Thoax CT Scan as Invasive Fungal Infection (IFI) Screening In Neutropenic Patients, a Prospective-Retrospective Experience of It Impact on Therapeutic Intervention.

Persistent fever in high risk neutropenic patients (HRNF) after day 5 of empiric treatment is a sign of high susceptibility for IFI with elevated morbidity and mortality. Diagnostic tools in this setting are inaccurate to determine the occurrence of IFI and most patients start with empiric antifungal agents. Drugs are usually associated with increasing costs and toxicity. It is challenging to establish the population of patients in whom in spite of persistent fever and neutropenia, avoidance of antifungal treatment is a reasonable strategy.

We have prospectively allocated 229 HRNF patients in different empiric antimicrobial regimens over a 4.5 year period. In a retrospective revision, there were 33 patients with persistent fever on day 5 of empirical antimicrobial treatment and no evident new infection episode or clinical impairment. In 28 patients, a thorax CT scan was performed as part of the evaluation of persistent fever. The clinical outcome was evaluated regarding the presence or absence of pulmonary infiltrates in the CT scans. Initial empiric antifungal treatment, transfusions, days in hospital, days with neutropenia, antimicrobial treatment, and days with fever were evaluated.

Nineteen patients (68%) of 28 presented with pulmonary infiltrates. All of them received antifungal treatment. In 9 patients with normal CT scan antifungal treatment was deferred. The difference of the decision in not giving antifungals according CT scans was highly significant (p <0,0001). Transfusions of red blood cells and platelets were significantly less in the group of normal scans (p 0,0004 and 0,005 respectively). Antimicrobial treatment, days in hospital and days with fever were not significantly different in both groups. There was one death in the normal scan group due to relapse. Mortality was not significantly different in both groups.

In HRNP, normal thorax CT scan changed the clinical decision in not starting antifungal treatment in spite of persistent fever. There was no difference in mortality with patients under antifungal treatment, allowing continuing with this strategy in more patients in the future.

No relevant conflicts of interest to declare.