Thoracic computed tomography findings in malignant mesothelioma

Differentiating malignant pleural mesothelioma and metastatic pleural disease based on a machine learning model with primary CT signs: A multicentre study

Rationale and Objectives

It is still a challenge to make confirming diagnosis of malignant pleural mesothelioma (MPM), especially differentiating from metastatic pleural disease (MPD). The aim of this study was to develop a model to distinguish MPM with MPD based on primary CT signs.

Materials and methods

We retrospectively recruited 150 MPM patients and 147 MPD patients from two centers and assigned them to training (115 MPM patients and 113 MPD patients) and testing (35 MPM patients and 34 MPD patients) cohorts. The images were analyzed for pleural thickening, hydrothorax, lymphadenopathy, thoracic volume and calcified pleural plaque (CPP). The selected clinical characteristics and primary CT signs comprised the model by multivariate logistic regression in the training cohort. Then the model was tested on the external testing cohort. ROC curve and F1 score were used to validate the capability of the model in both two cohorts.

Results

There were significant differences between two groups: (1) carcinoembryonic antigen (CEA); (2) nodular and mass pleural thickening; (3) the enhancement of pleura; (4) focal, diffuse and circumferential pleural thickening; (5) the thickest pleura; (6) thickening of diaphragmatic pleura; (7) multiple nodules and effusion of interlobar pleura; (8) hilar LN and ring enhancement of LN; (9) punctate and stipe CPP. The AUC and F1 score of the model were 0.970 and 0.857 in the training cohort, 0.955 and 0.818 in the testing cohort.

Conclusion

The model holds promise for use as a diagnostic tool to distinguish MPM from MPD.

Integrating data from multidisciplinary Management of Malignant Pleural Mesothelioma: a cohort study

BACKGROUND

Malignant pleural mesothelioma (MPM) is a rare and aggressive malignancy that most commonly affects the pleural layers. MPM has a strong association with asbestos, mainly caused by exposure to its biopersistent fibers in at least 80% of cases. Individuals with a chronic exposure to asbestos might develop disease with a 20-40-year latency with few or no symptoms. Such has been the case in the Italian regions of Piedmont and Lombardy, where industrial production of materials laden with asbestos, mainly cements, has been responsible for the onset of a large epidemic. Since 2018, a multidisciplinary team at San Matteo hospital in Pavia has been collecting data on over 100 patients with MPM. The main goal of this project is to define and describe an integrated profile for each MPM case at diagnosis by using data mining and partition analysis.

METHODS

Here we bring together exhaustive epidemiologic, histologic and radiologic data of 88 MPM patients that came to our observation and draw correlations with predictive and prognostic significance.

RESULTS

The median overall survival (OS) was 15.6 months. Most patients presented with pleural effusion, irrespective of disease stage. Quite unexpectedly, no statistically significant association was demonstrated between OS and TNM disease stage at diagnosis. Although average OS is similar in male and female patients, partition analysis of data underlined a significant differential hierarchy of predictor categories based on patient gender. In females with no smoking history, full chemotherapeutic regimens are associated with better outcomes. Moreover, concerning second line treatments, vinorelbine emerged as the most advantageous choice for female patients, whereas in the male subgroup no statistically significant difference resulted between gemcitabine and vinorelbine.

CONCLUSION

A multidisciplinary approach to MPM is mandatory to define better therapeutic approaches, personalize the management and improve patient outcomes.

Malignant Pleural Mesothelioma: Genetic and Microenviromental Heterogeneity as an Unexpected Reading Frame and Therapeutic Challenge

Mesothelioma is a malignancy of serosal membranes including the peritoneum, pleura, pericardium and the tunica vaginalis of the testes. Malignant mesothelioma (MM) is a rare disease with a global incidence in countries like Italy of about 1.15 per 100,000 inhabitants. Malignant Pleural Mesothelioma (MPM) is the most common form of mesothelioma, accounting for approximately 80% of disease. Although rare in the global population, mesothelioma is linked to industrial pollutants and mineral fiber exposure, with approximately 80% of cases linked to asbestos. Due to the persistent asbestos exposure in many countries, a worldwide progressive increase in MPM incidence is expected for the current and coming years. The tumor grows in a loco-regional pattern, spreading from the parietal to the visceral pleura and invading the surrounding structures that induce the clinical picture of pleural effusion, pain and dyspnea. Distant spreading and metastasis are rarely observed, and most patients die from the burden of the primary tumor. Currently, there are no effective treatments for MPM, and the prognosis is invariably poor. Some studies average the prognosis to be roughly one-year after diagnosis. The uniquely poor mutational landscape which characterizes MPM appears to derive from a selective pressure operated by the environment; thus, inflammation and immune response emerge as key players in driving MPM progression and represent promising therapeutic targets. Here we recapitulate current knowledge on MPM with focus on the emerging network between genetic asset and inflammatory microenvironment which characterize the disease as amenable target for novel therapeutic approaches.

