Chest low-dose computed tomography in neutropenic acute myeloid leukaemia patients

We aimed to compare chest low-dose computed tomography (LDCT) with chest radiography (CXR) in the assessment of febrile acute myeloid leukaemia neutropenic patients.

A prospective non-randomized study was carried out between 30 May, 2003 and 3 June, 2004 in consecutive neutropenic patients who required imaging of the thorax and were treated for acute myeloid leukaemia. Each patient had a baseline 2-view chest radiograph followed by LDCT. Both the CXR and the LDCT studies were blindly and independently reviewed by two chest radiologists.

Forty patients were enrolled: 24 male and 16 female, mean age 53.5 years (range 18-83) and an average neutrophil count of 0.78 x 10(9)/L. Patients had CXR within a mean of 40 min from the LDCT. Overall, 31 (77.5%) of 40 CXR were abnormal, whereas LDCT detected abnormalities in 38 (95%) of 40 patients. LDCT demonstrated three times the number of lung nodules as CXR and twice as many ground-glass opacities. Lung consolidation was detected similarly using both techniques, but LDCT demonstrated more extensive and multi-focal consolidation. The majority of nodules detected only on LDCT were subcentimetre in diameter. The additional information provided by LDCT led to an alteration in the clinical management of 11 (27.5%) of 40 patients.

LDCT is a useful tool in the initial investigation of suspected pulmonary complication in neutropenic patients. This is supported by the additional information it provides to the CXR with reduced radiation when compared to conventional CT.