PET Scan Best for Mesothelioma Diagnosis

A new Japanese study finds that Positron Emission Tomography (PET) scans may be the most effective way to diagnose and establish a prognosis for mesothelioma.

Mesothelioma is a very fast-growing cancer that begins in the mesothelial membranes that line the lungs, heart, and abdominal organs. It is caused by asbestos exposure, which most often occurs at a patient’s occupation. Mesothelioma is highly resistant to many traditional cancer treatments like chemotherapy and radiation, so early diagnosis of this disease is vital.

Mesothelioma may be challenging to diagnose because in many cases, mesothelioma symptoms mimic those of more common conditions such as the flu. If a patient’s history suggests mesothelioma, tumor location, shape, and size may be determined with advanced imaging technology like computed tomography (CT) and X-rays. However, CT scans have a limited ability to distinguish mesothelioma tumors from benign tumors or pleural thickening. Because of this, a growing number of doctors are depending on PET scans to help them reach a mesothelioma diagnosis.

PET scans are able to detect changes in metabolic activity that may point to cancer. When the radioactive tracer molecule 18-fluorodeoxyglucose (FDG) is injected into a patient, PET scanners can form images of the distribution of this chemical around the body. Cancer cells have a higher rate of “uptake” of FDG than other, healthy cells. The Japanese research team confirmed that patients who have malignant mesothelioma have much higher FDG uptake levels than patients who have non-malignant pleural disease.

The new study was published in Experimental and Therapeutic Medicine. Among the 47 patients studied, the patients with the highest rates of FDG uptake also had the lowest rate of survival. The study authors concluded, “Our data suggest that SUVMax levels are useful as an aid for diagnosis and prognosis of malignant pleural mesothelioma.”