Chronic bacterial osteomyelitis: prospective comparison of 18F-FDG imaging with a dual-head coincidence camera and 111In-labelled autologous leucocyte scintigraphy

Abstract

Indium-111-labelled white blood cells ((111)In-WBCs) are currently considered the tracer of choice in the diagnostic work-up of suspected active chronic osteomyelitis (COM). Previous studies in a limited number of patients, performed with dedicated PET systems, have shown that [(18)F]2'-deoxy-2-fluoro- D-glucose (FDG) imaging may offer at least similar diagnostic accuracy. The aim of this prospective study was to compare FDG imaging with a dual-head coincidence camera (DHCC) and (111)In-WBC imaging in patients with suspected COM. Thirty consecutive non-diabetic patients with possible COM underwent combined skeletal scintigraphy (30/30 patients), (111)In-WBC imaging (28/30 patients) and FDG-PET with a DHCC (30/30 patients). During diagnostic work-up, COM was proven in 11/36 regions of suspected skeletal infection and subsequently excluded in 25/36 regions. In addition, soft tissue infection was present in five patients and septic arthritis in three. (111)In-WBC imaging in 28 patients was true positive in 2/11 regions with proven COM and true negative in 21/23 regions without further evidence of COM. False-positive results occurred in two regions and false-negative results in nine regions suspected for COM. Most of the false-negative results (7/9) occurred in the central skeleton. If the analysis was restricted to the 18 regions with available histology ( n=17) or culture ( n=1), (111)In-WBC imaging was true positive in 2/18 regions, true negative in 8/18 regions, false negative in 7/18 regions and false positive in 1/18 regions. FDG-DHCC imaging was true positive in 11/11 regions with proven COM and true negative in 23/25 regions without further evidence of COM. False-positive results occurred in two regions. If the analysis was restricted to the 19 regions with available histology ( n=18) or culture ( n=1), FDG-DHCC imaging was true positive in 9/9 regions with proven COM and true negative in 10/10 regions without further evidence of COM. It is concluded that FDG-DHCC imaging is superior to (111)In-WBC scintigraphy in the diagnosis of COM in the central skeleton and therefore should be considered the method of choice for this indication. This seems to hold true for peripheral lesions as well, but in our series the number of cases with proven infection was too small to permit a final conclusion.

Imaging of Inflammation by PET, Conventional Scintigraphy, and Other Imaging Techniques

“…18 F-FDG PET has also been evaluated in patients with osteomyelitis. PET has been shown to offer an excellent sensitivity, normally reaching or exceeding 95%, with high specificities above 87% (7,8). In spondylitis and spondylodiscitis, PET combines high sensitivity with high specificity (9-11).…”

EANM/SNMMI Guideline for18F-FDG Use in Inflammation and Infection

“…• Peripheral bone osteomyelitis (nonpostoperative, nondiabetic foot) (16)(17)(18)(19)(20)(21)(22)(23).…”

Positron emission tomography in spinal infections

“…In one such study, Guhlmann et al [26] highlighted significantly better accuracy of the 18F-FDG PET compared to radiolabeled antigranulocyte antibody in patients with suspected chronic osteomyelitis of the central skeleton including the spine. In a similar study, Meller et al [27] reported that 18F-FDG PET was superior to radiolabeled leukocyte scintigraphy in the axial skeleton. In eight patients, the field of interest was the spine, and 18F-FDG PET showed 100% diagnostic accuracy.…”