¹⁸F-FDG-PET/CT in unexplained elevated inflammatory markers

Summary

The diagnostic strategy in patients with fever or inflammation of unknown origin remains a major clinical challenge. The aim of this study was to evaluate the role of ¹⁸F-FDG-PET/CT in patients with unexplained elevated C-reactive protein with or without fever. Contribution of ¹⁸F-FDG-PET/CT to the final diagnosis was evaluated. In addition we determined whether a differentiation between patients with or without fever is clinically reasonable. Patients, methods: We retrospectively analysed 72 consecutive patients with unexplained elevated C-reactive protein levels (above 8mg/l) that underwent ¹⁸F-FDG-PET/ CT in our facility between 10/2009 and 11/2012. ¹⁸F-FDG-PET/CT was considered a so-called diagnostic scan when results decisively led to a final diagnosis and adequate therapy with a response of symptoms was initiated due to the PET/CT result. Results: In 60/72 patients (83%) a final diagnosis was established. Diagnoses included infections (58%), non-infectious inflammatory diseases (29%) and malignancies (8%). ¹⁸F-FDG-PET/CT was true positive in 47 cases (65%) and the diagnostic scan in 29 patients (40%). Sensitivity of ¹⁸F-FDG-PET/CT was 81% and specificity was 86%. Diagnostics, final diagnoses, ¹⁸F-FDG-PET/CT results, SUVmax, C-reactive protein levels and the diagnostic scan did not differ significantly between patients with fever and patients without fever. Conclusion: ¹⁸F-FDG-PET/CT is a useful method in the diagnostic workup of patients with inflammation of unknown origin. In our series there was no significant difference between patients with or without fever. Regarding ¹⁸F-FDG-PET/CT-imaging inflammation of unknown origin and unexplained fever can be joined to one entity.

Zusammenfassung

Die diagnostische Strategie bei Patienten mit Entzündungen unklarer Genese stellt eine große klinische Herausforderung dar. Das Ziel dieser Studie war die Evaluation der Rolle der ¹⁸F-FDG-PET/CT bei Patienten mit unklarer Erhöhung des C-reaktiven Proteins mit und ohne Fieber. Der Beitrag der ¹⁸F-FDG-PET/CT zur Enddiagnose sowie Unterschiede zwischen Patienten mit und ohne Fieber wurden untersucht. Patienten, Methoden: In dieser Arbeit wurden 72 Patienten mit unklarer Erhöhung des C-reaktiven Proteins (> 8mg / l), die zwischen 10/2009 und 11/2012 in unserer Abteilung mittels ¹⁸F-FDG-PET/CT untersucht wurden, retrospektiv ausgewertet. Die ¹⁸F-FDG-PET/CT wurde zudem als sogenannter „Diagnostischer Scan“ gewertet, wenn das ¹⁸F-FDG-PET/CT-Ergebnis entscheidend zur Enddiagnose beitrug und daraufhin eine adäquate Therapie initiiert wurde, welche zu einer Normalisierung des C-reaktiven Proteins führte. Ergebnisse: Bei 60 von 72 (82%) Patienten wurde eine endgültige Diagnose gestellt. Diagnosen beinhalteten Infektionen (58%), rheumatoide (29%) und maligne Erkrankungen (8%). Die ¹⁸F-FDG-PET/CT war in 47 Fällen (65%) richtig positiv und in 29 Fällen (40%) der Diagnostische Scan. Die Sensitivität der ¹⁸F-FDG-PET/CT betrug 81% und die Spezifität 86%. Diagnostik, Enddiagnosen, SUVmax, CRP und der Diagnostische Scan zeigten keine signifikanten Unterschiede zwischen Patienten mit und ohne Fieber. Schlussfolgerung: Die ¹⁸F-FDG-PET/CT ist eine wichtige Methode in der Diagnostik von Patienten mit erhöhten Entzündungsparametern unklarer Genese. In unserer Studie zeigte sich kein signifikanter Unterschied zwischen Patienten mit und ohne Fieber, sodass man bezüglich der ¹⁸F-FDG-PET/CT-Bildgebung unerklärtes Fieber und Entzündungen unklarer Genese zu einer Entität zusammenfassen kann.

