Objective: Wegener's granulomatosis (WG) is a rare disorder characterized by granulomatous necrotizing vasculitis which mainly affects small- and medium-sized vessels. While the classical triad of involvement is upper and lower respiratory system and glomerulonephritis, WG may involve any organ or system in the body. The aim of our study was to investigate the role of positron emission tomography/computerized tomography (PET/CT) both in the initial evaluation and follow-up of patients with WG.
Methods: We retrospectively evaluated PET/CT data from 13 patients (6 males; 7 females) with a mean age of 45 ± 12.4 years (range 28-63) who underwent either initial evaluation (n = 12) or response evaluation (n = 2) by conventional imaging methods and FDG with PET/CT. PET/CT images were both visually and quantitatively evaluated. The demographic data, clinical and laboratory findings of each patient were also recorded from the hospital files.
Results: Lung (n = 13), parapharyngeal space (n = 8), nose (n = 8), and ear (n = 3) were the most common disease sites detected on PET/CT. The entire initial evaluation patients had either solitary or multiple pulmonary nodular/mass lesions with marked increased FDG uptake (mean SUVmax 12 ± 4, range 3.53-19.51) on PET/CT. There was no significant pathological FDG uptake in patients consistent with complete treatment response after appropriate immunosuppressive therapy. PET/CT clearly demonstrated unexpected disease sites besides the respiratory system, with WG involvement except kidneys. Possibly due to physiological urinary excretion of FDG, urine analysis, BUN and creatinine levels were accepted still the best way for diagnosis of renal involvement.
Conclusion: FDG with PET/CT is a valuable tool in the management of patients with WG for a more accurate clinical evaluation regarding disease extension and treatment response.