Prospective Diagnostic Performance of PET/CT Using the Novel Fibroblast Imaging Tracer [18F]-AlF-FAPI-74 Versus Standard of Care [18F]-FDG in Inflammatory Disorders
The aim of the study to evaluate the performance of new \[18F\]-AlF-FAPI-74 PET/CT in three inflammatory disorders (fever of unknown origin, IgG4-related disease and axial spondyloarthritis) and compare with the current stand-of-care \[18F\]-FDG PET/CT
• An illness of more than 3 weeks' duration,
• Temperature exceeding 38.3°C on \> 3 occasions, or elevated inflammatory markers on \> 3 occasions
• Diagnosis uncertain despite appropriate first-line investigations.
• High clinical suspicion of IgG4-RD by an experienced clinician of Internal Medicine, based on anamnesis, physical examination, first-line investigations and blood tests.
• Patients with a new diagnosis of IgG4-RD on histopathology and need for further assessment of disease extent with PET/CT,
• Relapse of diagnosed IgG4-RD on histopathology according to an experienced clinician of Internal Medicine
• High clinical suspicion of axial spondyloarthropahy according to an experienced rheumatology (based on inflammary back pain \> 3 months, insidious onset, morning stifness, improvement with exercise and worsening in rest, pain worse at night, age at onset \<45 years of age, imaging findings).
• Patient has persisting inflammatory back pain after 2 different types of NSAID's (tried for over 2-4 weeks), and is therefore eligible for biological DMARDS therapy.