Diagnostic Imaging and workup of Malignant Pleural Mesothelioma

Malignant pleural mesothelioma is the most frequent primary neoplasm of the pleura and its incidence is still increasing.This tumor has a strong association with exposure to occupational or environmental asbestos, often after a long latent period of 30-40 years.Plain chest radiography (CXR) is usually the first-line radiologic examination, but the radiographic findings are nonspecific due to its limited contrast resolution and they need to be complemented by other imaging modalities such as computed tomography (CT), magnetic resonance Imaging (MRI), Positron emission tomography-computed tomography (PET-CT) and ultrasound (US).The aim of this paper is to describe the imaging  features of this malignancy, underlining the peculiarity of CXR, CT, MRI, PET-CT and US and also focusing on diagnostic workup, based on the literature evidence and according to our experience.

Effects of gadolinium-based contrast agent concentrations (0.5 M or 1.0 M) on the diagnostic performance of magnetic resonance imaging examinations: systematic review of the literature

Background To date there is no agreement as to what is the optimal concentration for gadolinium-based contrast agents (GBCAs). Purpose To assess whether diagnostic performance differences exist between 0.5 M and 1.0 M GBCAs used for magnetic resonance imaging (MRI). Material and Methods A PubMed literature search identified 21 clinical studies published between 2005 and 2013 which evaluated the diagnostic efficacy of both types of GBCAs. Study design, type of procedure, GBCA administration mode, imaging performances, impact on patient management, study limitations, and biases were analyzed. No statistical test was performed on pooled data. Results Sixteen comparative and five non-comparative studies were analyzed, involving 2183 patients who underwent MRI procedures for various indications. In 67% of the studies, 0.5 M and 1.0 M GBCAs were injected at equimolar gadolinium amounts per kg body weight. Only 33% applied the same molar flow rate for delivery of the GBCAs. No significant differences between GBCAs were reported for 23 out of 27 qualitative endpoints (mainly image quality, lesion, and vessel visualization) and 29 out of 40 quantitative endpoints. Three out of four studies with non-equimolar delivery rates showed better contrast-to-noise and signal-to-noise ratios for 1.0 M gadobutrol, without showing an impact on diagnostic performance. Methodological biases were identified in several studies impairing the interpretation of comparisons. Conclusion Imaging differences between 0.5 M and 1.0 M GBCAs were essentially observed under non-equimolar delivery rates. However, they did not result into greater diagnostic efficacy when performed under equimolar conditions.

Recurrent hydropneumothorax: An unusual presentation for malignant pleural mesothelioma

Mesothelioma is a rare pulmonary malignancy commonly associated with asbestos exposure. Its presentation is insidious and non-specific, with complaints of chest pain, dyspnea and cough. Chest X-ray may demonstrate unilateral pleural effusion. CT and PET scans may highlight nodular pleural plaques. Diagnosis often times is difficult with negative imaging and negative pleural fluid studies. In rare cases, hydropneumothoraces may be seen. We report a case of malignant pleural mesothelioma presenting as recurrent hydropneumothorax with negative CT scan of the chest for pleural abnormalities and negative pleural fluid studies.

Multidetector CT Findings and Differential Diagnoses of Malignant Pleural Mesothelioma and Metastatic Pleural Diseases in Korea

Objective

To compare the multidetector CT (MDCT) features of malignant pleural mesothelioma (MPM) and metastatic pleural disease (MPD).

Materials and Methods

The authors reviewed the MDCT images of 167 patients, 103 patients with MPM and 64 patients with MPD. All 167 cases were pathologically confirmed by sonography-guided needle biopsy of pleura, thoracoscopic pleural biopsy, or open thoracotomy. CT features were evaluated with respect to pleural effusion, pleural thickening, invasion of other organs, lung abnormality, lymphadenopathy, mediastinal shifting, thoracic volume decrease, asbestosis, and the presence of pleural plaque.

Results

Pleural thickening was the most common CT finding in MPM (96.1%) and MPD (93.8%). Circumferential pleural thickening (31.1% vs. 10.9%, odds ratio [OR] 3.670), thickening of fissural pleura (83.5% vs. 67.2%, OR 2.471), thickening of diaphragmatic pleura (90.3% vs. 73.4%, OR 3.364), pleural mass (38.8% vs. 23.4%, OR 2.074), pericardial involvement (56.3% vs. 20.3%, OR 5.056), and pleural plaque (66.0% vs. 21.9%, OR 6.939) were more frequently seen in MPM than in MPD. On the other hand, nodular pleural thickening (59.2% vs. 76.6%, OR 0.445), hilar lymph node metastasis (5.8% vs. 20.3%, OR 0.243), mediastinal lymph node metastasis (10.7% vs. 37.5%, OR 0.199), and hematogenous lung metastasis (9.7% vs. 29.2%, OR 0.261) were less frequent in MPM than in MPD. When we analyzed MPD from extrathoracic malignancy (EMPD) separately and compared them to MPM, circumferential pleural thickening, thickening of interlobar fissure, pericardial involvement and presence of pleural plaque were significant findings indicating MPM than EMPD. MPM had significantly lower occurrence of hematogenous lung metastasis, as compared with EMPD.

Conclusion

Awareness of frequent and infrequent CT findings could aid in distinguishing MPM from MPD.

