[Management of solid pulmonary nodules]

LIONS PREY: A New Logistic Scoring System for the Prediction of Malignant Pulmonary Nodules

OBJECTIVES

Classifying radiologic pulmonary lesions as malignant is challenging. Scoring systems like the Mayo model lack precision in predicting the probability of malignancy. We developed the logistic scoring system 'LIONS PREY' (Lung lesION Score PREdicts malignancY), which is superior to existing models in its precision in determining the likelihood of malignancy.

METHODS

We evaluated all patients that were presented to our multidisciplinary team between January 2013 and December 2020. Availability of pathological results after resection or CT-/EBUS-guided sampling was mandatory for study inclusion. Two groups were formed: Group A (malignant nodule; n = 238) and Group B (benign nodule; n = 148). Initially, 22 potential score parameters were derived from the patients' medical histories.

RESULTS

After uni- and multivariate analysis, we identified the following eight parameters that were integrated into a scoring system: (1) age (Group A: 64.5 ± 10.2 years vs. Group B: 61.6 ± 13.8 years; multivariate p-value: 0.054); (2) nodule size (21.8 ± 7.5 mm vs. 18.3 ± 7.9 mm; p = 0.051); (3) spiculation (73.1% vs. 41.9%; p = 0.024); (4) solidity (84.9% vs. 62.8%; p = 0.004); (5) size dynamics (6.4 ± 7.7 mm/3 months vs. 0.2 ± 0.9 mm/3 months; p < 0.0001); (6) smoking history (92.0% vs. 43.9%; p < 0.0001); (7) pack years (35.1 ± 19.1 vs. 21.3 ± 18.8; p = 0.079); and (8) cancer history (34.9% vs. 24.3%; p = 0.052). Our model demonstrated superior precision to that of the Mayo score (p = 0.013) with an overall correct classification of 96.0%, a calibration (observed/expected-ratio) of 1.1, and a discrimination (ROC analysis) of AUC (95% CI) 0.94 (0.92-0.97).

CONCLUSIONS

Focusing on essential parameters, LIONS PREY can be easily and reproducibly applied based on computed tomography (CT) scans. Multidisciplinary team members could use it to facilitate decision making. Patients may find it easier to consent to surgery knowing the likelihood of pulmonary malignancy. The LIONS PREY app is available for free on Android and iOS devices.

[Mimics of lung cancer]

Lung cancer is a histologically, immunologically and therefore morphologically and functionally very heterogeneous group of neoplasms with the highest cancer mortality worldwide. Therefore, the range of diseases mimicking lung cancer is also very broad and includes congenital, infectious and inflammatory changes as well as other benign space-occupying lesions and other primary and secondary pulmonary neoplasms. The difficulty in radiology lies in the ability to diagnose lung cancer with a high degree of certainty. This must take the limits of the specific diagnosis, knowledge of the classical pitfalls and rare entities that can imitate lung cancer into consideration. Narrowing the differential diagnosis requires close interdisciplinary cooperation and consideration of the patient's clinical and medical history. An accurate analysis of the computed tomography (CT) pattern and distribution of the lesions as well as consideration of additional changes and involvement of other organ systems can be the key to the diagnosis. The use of fluorodeoxyglucose positron-emission tomography CT (FDG-PET-CT) is helpful only in a few mimics of lung cancer. The article describes clinical and radiological findings of mimics of lung cancer also pointing out the limitations of CT and PET-CT for the diagnosis.

Diagnostik granulomatöser Erkrankungen mit Lungenbefall

Granulome als Zeichen der spezifischen Entzündung im Lungengewebe treten bei vielen Erkrankungen auf. Das radiologische Standardverfahren bei pulmonalen Granulomatosen ist meistens die Dünnschichtcomputertomografie. Bei klinischem Verdacht und entsprechenden Hinweisen in der Thoraxübersicht sind eine Dünnschicht-CT und die interdisziplinäre Diskussion der Befunde zu empfehlen.

[Pulmonary granulomatous diseases and pulmonary manifestations of systemic granulomatous disease : Including tuberculosis and nontuberculous mycobacteriosis]

CLINICAL/METHODICAL ISSUE

Granulomas as signs of specific inflammation of the lungs are found in various diseases with pulmonary manifestations and represent an important imaging finding.

STANDARD RADIOLOGICAL METHODS

The standard imaging modality for the work-up of granulomatous diseases of the lungs is most often thin-slice computed tomography (CT). There are a few instances, e. g. tuberculosis, sarcoidosis and silicosis, where a chest radiograph still plays an important role.

METHODICAL INNOVATIONS

Further radiological modalities are usually not needed in the routine work-up of granulomatous diseases of the chest. In special cases magnetic resonance imaging (MRI) and positron emission tomography (PET)-CT scans play an important role, e. g. detecting cardiac sarcoidosis by cardiac MRI or choline C‑11 PET-CT in diagnosing lung carcinoma in scar tissue after tuberculosis.

PERFORMANCE

The accuracy of thin-slice CT is very high for granulomatous diseases.

ACHIEVEMENTS

In cases of chronic disease and fibrotic interstitial lung disease it is important to perform thin-slice CT in order to diagnose a specific disease pattern. Thin-slice CT is also highly sensitive in detecting disease complications and comorbidities, such as malignancies. Given these indications thin-slice CT is generally accepted in the routine daily practice.

PRACTICAL RECOMMENDATIONS

A thin-slice CT and an interdisciplinary discussion are recommended in many cases with a suspected diagnosis of pulmonary granulomatous disease due to clinical or radiographic findings.