[Epidemiology and interventional treatment strategies of infectious complications after allogenic stem-cell transplantation]

Sequential low-dose CT thorax scans to determine invasive pulmonary fungal infection incidence after allogeneic hematopoietic cell transplantation

Invasive fungal disease (IFD) during neutropenia goes along with a high mortality for patients after allogeneic hematopoietic cell transplantation (alloHCT). Low-dose computed tomography (CT) thorax shows good sensitivity for the diagnosis of IFD with low radiation exposure. The aim of our study was to evaluate sequential CT thorax scans at two time points as a new reliable method to detect IFD during neutropenia after alloHCT. We performed a retrospective single-center observational study in 265/354 screened patients admitted for alloHCT from June 2015 to August 2019. All were examined by a low-dose CT thorax scan at admission (CT t₀) and after stable neutrophil recovery (CT t₁) to determine the incidences of IFD. Furthermore, antifungal prophylaxis medications were recorded and cohorts were analyzed for statistical differences in IFD incidence using the sequential CT scans. In addition, IFD cases were classified according to EORTC 2008. At CT t₀ in 9.6% of the patients, an IFD was detected and antifungal therapy initiated. The cumulative incidence of IFD in CT t₁ in our department was 14%. The use of Aspergillus-effective prophylaxis through voriconazole or posaconazole decreased CT thorax t₁ suggesting IFD is statistically significant compared to prophylaxis with fluconazole (5.6% asp-azol group vs 16.3% fluconazole group, p = 0.048). In 86%, CT t₁ was negative for IFD. Low-dose sequential CT thorax scans are a valuable tool to detect pulmonary IFDs and guide antifungal prophylaxis and therapies. Furthermore, a negative CT t₁ scan shows a benefit by allowing discontinuation of antifungal medication sparing patients from drug interactions and side effects.

BK virus-induced nephritis and cystitis after matched unrelated donor stem cell transplantation: A case report

Currently, there is no standard therapy for a BK virus infection of the urogenital tract in immunocompromised, stem cell transplanted patients, so that early diagnosis and introduction of supportive measures have the highest response rates to date.

Diagnostic Radiology in Hematological Patients with Febrile Neutropenia

Radiologists have a special role in the management of neutropenic patients. The appropriate investigational technique, specific differential diagnoses, and particular risks of these patients need to be understood by referring physicians as well as by radiologists. Thus, communication and cooperation, also including other clinical disciplines such as pulmonology, are required.

Early detection of an infectious focus is the major goal in febrile neutropenic patients. As pneumonia is the most common focus, chest imaging is a special radiological task. The sensitivity of chest x-ray, especially in supine position, is low. Therefore, the very sensitive thin-section multislice CT became a gold standard in neutropenic hosts and might be cost effective in comparison to antibiotic treatment. CT-based localization can be used to guide invasive procedures in order to obtain samples for microbiological workup. Furthermore, the radiological characterization of infiltrates gives a first and rapid hint to discriminate between infectious (viral, typical bacterial, atypical bacterial, fungal) and noninfectious etiologies. Radiological follow-up has to take into account aspects according to disease, immune recovery, and treatment modalities. Due to a high incidence of fungal-related lung infiltrates, interpretation of follow-up findings must include further parameters besides lesion size.

Apart from the lungs, also other organ systems such as the brain, liver, and paranasal sinuses need attention and are to be imaged with the appropriate technique.

Pneumonia

Most patients suffering from community acquired pneumonia do not appear at a radiology department since diagnosis is made on a clinical basis. In severe or unclear situations, a chest X-ray is done and analysis is frequently done by interns. Radiologists frequently see those patients that suffer from recurrent, nosocomial pneumonia, or an additional predisposing disease. The appropriate investigational technique, frequently targeted differential diagnosis, and the special needs of these patients need to be understood by radiologists. Early detection of a focus of infection is the major goal in immunocompromised patients. As pneumonia is the most common focus, chest imaging is to be done at the beginning. The sensitivity of chest X-rays, especially in the supine position, is known to be low. Therefore the very sensitive high-resolution CT (HRCT) became the gold standard in neutropenic hosts and is widely replaced by thin-section multi-detector-row-CT (MDCT). Underlying diseases such as pulmonary embolism or bronchial carcinoma might also be depicted. Furthermore, the costs of CT are low in comparison to antibiotics. The infiltrate needs to be localised, so that a physician can utilise this information as a guidance for invasive procedures for further microbiological work-up. The radiological characterisation of infiltrates gives a first and rapid hint to differentiate between different sorts of infectious (typical bacterial, atypical bacterial, fungal) and non-infectious aetiologies. Follow-up investigations need careful interpretation according to disease and concomitant treatment. Temporary exclusion of infectious involvement of the lung with high accuracy is, besides of pneumonia management, a hot topic for clinicians.

Pneumonia in neutropenic patients

Radiologists have a special role in the management of neutropenic patients. The appropriate investigational technique, frequently targeted differential diagnosis, and the special needs of these patients, need to be understood. Early detection of a focus is the major goal in febrile neutropenic patients. As pneumonia is the most common focus, chest imaging is a special radiological task. The sensitivity of chest X-ray, especially in supine position, is known to be low; therefore, the very sensitive high-resolution CT (HRCT) became gold standard in neutropenic hosts and will probably be replaced by thin-section multislice CT (MSCT) in the near future. Costs of high-resolution CT are low in comparison to antibiotics. An infiltrate needs to be localised, so that a physician can utilise this information as a guidance for invasive procedures for further microbiological work-up. The radiological characterisation of infiltrates gives a first and rapid hint to differentiate between different sorts of infectious (typical bacterial, atypical bacterial, fungal) and non-infectious aetiologies. Follow-up investigations need careful interpretation according to disease and concomitant treatment. Due to an increased incidence of fungal infiltrates even with appropriate therapy, follow-up of an infiltrate must use further parameters in addition to lesion size. Temporary exclusion of infectious involvement of the lung with high accuracy remains of special interest for clinicians.