One of the most common treatment protocols used to ease symptoms for patients diagnosed with malignant mesothelioma is a procedure known as talc pleurodesis. The treatment addresses the discomfort and breathing difficulties caused by pleural effusions, a build-up of fluid around the lungs. This buildup causes tremendous pressure and makes it nearly impossible for patients to take a deep breath, and it is successfully treated by injecting a solution of talc into the space where the fluid appears. Unfortunately, though this fixes one problem and makes patients more comfortable, it also skews the results of PET scans, one of the most accurate ways to assess whether chemotherapy and other treatments have effectively stopped tumor progression. Now researchers have found a fix for this significant challenge.
Inaccurate PET/CT results caused by talc
According to Japanese researchers, mesothelioma patients who have had talc pleurodesis can benefit from a small adjustment to the way that their PET/CT scan tests are administered. PET, or positron emission tomography, is one of the most accurate diagnostic tests for tumor growth, particularly when it is combined with CT (computed tomography). When PET/CT is administered, patients get an injection of a material called FDG (fluorodeoxyglucose) that highlights tumor cells, making them more visible to physicians. But when a patient has had talc pleurodesis, the FDG can collect in the areas where the talc has been inserted, giving those looking at the test results an inaccurate picture of the patients’ condition.
Scientists recommend use of different tracer in PET/CT following talc pleurodesis
In response to this finding, the researchers tested a different methodology on mesothelioma patients who had undergone talc pleurodesis, and they found it delivered much more accurate results. Rather than injecting the patients with FDG before the scan, the researchers used a material called Choline C-11 which does not get absorbed by the inserted talc. Instead, the choline C-11 only gets absorbed by true cancer cells, thus giving physicians a much better sense of the impact of the treatments they have administered. As a result, the researchers are suggesting that imaging studies conducted on patients who have already had talc pleurodesis adopt the use of Choline C-11 as a tracer.
Making necessary adjustments is the new normal for those diagnosed with malignant mesothelioma. For information on other options to make your life easier, contact the Patient Advocates at Mesothelioma.net at 1-800-692-8608.