected in 5 and 3 cases, respectively. Seven scans demonstrated non-specific abnormalities, 20 were normal. Of the 40 abnormal PET/CT results, 22 diagnoses were confirmed, 3 alternative diagnoses were established. Only one diagnosis was established in the 20 patients with a normal scan. In both studies, the final diagnosis was based on histology, clinical follow-up, response to therapy or additional imaging. In conclusion, PET/CT may be of potential value in the diagnostic work-up of patients with elevated ESR if routine evaluation reveals no diagnosis. In particular, large-vessel vasculitis appears to be a common finding. A normal PET/CT scan in these patients suggests that it is safe to follow a wait-and-see policy.

Large-Vessel Vasculitis: Interobserver Agreement and Diagnostic Accuracy of18F-FDG-PET/CT

“…31 FDG-PET/CT scans were selected from the databases of the Department of Nuclear Medicine and PET Research of the VU University Medical Center (VUMC) and the Department of Nuclear Medicine and Molecular Imaging of the University Medical Center Groningen (UMCG). These FDG-PET/CT scans were performed in clinical practice in order to (1) determine the cause of inflammation of unknown origin ( n = 12) (this was a subset of patients from a study addressing the value of FDG-PET in patients with systemic inflammation of unknown origin) [ 14 ], (2) investigate whether large-vessel vasculitis was present in patients with diagnosed temporal arteritis ( n = 6) or polymyalgia rheumatic (PMR) ( n = 7), or (3) do a follow-up procedure in patients with a history of cancer ( n = 6) who were considered to be in clinical remission, from which a random selection was made.…”

The Role of18F-FDG PET/CT in Large-Vessel Vasculitis: Appropriateness of Current Classification Criteria?

“…Another recent study on IUO included 88 patients aged 50 years or older with nonspecific complaints and an ESR of more than 50 mm/h for which routine evaluation revealed no diagnosis. Of the 88 included patients 18 were diagnosed with LVV and 6 with PMR, with only one of these patients eventually diagnosed with temporal arteritis [ 46 ]. In both IUO studies parameters like the proportion of patients with disease, the contribution of 18 F-FDG PET/CT to the diagnosis, and the distribution of diseases in infection, NIID, and malignancy were similar to “fever of unknown origin” (FUO) patient populations [ 47 – 52 ].…”

Different Scoring Methods of FDG PET/CT in Giant Cell Arteritis

“… 1 In previously published studies, FDG-PET was found to have an added value for the initial diagnosis in patients with nonspecific symptoms (fever without known cause) to identify an area for biopsy, to evaluate the extent of the disease, and to evaluate the success or failure of therapy. 11 – 13 However, especially for the diagnosis of GCA based on FDG-PET both visual and semiquantitative methods have been published. In 2003, Meller et al 14 were the first to make the comparison between vascular uptake and liver uptake, using a 4-point scale (grade 0: no uptake, grade I: uptake lower than liver, grade II: similar to liver, and grade III: higher than liver).…”