F-18 Fluorodeoxyglucose PET/CT as a Diagnostic Tool in Orbital Inflammatory Disorders

ABSTRACT

Purpose

To assess the usefulness of FDG-PET/CT as a potential diagnostic tool for detecting underlying systemic diseases (SD) in patients with orbital inflammatory disorders (OID).

Methods

All consecutive patients managed for new-onset OID between 2011 and 2018 in a tertiary referral center, who underwent FDG-PET/CT as part of the etiological diagnostic workup were evaluated. To quantify the incremental value of FDG-PET/CT over standard diagnostic workup, the Net Reclassification Index (NRI) and Integrated Discrimination Index (IDI) were used.

Results

Among the 22 patients enrolled, 11 (50%) had a positive FDG-PET/CT. After clinicobiological evaluation, FDG-PET/CT correctly reclassified 4(29%) of 14 patients with SD (p = .04) and 1(13%) of 8 with idiopathic orbital inflammation syndrome (p = .32). NRI and IDI were 0.41 ± 0.17 (p = .03) and 0.38 ± 0.08 (p < .001), respectively. FDG-PET/CT successfully detected asymptomatic lesions in all (n = 4) patients with lymphoma.

Conclusion

FDG-PET/CT enabled accurate reclassification of more than one-quarter of patients with SD, especially extraorbital lymphomas.

KEYWORDS:

• Adnexal orbital lymphoma
• FDG-PET/CT
• idiopathic orbital inflammatory syndrome
• IgG4-related ophthalmic disease
• inflammatory orbital pseudotumor

Declaration of Interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.