Diagnostic Accuracy of CT Limited for Pleural Mesothelioma

When it comes to diagnosing pleural mesothelioma, Scottish researchers say CT scanning is not accurate enough.

Contrast-enhanced computed tomography (CT) can provide a cross-sectional image of the chest in people with suspected pleural mesothelioma.

But researchers at Queen Elizabeth University Hospital in Glasgow say their tests show that CT is not sensitive enough to either confirm or rule out mesothelioma in most cases.

CT Scans and Mesothelioma Diagnosis

CT scanning is an imaging procedure that uses special X-ray equipment to create detailed cross-sectional images. These images are then compiled to create three-dimensional models. CT scanning is a routine part of mesothelioma diagnosis.

But the new report published in the journal Lung Cancer suggests that false positive and false negative mesothelioma diagnoses are very possible.

To make that determination, they looked at routinely acquired CT scans in malignant mesothelioma patients enrolled in a multi-center study of mesothelioma biomarkers. CTs included were performed between January 2014 and April 2016.

CT Not Accurate Enough?

After comparing the scan results to the final confirmed mesothelioma diagnosis in the cases of more than 300 patients, they determined that CT correctly identified pleural mesothelioma about 58 percent of the time. It correctly ruled out mesothelioma in about 80 percent of cases.

Not surprisingly, there were more correct mesothelioma diagnoses among those scans that were interpreted by a specialized thoracic radiologist.

“The diagnostic performance of CT in routine clinical practice is insufficient to exclude or confirm pleural mesothelioma,” writes Dr. Selina Tsim with the Pleural Disease Unit at Queen Elizabeth.

The reports suggests that a negative CT scan does not negate the need for a pleural biopsy in people with suspected pleural mesothelioma.  

The Challenge of Diagnosing Mesothelioma

As with many cancers, early and accurate mesothelioma diagnosis can significantly impact mesothelioma survival. Unfortunately, by the time many patients begin to notice symptoms such as chest pain, cough and shortness of breath, their mesothelioma may already be in an advanced stage.

Last year, a team of Japanese researchers attempted to help improve the diagnostic accuracy of CT by developing an MPM-CT Index. They found the index to be highly accurate at filtering out non-mesotheliomas with CT results alone.

In addition, larger centers have found that combining CT with positron emission tomography (PET) scanning may also improve diagnostic accuracy in mesothelioma. PET scanning uses a special dye with radioactive tracers to pinpoint areas of higher metabolic activity, which may indicate cancer.

Sources:

Tsim, S, et al, “The diagnostic performance of routinely acquired and reported computed tomography imaging in patients presenting with suspected pleural malignancy”, January 2017, pp. 38-43

Kato, K, et al, “Computed Tomographic Features of Malignant Peritoneal Mesothelioma”, March 2016, Anticancer Research, pp. 1067-72