20-year Review: MRI Reveals Prognostic Data in Invasive Fungal Disease

Imaging and therapy for acute invasive fungal rhinosinusitis (AIFRS) have advanced in the last 20 years, although the ocular exenteration and mortality rates remain high, at approximately 20% and 50%, respectively. This is largely due to the condition’s rarity and aggressiveness. While computed tomography (CT) offers the quickest look at the sinonasal region, magnetic resonance imaging (MRI) has shown sensitivity for early detection, and may deliver predictive data on visual outcome and survival, according to a study published in Ophthalmology. 

Currently, AIFRS care is more well-defined in cases of ascomycota infection; and research shows that older age, neutropenia, intracranial involvement, and mucoromycotina often lead to poorer outcomes. Of the 78 patients included in the current record review, mean age 51.1±22.2 years; there were 93 cases — 63 unilateral and 15 bilateral, and mucoromycotina affected 56%. Workups took place during January 2000 to February 2020. Investigators calculated predictive factors based on initial and pre-intervention MRI parameters.

The analysis found the rate for visual survival was 26% — with blindness or best-corrected visual acuity (VA) of worse than 20/400 from exenteration or disease at 74% — and mortality rate from infection was 39%. Median follow-up time was 12 months. MRI demonstrated independent predictors for poor VA outcome were involvement of the cerebral arteries (RR =1.8, P <.001) and disease occurring at the orbital apex (RR =2.0, P =.026). Prognostic findings for mortality comprised 3 regions of involvement; intracranial space (HR =3.5, P =.006), nasolacrimal drainage structures (HR =5.0, P =.008), and facial soft tissues (HR =4.9, P =.017). However, if orbital soft tissue was involved, mortality rate decreased (HR =0.3, P =.001).

Investigators speculate that orbital soft tissue involvement is protective due to earlier palpable signs, such as proptosis or vision loss, spurring prompt workup. Infiltration of the other extra-sinonasal regions may hide infection or give inconclusive clinical tests.

Cerebral artery or orbital apex involvement revealed twice the risk for poor VA. Disease at the orbital apex may signal ischemic or compressive optic neuropathy. Other impacts from invasion of the orbital region include exposure keratopathy from proptosis, or nerve-related blinking disorders. Involvement of the cerebral artery may indicate problems at the ophthalmic artery.

Fungal organisms are angio-invasive and spread to neighboring structures, so extra-sinonasal presence predicted higher mortality, suggesting presentation at later disease stages. Further, when the nasolacrimal drainage system is involved, there may be a point of entry to the orbit — of 8 patients with inflammatory changes or loss of contrast enhancement on imaging, 5 died. Disease in facial soft tissues occurred in 81% of participants — many of these cases revealed spread to the infratemporal or pterygopalatine fossa, with prior reports showing this may increase risk for intracranial infiltration.

Patients were treated at a single, California academic tertiary center. A retrospective design limited this study, as well as unmasked chart reviewers and neuro-radiologists. Time from presentation to imaging varied. A wider, pooled analysis of multiple centers may allow creation of imaging rubric for better assessment. This is the largest investigation yet to examine predictors based on initial MRI for those with AIFRS, a life-threatening illness.

Disclosures: One study author declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Reference

Idowu OO, Soderlund KA, Laguna B, et al. Magnetic resonance imaging prognostic findings for visual and mortality outcomes in acute invasive fungal rhinosinusitis. Ophthalmol. Published online June 26, 2022. doi:10.1016/j.ophtha.2022.06.020