FDG-PET/CT may be a more effective way to track malignant pleural mesothelioma recurrence than contrast-enhanced CT scanning.
That is the conclusion of cancer researchers with Japan’s Hyogo College of Medicine.
The researchers focused on fifty patients who underwent radical surgery for pleural mesothelioma. Afterwards, doctors used both FDG-PET/CT and contrast-enhanced CT scans to track mesothelioma progression.
Two experienced examiners assessed the cases. They concluded that FDG-PET/CT was more accurate than CT for diagnosing mesothelioma recurrence.
Mesothelioma Recurrence After Surgery
Pleural mesothelioma is one of the most difficult cancers to treat. It arises in the layers of the pleural membrane that surrounds the lungs. Mesothelioma tumors tend to grow and spread quickly.
Treatments like chemotherapy, surgery, and radiotherapy can sometimes slow down mesothelioma progression. But mesothelioma recurrence is common, even with the best therapies.
To treat a recurrent tumor, doctors first have to know about it. Patients do not always have symptoms right away when a mesothelioma tumor starts to grow again.
If mesothelioma recurrence is suspected, doctors may use imaging technologies like PET scans or CT scans to confirm it.
FDG-PET/CT Versus CT Scanning
Positron Emission Tomography (PET) scanning tracks the metabolic rate of cells. Fast metabolizing cells like mesothelioma cells show up as bright spots on PET scans. Injecting a tracer called fluorodeoxyglucose (FDG) before the PET scan enhances the effect.
Computed tomography (CT) scans take a series of X-ray images from different angles. The images are combined to create a 3D picture of a mesothelioma tumor. Both types of imaging studies can show mesothelioma recurrence.
In the new Japanese study, 50 patients suspected of mesothelioma recurrence had both kinds of tests. Researchers compared the tests with each other and with pathology results. Patients were tracked for six months or more to confirm whether or not their tumors really had grown.
Diagnosing Mesothelioma Progression
Mesothelioma progressed in 40 of the patients. Fourteen patients had a change in their treatment plan based on their FDG-PET/CT results.
Additionally, FDG-PET/CT showed six cases of mesothelioma recurrence that did not show up on CT scans. In four cases, this led to a change of treatment.
Lead author Kazuhiro Kitajima concludes, “FDG-PET/CT findings were shown to be more accurate for assessing malignant pleural mesothelioma recurrence and more often led to therapy change than contrast-enhanced CT.”
Accurate assessment of mesothelioma recurrence is critical to survival. Most pleural mesothelioma patients have a life expectancy of fewer than 18 months.
Kitajima, K, et al, “Clinical utility of FDG-PET/CT for post-surgery surveillance of malignant pleural mesothelioma – Comparison with contrast-enhanced CT”, November 26, 2019, Oncotraget, pp. 6816-6828, http://www.oncotarget.com/index.php?journal=oncotarget&page=article&op=view&path=27324&path=88726