Pleural irregularities and mediastinal pleural involvement in early stages of malignant pleural mesothelioma and benign asbestos pleural effusion

OBJECTIVE

To elucidate differences in the level and localization of pleural irregularities in early malignant pleural mesothelioma (eMPM) and benign asbestos pleural effusion (BAPE) using CT.

STUDY DESIGN

Retrospective assessment of CT findings of consecutive patients with BAPE at a single centre and patients with eMPM reported in Japanese vital statistics.

METHODOLOGY

Thirty-six patients with confirmed diagnoses of BAPE and sixty-six patients with confirmed diagnoses of eMPM (mesothelioma stages T1 or T2) were included. Informed consent, CT scans, and clinical and pathologic details were obtained for all patients and were reviewed by one radiologist, two pathologists, and two pulmonologists. Asbestosis, pleural plaque, rounded atelectasis, and diffuse pleural thickening were assessed in all patients.

RESULTS

Prevalence of asbestosis, pleural plaque, rounded atelectasis, and diffuse pleural thickening was significantly higher in the BAPE group. Low-level irregularity was more common in the BAPE group (p<0.001), whereas high-level irregularity, mediastinal localization, and interlobar fissure were more prevalent in the eMPM group (p<0.001). Interlobar pleural irregularity was not observed in any patients in the BAPE group, although 55% of patients in the eMPM group showed interlobar pleural irregularity. Mediastinal pleural involvement was observed in 74% of patients in the eMPM group and had a positive predictive value of 89%.

CONCLUSION

This study demonstrates that the level and localization of plural irregularities significantly differed between patients with BAPE and eMPM. Large-scale prospective studies are needed to fully establish the diagnostic utility of such differences.

Massive localized malignant pleural mesothelioma (LMPM): manifestations on computed tomography in 6 cases

OBJECTIVE

Our study analyzed the clinical symptoms and computed tomography (CT) manifestations of massive localized malignant pleural mesothelioma (LMPM) patients to improve the knowledge and diagnosis of this disease.

METHODS

Our study collected 6 massive LMPM patients pathologically confirmed by CT in the department of Radiology of the People's Hospital of Yuyao, Zhejiang Province, from January, 2007 to June, 2013; data of patients were also collected. The clinical symptoms, clinicopathological characteristics, CT manifestations, treatments and prognosis of enrolled patients were analyzed.

RESULTS

Our study enrolled 6 LMPM patients (2 males; 4 females) classified to epitheliated type (n = 4) and sarcomatous type (n = 2) with mean age of 62.7 ± 7.4, and 5 of them had a history of asbestos exposure. CT manifestations revealed that large soft-tissue mass close to pleura, which was smooth and lobulated, was discovered in all patients with maximum diameter of 10~15 cm and mean diameter of 13.67 ± 1.15 cm; The mean value of CT was 36.29 ± 2.62 HU; after enhancement, the mean value was increased to 76.36 ± 7.73 HU; patients showed zones of small patchy necrosis and large patchy necrosis. The following presentations were founded: enlargement of tumor vessel which showed arborization (2 patients), mass wrap around the descending aorta in left lower chest (1 patient), strips of fat density in mediastinum superior (1 patient), pleural tail sign (3 patients). Among 6 patients, pleural effusion (n = 4), mediastinal lymph node enlargement (n = 3), invasion and destruction of local ribs (n = 2). Median survival time of patients were 20 months (2 cases conducted operation), 24 (2 cases chose combined radiotherapy and chemotherapy) and less than 6 months (2 cases underwent chemotherapy).

CONCLUSION

To sum up, CT showed important diagnostic values on massive LMPM patients; patients with a history of asbestos exposure, large soft-tissue mass of pleura with an abundant blood supply and wrap around large vessels might increase the risk of massive LMPM.

Bronchial artery embolization in life-threatening massive hemoptysis

Background

Massive hemoptysis is a potentially life threatening respiratory emergency and mandates immediate investigation and intervention. There is no universal consensus regarding the optimal management of these patients, and there are no large series of patients studied.

Objectives

Here we reported thirty Iranian patients who were managed with bronchial artery embolization.

Patients and Methods

All the patients had already been assessed by computerized tomography (CT) to localize and delineate the underlying etiology except 2 patients who had not undergone CT scan.

Results

Tuberculosis, bronchiectasis, and lung cancer/metastasis were the most common causes, detected in 14(47%), 5(17%) and 4(13%) patients respectively. Other causes of hemoptysis including chronic bronchitis, interlobar artery aneurysm, hydatid cyst, arteriovenous fistula, pulmonary embolism, and exposure to chemical weapons each detected in one patient separately. All of them had abnormal chest CT scans, except for 2 patients who had not undergone CT scan (one with hydatid cyst and another with bronchial tumor diagnosed with bronchoscopy). Bleeding location which has been confirmed with angiography could be predicted with CT scan among 7 of 14 patients with TB, (sensitivity=50%). While this rate was 100% among all other patients with other diagnosis who had undergone CT scan.

Conclusions

In conclusion complementary to the previous studies our results have demonstrated that bronchial artery embolization remains as one of the most efficient procedures in managing massive hemoptysis, with minimal rate of complications.