Pulmonary Mucormycosis: Risk Factors, Radiologic Findings, and Pathologic Correlation.

Pulmonary mucormycosis (PM) is an uncommon fungal infection most often seen in immunocompromised patients. The fungus grows on decaying food, soil, and animal excrement. Patients usually become infected by inhalation of spores. The most common risk factors include diabetes mellitus, hematologic malignancy, and solid organ or stem cell transplant. PM can have a nonspecific appearance at imaging. For example, early imaging may show peribronchial ground-glass opacity. Later, the disease progresses to consolidation, nodules, or masses. Because patients are usually immunocompromised, the differential diagnosis often includes invasive pulmonary aspergillosis (IPA). Various radiologic findings suggestive of PM have been identified to help differentiate it from IPA. For example, the reverse halo sign is more closely associated with PM than with IPA. The reverse halo sign is an area of ground-glass opacity surrounded by a rim of consolidation. In addition, the presence of pleural effusions and more than 10 nodules is more suggestive of PM than it is of IPA. PM can progress rapidly in neutropenic patients. Identification of the hyphae in tissue by using endobronchial or percutaneous sampling can allow differentiation from IPA and help confirm the diagnosis of mucormycosis. Because of the high mortality rate associated with PM, early identification of the disease is critical for an improved likelihood of survival. A multimodality treatment approach with antifungal agents and surgical débridement has been shown to improve outcomes. The authors review the risk factors for PM, describe its imaging appearance and disease process, and describe the treatment of the disease. ©RSNA, 2020.

Community-Acquired Pneumonia Visualized on CT Scans but Not Chest Radiographs: Pathogens, Severity, and Clinical Outcomes.

BACKGROUND: The clinical significance of pneumonia visualized on CT scan in the setting of a normal chest radiograph is uncertain. METHODS: In a multicenter prospective surveillance study of adults hospitalized with community-acquired pneumonia (CAP), we compared the presenting clinical features, pathogens present, and outcomes of patients with pneumonia visualized on a CT scan but not on a concurrent chest radiograph (CT-only pneumonia) and those with pneumonia visualized on a chest radiograph. All patients underwent chest radiography; the decision to obtain CT imaging was determined by the treating clinicians. Chest radiographs and CT images were interpreted by study-dedicated thoracic radiologists blinded to the clinical data. RESULTS: The study population included 2,251 adults with CAP; 2,185 patients (97%) had pneumonia visualized on chest radiography, whereas 66 patients (3%) had pneumonia visualized on CT scan but not on concurrent chest radiography. Overall, these patients with CT-only pneumonia had a clinical profile similar to those with pneumonia visualized on chest radiography, including comorbidities, vital signs, hospital length of stay, prevalence of viral (30% vs 26%) and bacterial (12% vs 14%) pathogens, ICU admission (23% vs 21%), use of mechanical ventilation (6% vs 5%), septic shock (5% vs 4%), and inhospital mortality (0 vs 2%). CONCLUSIONS: Adults hospitalized with CAP who had radiological evidence of pneumonia on CT scan but not on concurrent chest radiograph had pathogens, disease severity, and outcomes similar to patients who had signs of pneumonia on chest radiography. These findings support using the same management principles for patients with CT-only pneumonia and those with pneumonia seen on chest radiography.

Interval lung cancer after a negative CT screening examination: CT findings and outcomes in National Lung Screening Trial participants.

OBJECTIVES: This study retrospectively analyses the screening CT examinations and outcomes of the National Lung Screening Trial (NLST) participants who had interval lung cancer diagnosed within 1 year after a negative CT screen and before the next annual screen. METHODS: The screening CTs of all 44 participants diagnosed with interval lung cancer (cases) were matched with negative CT screens of participants who did not develop lung cancer (controls). A majority consensus process was used to classify each CT screen as positive or negative according to the NLST criteria and to estimate the likelihood that any abnormalities detected retrospectively were due to lung cancer. RESULTS: By retrospective review, 40/44 cases (91%) and 17/44 controls (39%) met the NLST criteria for a positive screen (P < 0.001). Cases had higher estimated likelihood of lung cancer (P < 0.001). Abnormalities included pulmonary nodules ≥4 mm (n = 16), mediastinal (n = 8) and hilar (n = 6) masses, and bronchial lesions (n = 6). Cancers were stage III or IV at diagnosis in 32/44 cases (73%); 37/44 patients (84%) died of lung cancer, compared to 225/649 (35%) for all screen-detected cancers (P < 0.0001). CONCLUSION: Most cases met the NLST criteria for a positive screen. Awareness of missed abnormalities and interpretation errors may aid lung cancer identification in CT screening. KEY POINTS: • Lung cancer within a year of a negative CT screen was rare. • Abnormalities likely due to lung cancer were identified retrospectively in most patients. • Awareness of error types may help identify lung cancer sooner.

Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults.

BACKGROUND: Community-acquired pneumonia is a leading infectious cause of hospitalization and death among U.S. adults. Incidence estimates of pneumonia confirmed radiographically and with the use of current laboratory diagnostic tests are needed. METHODS: We conducted active population-based surveillance for community-acquired pneumonia requiring hospitalization among adults 18 years of age or older in five hospitals in Chicago and Nashville. Patients with recent hospitalization or severe immunosuppression were excluded. Blood, urine, and respiratory specimens were systematically collected for culture, serologic testing, antigen detection, and molecular diagnostic testing. Study radiologists independently reviewed chest radiographs. We calculated population-based incidence rates of community-acquired pneumonia requiring hospitalization according to age and pathogen. RESULTS: From January 2010 through June 2012, we enrolled 2488 of 3634 eligible adults (68%). Among 2320 adults with radiographic evidence of pneumonia (93%), the median age of the patients was 57 years (interquartile range, 46 to 71); 498 patients (21%) required intensive care, and 52 (2%) died. Among 2259 patients who had radiographic evidence of pneumonia and specimens available for both bacterial and viral testing, a pathogen was detected in 853 (38%): one or more viruses in 530 (23%), bacteria in 247 (11%), bacterial and viral pathogens in 59 (3%), and a fungal or mycobacterial pathogen in 17 (1%). The most common pathogens were human rhinovirus (in 9% of patients), influenza virus (in 6%), and Streptococcus pneumoniae (in 5%). The annual incidence of pneumonia was 24.8 cases (95% confidence interval, 23.5 to 26.1) per 10,000 adults, with the highest rates among adults 65 to 79 years of age (63.0 cases per 10,000 adults) and those 80 years of age or older (164.3 cases per 10,000 adults). For each pathogen, the incidence increased with age. CONCLUSIONS: The incidence of community-acquired pneumonia requiring hospitalization was highest among the oldest adults. Despite current diagnostic tests, no pathogen was detected in the majority of patients. Respiratory viruses were detected more frequently than bacteria. (Funded by the Influenza Division of the National Center for Immunizations and Respiratory Diseases.).

Phase I/II Study of HSP90 Inhibitor AUY922 and Erlotinib for EGFR-Mutant Lung Cancer With Acquired Resistance to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors.

PURPOSE: AUY922 is an HSP90 inhibitor that causes degradation of HSP chaperones and their client proteins, including epidermal growth factor receptor. We conducted a phase I/II trial to evaluate AUY922 and erlotinib for patients with EGFR-mutant lung cancer and disease progression during erlotinib treatment. PATIENTS AND METHODS: All patients had developed acquired resistance after treatment with erlotinib and underwent repeat tumor biopsies before study entry to assess for EGFR T790M. In phase I, 18 patients were treated with AUY922 intravenously once per week and erlotinib once per day in 28-day cycles using a 3 + 3 dose-escalation design. In phase II, 19 additional patients were treated at the maximum-tolerated dose. The primary end point of the phase II trial was complete plus partial response rate. RESULTS: In phase I (n = 18), three patients were treated in each cohort, except the highest-dose cohort (AUY922 70 mg and erlotinib 150 mg), which expanded to six patients because of a dose-limiting toxicity (ie, junctional cardiac rhythm). Common drug-related adverse events were diarrhea, skin rash, hyperglycemia, and night blindness. All patients treated at maximum-tolerated dose (n = 25) were evaluable for response. The partial response rate was 16% (four of 25 patients; 95% CI, 5% to 36%) and was independent of tumor T790M status. CONCLUSION: Partial responses were observed, but the duration of treatment with AUY922 and erlotinib was limited by toxicities, especially night blindness. This phase II study of AUY922 and erlotinib did not meet its primary end point.

Effect of radiation dose and iterative reconstruction on lung lesion conspicuity at MDCT: does one size fit all?

