Hae-jin Kim, Presenter: Nothing to Disclose

So Young Park, Abstract Co-Author: Nothing to Disclose

Ho Yun Lee MD, Abstract Co-Author: Nothing to Disclose

Kyung Soo Lee MD, PhD, Abstract Co-Author: Nothing to Disclose

Kyoungeun Shin, Abstract Co-Author: Nothing to Disclose

Jung Won Moon, Abstract Co-Author: Nothing to Disclose

Tae Sung Kim MD, Abstract Co-Author: Nothing to Disclose

Myung Jin Chung MD, Abstract Co-Author: Consultant, Samsung Electronics Co Ltd Patent agreement, General Electric Company

Chin A Yi MD, PhD, Abstract Co-Author: Nothing to Disclose

 Patients with hematological malignancies are at increased risk of potentially fatal infections as a consequence of treatment-induced neutropenia, and prompt identification and treatment is critical to achieve a good outcome. The frequency of particular computed tomography (CT) patterns and their associations with certain micro-organisms in immunocompromised hosts have been described. Moreover, the use of low-dose CT of the thorax has become a promising alternative to the chest radiography and high-resolution CT. We aimed to evaluate the efficacy of ultra low dose CT (ULDCT) to assess patients with neutropenic fever.

ULDCT scans were performed prospectively in 207 febrile neutropenic patients with hematological malignancy (effective doses: 0.65 ± 0.15 mSv). Three chest radiologists independently reviewed CT images, and recorded two most likely diagnoses among bacterial, fungal, Pneumocystis jirovecii (PJP), and viral pneumonia, with their confidence level. If pneumonia was detected by ULDCT, bronchoalveolar lavage was recommended. Evidence of pneumonia on follow-up chest images and micro-organisms detected during follow-up were regarded as documentation of pneumonia. Observer performance was compared using McNemar’s test and receiver operating characteristic (ROC) analysis, and interobserver agreements were determined using kappa coefficients.

 Of the 207 CT scans, 139 (67%) showed pneumonia and 68 were non-infectious cause or extrathoracic fever focus. Incidence of bacterial, fungal, PJP or CMV, and viral pneumonia were 48 (34.5%), 55 (39.6%), 5 (3.6%), and 42 (30.2%), respectively. More than two pathogens were confirmed in 11 patients (7.9 %). Sensitivity and area under the ROC curve in differentiating specific pneumonia were 71.7 %, 0.65 for reader 1, 63.3 %, 0.61 for reader 2, and 74.8 %, 0.62 for reader 3, respectively (all P values < .05). There were moderate to good agreement among three readers (k = 0.58 - 0.67).

 ULDCT provides rapid and reasonably accurate diagnostic information in febrile neutropenic patients at a very low radiation dose.

 ULDCT is a useful tool in the initial investigation of suspected pulmonary complication in neutropenic patients.

Kim, H, Park, S, Lee, H, Lee, K, Shin, K, Moon, J, Kim, T, Chung, M, Yi, C, The Value of the Ultra-low-Dose Chest Computed Tomography in Febrile Neutropenic Patients with Hematological Malignancies.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12028544.html