New data highlights the prognostic value of PET/CT scans for patients with malignant pleural mesothelioma.
Pleural mesothelioma is a rare malignancy with a poor prognosis. But some patients tend to do better than others. Scientists are always looking for better ways to predict which patients will respond best to which treatment.
A new Turkish study focused on the prognostic value of scans that measure tumor volume and metabolic activity. They conclude that PET/CT is a valuable way to predict mesothelioma outcomes. Doctors can use the information to help plan for chemotherapy or surgical treatment.
How PET/CT Scans Work
Doctors have been aware of malignant mesothelioma since the 1930s. That is when it first started appearing among asbestos workers. But there are still many things about mesothelioma that are unknown.
One mystery is why some asbestos-exposed people get this rare cancer while others do not. Another mystery is why a treatment that works well in one patient does not work as well in another.
That is why it is important for doctors to know the prognostic value of PET/CT. PET stands for positron emission tomography. It is usually used along with a radioactive tracer (called FDG) to measure the metabolic rate of tumors. The amount of tracer absorbed by a tumor is the maximum standardized uptake volume (SUV).
CT stands for computed tomography. A CT scan takes multiple X-ray images from different angles. Together, the X-ray images create a 3D picture of internal structures. Doctors can use CT data to measure the volume of a mesothelioma tumor.
Determining the Prognostic Value of PET/CT
Doctors often use a combined PET/CT to diagnose mesothelioma. But the Turkish researchers say the method has high prognostic value, too. Prognosis is more than a way to predict whether a patient will live or die. It is also an important tool for choosing the right mesothelioma treatment.
The new study included 65 pleural mesothelioma patients. The youngest patient was 39 and the oldest was 84. The group included 34 men and 31 women. The patients had PET/CT (with FDG) for staging between 2008 and 2018.
Researchers compared the scan results with each patient’s outcome to determine the prognostic value of PET/CT. The average survival time was 17 months. About 35 percent of patients were still alive two years after treatment. Just under 8 percent lived for five years.
Factors Linked to Mesothelioma Survival
Being older than 60 and having mesothelioma on the left side of the chest were both linked to shorter survival. But the PET/CT scans also proved to have significant prognostic value. People with an SUV of more than 9.8 had shorter survival than those with lower values.
Those with a total lesion glycolysis (TLG) of more than 180.2 g also lived for a shorter time. Doctors find this number by multiplying the average SUV (PET data) by the tumor volume (CT data).
“Metabolic parameters of [FDG PET/CT] have the potential to provide prognostic information for malignant pleural mesothelioma patients who are receiving surgery and/or chemotherapy,” writes author Bülent Mustafa Yenigün. A Turkish medical journal published the article.
The prognostic value of PET/CT is one reason that mesothelioma patients should look for an experienced medical center. Larger medical centers tend to have more advanced diagnostic equipment and more experienced doctors. Multiple studies suggest that patients who get mesothelioma treatment at larger cancer centers have the best outcomes.
Yenigün, BM, et al, “The prognostic value of 18F-fluorodeoxyglucose positron emission tomography/ computed tomography parameters in patients with malignant pleural mesothelioma”, January 13, 2021, Turkish Journal of Thoracic and Cardiovascular Surgery, January 13, 2021, Online ahead of print, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7970077/