OBJECTIVE: To evaluate the effect of different acquisition parameters and reconstruction algorithms in lung lesions conspicuity in chest MDCT. METHODS: An anthropomorphic chest phantom containing 6 models of lung disease (ground glass opacity, bronchial polyp, solid nodule, ground glass nodule, emphysema and tree-in-bud) was scanned using 80, 100 and 120 kVp, with fixed mAs ranging from 10 to 110. The scans were reconstructed using filtered back projection (FBP) and iterative reconstruction (IR) algorithms. Three blinded thoracic radiologists reviewed the images and scored lesions conspicuity and overall image quality. Image noise and radiation dose parameters were recorded. RESULTS: All acquisitions with 120 kVp received a score of 3 (acceptable) or higher for overall image quality. There was no significant difference between IR and FBP within each setting for overall image quality (p>0.05), even though image noise was significantly lower using IR (p<0.0001). When comparing specific lower radiation acquisition parameters 100 kVp/10 mAs [Effective Dose (ED): 0.238 mSv] vs 120 kVp/10 mAs (ED: 0.406 mSv) vs 80 kVp/40 mAs (ED: 0.434 mSv), we observed significant difference in lesions conspicuity (p<0.02), as well as significant difference in overall image quality, independent of the reconstruction algorithm (p<0.02), with higher scores on the 120 kV/10 mAs setting. Tree-in-bud pattern, ground glass nodule and ground glass opacity required lower radiation doses to get a diagnostic score using IR when compared to FBP. CONCLUSION: Designing protocols for specific lung pathologies using lower dose acquisition parameters is feasible, and by applying iterative reconstruction, radiologists may have better diagnostic confidence to evaluate some lesions in very low dose settings, preserving acceptable image quality.

Phase II study of pemetrexed and carboplatin plus bevacizumab with maintenance pemetrexed and bevacizumab as first-line therapy for nonsquamous non-small-cell lung cancer.

PURPOSE: This study evaluated the efficacy and safety of pemetrexed, carboplatin, and bevacizumab followed by maintenance pemetrexed and bevacizumab in patients with chemotherapy-naive stage IIIB (effusion) or stage IV nonsquamous non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Patients received pemetrexed 500 mg/m(2), carboplatin area under the concentration-time curve of 6, and bevacizumab 15 mg/kg every 3 weeks for six cycles. For patients with response or stable disease, pemetrexed and bevacizumab were continued until disease progression or unacceptable toxicity. RESULTS: Fifty patients were enrolled and received treatment. The median follow-up was 13.0 months, and the median number of treatment cycles was seven (range, one to 51). Thirty patients (60%) completed > or = six treatment cycles, and nine (18%) completed > or = 18 treatment cycles. Among the 49 patients assessable for response, the objective response rate was 55% (95% CI, 41% to 69%). Median progression-free and overall survival rates were 7.8 months (95% CI, 5.2 to 11.5 months) and 14.1 months (95% CI, 10.8 to 19.6 months), respectively. Grade 3/4 hematologic toxicity was modest-anemia (6%; 0), neutropenia (4%; 0), and thrombocytopenia (0; 8%). Grade 3/4 nonhematologic toxicities were proteinuria (2%; 0), venous thrombosis (4%; 2%), arterial thrombosis (2%; 0), fatigue (8%; 0), infection (8%; 2%), nephrotoxicity (2%; 0), and diverticulitis (6%; 2%). There were no grade 3 or greater hemorrhagic events or hypertension cases. CONCLUSION: This regimen, involving a maintenance component, was associated with acceptable toxicity and relatively long survival in patients with advanced nonsquamous NSCLC. These results justify a phase III comparison against the standard-of-care in this patient population.

Proximal pulmonary arterial and intrapulmonary radiologic features of Eisenmenger syndrome and primary pulmonary hypertension.

Extrapulmonary and intrapulmonary radiologic features of Eisenmenger syndrome and primary pulmonary hypertension (PPH) and the clinical expressions that coincide with the radiologic features of these 2 forms of pulmonary hypertension have not previously been characterized. Computed tomography (CT) and pulmonary CT angiography (CTA) utilized GE High Speed Advantage or Siemens Evolution electron beam tomographic (EBT) scanners in 31 patients with cyanotic pulmonary vascular disease (PVD) (group A: 12 men and 19 women; mean age 38 +/- 4 years) and in 13 women with PPH-acyanotic PVD (group B: mean age 30 +/- 3 years). Ten group A and 3 group B patients underwent imaging twice, yielding 57 studies. Group A patients' extrapulmonary radiologic features included proximal pulmonary arteries that were consistently enlarged, and were aneurysmal in 13%, causing bronchial compression and atelectasis. Thromboses were uniformly present and mild in 71% and moderate to massive in 29% of patients. Massive proximal thromboses caused asphyxic death and augmented right-to-left shunts by increasing flow resistance. Mild to extensive mural calcific deposits occurred in 26% of patients. Intrapulmonary radiologic features included intrapulmonary embolic infarction, intrapulmonary hemorrhage, bronchial/systemic arterial collaterals, and neovascularity. Group B patients' extrapulmonary radiologic features included proximal pulmonary arteries that were consistently enlarged but not aneurysmal and devoid of thromboses. Mild to extensive mural calcific deposits occurred in 23% of these patients. Intrapulmonary radiologic features were confined to mosaic attenuation and bronchial/systemic collaterals.