Could SUVmax be an auxiliary parameter in the clinical management of pulmonary hydatid disease?

'No cyst, no echinococcosis': a scoping review update on the diagnosis of cystic echinococcosis after the issue of the WHO-IWGE Expert Consensus and current perspectives

PURPOSE OF REVIEW

In 2010, the WHO-Informal Working Group on Echinococcosis (IWGE) published an Expert Consensus on the diagnosis and treatment of echinococcal infections. We provide an update on the diagnosis of cystic echinococcosis through a scoping review of the literature published after the release of the WHO-IWGE document.

RECENT FINDINGS

Ultrasound accurately and reliably depicts the pathognomonic signs of cystic echinococcosis (CE) stages compared with other imaging techniques. Among these, T2-wighted MRI is to be preferred to computed tomography, which has poor performance for the etiological diagnosis of CE. A negative serology cannot exclude the diagnosis of CE, while a positive serology, applied after the visualization of a CE-compatible lesion, may confirm a CE diagnosis. Serology alone must not be used to define 'CE' nor as 'screening' tool for infection. Other imaging and laboratory techniques did not show clinically applicable performances.

SUMMARY

In the absence of a focal lesion compatible with a CE cyst, no diagnosis of CE should be attempted. There is urgent need to achieve univocal CE case definitions and consensus diagnostic algorithm, as well as standardization of diagnostic methods and issue of a Target Product Profile of CE diagnostics, as advocated by the WHO in the 2021-2030 roadmap for neglected tropical diseases (NTDs).

Usefulness of the FDG PET/CT in the management of cystic echinococcosis: A pilot study

OBJECTIVES

Cystic echinococcosis is a zoonotic disease caused by the cestode Echinococcus granulosus. The activity of the cysts is assessed through the WHO-IWGE standardized classification based on ultrasound features. However, viability of the cysts is not always concordant with the activity assessed by ultrasound. The aim of the present study is to describe the metabolic activity of cysts in patients with cystic echinococcosis through FDG-PET.

METHODS

Prospective observational study where adult patients diagnosed of cystic echinococcosis were offered to undergo FDG PET/CT before treatment onset. Demographic, clinical, radiological, and histopathological information was collected from all patients.

RESULTS

Sixteen patients were included, 50% were male, and age ranged from 18 to 85 years. Most of the patients had liver involvement, and all patients had CE3, CE4 or CE5 stage of the WHO-IWGE classification. Only one patient (CE5) had an increased ¹⁸F-FDG uptake of the cyst in the FDG PET/CT. From the 5 patients who underwent surgical treatment, only one showed signs of viability of the cyst: a patient with CE5 with no increased ¹⁸F-FDG uptake of the cyst.

CONCLUSION

In our pilot study, we did not find the correlation between the FDG PET/CT imaging and the cystic echinococcosis cyst bioactivity.