title: Diagnosis and follow-up of idiopathic retroperitoneal fibrosis: role of (18)F-FDG-PET/CT and biochemical parameters in patients with renal involvement.
abstract: Idiopathic retroperitoneal fibrosis (IRF) is a rare disease characterized by fibro-inflammatory reaction surrounding ureters and other inner organs with possible secondary renal involvement. Symptoms are aspecific and recurrent phases of activity are generally associated with elevation of inflammatory indices. 18F-FDG-PET is nowadays an important tool for the detection of this disease, allowing differentiation between metabolically active tissue and fibrotic one. The purpose of this study was to investigate the role of 18F-FDG-PET in the management of IRF and to evaluate possible correlations between biochemical parameters and PET/CT findings of disease activity. We enrolled seven consecutive patients with IRF (in five histology proved the disease) observed from 2003 to 2012 (5 M:2 F, mean age 53.8 years, range 44-86 years). All patients presented with fever as first symptom; two had obstructive renal failure requiring hemodialysis; one underwent monolateral nephrectomy for parenchyma infiltration; six presented ureteral involvement; three underwent ureteral stent placement. For each patient, during a mean total follow-up of 26.5 months we evaluated serum creatinine, BUN, Hb, RBCs, WBCs, PLT, CRP, ESR. Periodic 18F-FDG-PET/CT scans (every 5.9 months-mean) were performed in all patients. Statistical evaluation was performed using "stepwise regression" analysis. Steroids and immunosuppressive agents induced a progressive normalization of PET/CT scans in all patients at the end of follow-up. Stepwise regression analysis showed that BUN, serum creatinine and CRP only if considered together, significantly correlated with SUV max (p value = 0.000003057). 18F-FDG-PET is a useful tool for clinical decision making in patient with IRF, allowing to evaluate the efficacy of the pharmacological treatment and to detect early recurrences, to modify the therapeutic approach. Acute phase reactants are not reliable alone for the management and the follow-up as they are often not concordant with metabolic assessment of the disease. In patients with ureteral involvement, CRP together with BUN and serum creatinine has a significant correlation with PET/CT results, and can help physicians in therapeutic approach, better than a single parameter.
authors.affiliation: Nephrology and Dialysis Unit, Sant'Andrea Hospital, Second School of Medicine, Sapienza University of Rome, Rome, Italy. claudiafofi2@gmail.com.
authors.forename: Claudia
authors.initials: C
authors.lastname: Fofi
authors.affiliation: Department of Nuclear Medicine, Sant'Andrea Hospital, Second School of Medicine, Sapienza University of Rome, Rome, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Prosperi
authors.affiliation: Nephrology and Dialysis Unit, Sant'Andrea Hospital, Second School of Medicine, Sapienza University of Rome, Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Pettorini
authors.affiliation: Nephrology and Dialysis Unit, Sant'Andrea Hospital, Second School of Medicine, Sapienza University of Rome, Rome, Italy.
authors.forename: Francescaromana
authors.initials: F
authors.lastname: Festuccia
authors.affiliation: Department of Nuclear Medicine, Sant'Andrea Hospital, Second School of Medicine, Sapienza University of Rome, Rome, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Pirisino
authors.affiliation: Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Lanni
authors.affiliation: Department of Nuclear Medicine, Sant'Andrea Hospital, Second School of Medicine, Sapienza University of Rome, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Scopinaro
authors.affiliation: Nephrology and Dialysis Unit, Sant'Andrea Hospital, Second School of Medicine, Sapienza University of Rome, Rome, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Punzo
authors.affiliation: Nephrology and Dialysis Unit, Sant'Andrea Hospital, Second School of Medicine, Sapienza University of Rome, Rome, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Menè
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001806:Blood Urea Nitrogen; D002097:C-Reactive Protein / Q000032:analysis; D003404:Creatinine / Q000032:analysis / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010045:Outpatients / Q000706:statistics & numerical data; D000072078:Positron Emission Tomography Computed Tomography / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D012185:Retroperitoneal Fibrosis / Q000175:diagnosis* / Q000628:therapy*; D013012:Sorbitol / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: C531573:2-deoxy-2-fluorosorbitol; D013012:Sorbitol; D002097:C-Reactive Protein; D003404:Creatinine
keywords: Idiopathic retroperitoneal fibrosis; Positron emission tomography (PET); Renal insufficiency; Serum creatinine