Keywords

Fever - inflammation of unknown origin - C-reac tive protein - ¹⁸F-FDG-PET/CT

Schlüsselwörter

Fieber - Entzündung unklarer Genese - C-reaktives Protein - ¹⁸F-FDG-PET/CT

• References

• 1 Avril N. GLUT1 expression in tissue and ¹⁸F-FDG uptake. J Nucl Med 2004; 45: 930-932.
• 2 Balink H, Verberne HJ, Bennink RJ. et al. A Rationale for the use of F18-FDG PET/CT in fever and inflammation of unknown origin. Int J Mol Imaging. 2012: 12 pages
• 3 Balink H, Bennink RJ, Veeger N. et al. Diagnostic utility of ¹⁸F-FDG PET/CT in inflammation of unknown origin. Clin Nucl Med 2014; 39: 419-425.
• 4 Bhargava P, Kumar R, Zhuang H. et al. Catheter-related focal FDG activity on whole body PET imaging. Clin Nucl Med 2004; 29: 238-242.
• 5 Clyne B, Olshaker JS. The C-reactive protein. J Emerg Med 1999; 6: 1019-1025.
• 6 Durack DT, Street AC. Fever of unknown origin - reexamined and redefined. Curr Clin Top Infect Dis 1991; 11: 35-51.
• 7 Federici L, Blondet C, Imperiale A. et al. Value of ¹⁸F-FDG-PET/CT in patients with fever of unknown origin and unexplained prolonged inflammatory syndrome: a single centre analysis experience. Int J Clin Pract 2010; 1: 55-60.
• 8 Gafter-Gvili A, Raibman S, Grossman A. et al. [¹⁸F]FDG-PET/CT for the diagnosis of patients with fever of unknown origin. QJM 2015; 4: 289-98.
• 9 Hao R, Yuan L, Kan Y. et al. Diagnostic performance of ¹⁸F-FDG PET/CT in patients with fever of unknown origin: a meta-analysis. Nucl Med Comm 2013; 7: 682-688.
• 10 Jaruskova M, Belohlavek O. Role of FDG-PET and PET/CT in the diagnosis of prolonged febrile states. Eur J Nucl Med Mol Imaging 2006; 33: 913-918.
• 11 Kei PL, Kok TY, Padhy AK. et al. [¹⁸F] FDG PET/CT in patients with fever of unknown origin: a local experience. Nucl Med Commun 2010; 31: 788-792.
• 12 Meller J, Sahlmann CO, Scheel AK. ¹⁸F-FDG PET and PET/CT in fever of unknown origin. J Nucl Med 2007; 48: 35-45.
• 13 Meller J, Sahlmann CO, Lehmann K. et al. ¹⁸F-FDG hybrid camera PET in patients with postoperative fever. Nuklearmedizin 2002; 41: 22-29.
• 14 Moragas M, Coza--r MP, Buxeda M. et al. Estudio de pacientes con síndrome febril prolongado con ¹⁸F-FDG PET-TC. Radiologia 2015; 57: 489-495.
• 15 Mourad O, Palda V, Detsky AS. A comprehensive evidence-based approach to fever of unknown origin. Arch Intern Med 2003; 163: 545-551.
• 16 Norman DC. Fever in the elderly. Clin Infect Dis 2000; 31: 148-151.
• 17 Okamura K. The assessment of biologic treatment in patients with rheumatoid arthritis using FDG-PET/CT. Rheumatology (Oxford) 2012; 8: 1484-1491.
• 18 Pedersen TI, Roed C, Knudsen LS. et al. Fever of unknown origin: a retrospective study of 52 cases with evaluation of the diagnostic utility of FDG-PET/CT. Scand J Infect Dis 2012; 44: 18-23.
• 19 Pelosi E, Skanjeti A, Penna D, Arena V. Role of integrated PET/CT with [¹⁸F]-FDG in the management of patients with fever of unknown origin: a single-centre experience. La Radiologia Medica 2011; 5: 809-820.
• 20 Perrin AE, Goichot B, Andrès E. et al. Evolution et pronostic à long terme des syndromes inflammatoires biologiques persistants inexpliqués. La Revue de Médecine Interne 2002; 8: 683-689.
• 21 Petersdorf RG, Beeson PB. Fever of unexplained origin: report on 100 cases. Medicine 1961; 4: 1-30.
• 22 Sheng J, Sheng Z, Shen X. et al. Diagnostic value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in patients with fever of unknown origin. Eur J Intern Med 2011; 22: 112-116.
• 23 Soussan M, Nicolas P, Schramm C. et al. Management of large-vessel vasculitis with FDG-PET: a systematic literature review and meta-analysis. Medicine 2015; 14: e622.
• 24 Surti S, Kuhn A, Werner ME. et al. Performance of Philips Gemini TF PET/CT scanner with special consideration for its time-of-flight imaging capabilities. J Nucl Med 2007; 48: 471-480.
• 25 Termaat MF, Raijmaker PGHM, Scholten HJ. et al. The accuracy of diagnostic imaging for the assessment of chronic osteomyelitis: a systematic review and meta-analysis. J Bone Joint Surg 2005; 11: 2464-2471.
• 26 Tezuka D. Role of FDG PET-CT in Takayasu arteritis: Sensitive detection of recurrences. J Am Coll Cardiol Imaging 2012; 5: 422-429.
• 27 Vanderschueren S, Knockaert D. Tackling fever and inflammation of unknown origin: the do‘s and don‘ts. Acta Clin Belg 2014; 6: 412-417.
• 28 Vanderschueren S, Del Biondo E, Ruttens D. et al. Inflammation of unknown origin versus fever of unknown origin: two of a kind. Eur J Intern Med 2009; 4: 415-418.
• 29 Walter M. A. The value of [¹⁸F] FDG-PET in the diagnosis of large-vessel vasculitis and the assessment of activity and extent of disease. Eur J Nucl Med Mol Imaging 2004; 31: 627-634.