Learning objectives
To illustrate the management of febrile neutropenic onco-haematologic patients with high risk of pulmonary Invasive Mould Disease (IMD) with a 2-steps CT protocol:
-step 1: chest low-dose high-resolution computed tomography (LDCT) for screening and
-step 2: CT pulmonary angiography (CTPA) for characterization of pulmonary lesions.
Background
IMD are frequent pulmonary infective complications with severe prognosis in neutropenic febrile patients and early detection is imperative,
because the outcome depends strongly on prompt use of appropriate antifungals.
In neutropenic patients IMD usually occurs after inhalation of conidia of filamentous fungi such as Aspergillus; fungal spores pass through the bronchial tree and reach the alveoli,
where germinate and in the form of fungal hyphae,
due to the absence of neutrophil cells,
invade first the broncho-alveolar and then the vascular structures causing endothelial damage and...
Findings and procedure details
A “proven” diagnosis of IMD requires transbronchial and/or lung biopsy for culture or histological documentation of infection,
which may be unfeasible in patients with severe thrombocytopenia.
A “probable” diagnosis of IMD requires a mycological evidence,
which is based on culture tests (limited by low sensitivity and long waiting times for results) and on laboratory tests,
such as the serum galactomannan (GM) test specific for aspergillosis,
which also has diagnostic limitations,
including lower sensitivity in the setting of antifungal prophylaxis and false-positive results in patients receiving...
Conclusion
In neutropenic febrile onco-hematological patients,
early HRCT can be a screening tool (step 1) for the detection of pulmonary lesions which should be better characterized trough CTPA (step 2) (Figure 9).
HRCT is also routinely performed during follow-up,
but in case of appearance of new lesions should be performed CTPA for their more accurate characterization.
A low-dose CT protocol is recommended to lower the radiologic burden.
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