Pulmonary fibrosis – novel imaging technique to visualize active scarring processes
TLRC researchers are developing imaging techniques to improve visualization of pulmonary fibrosis. In a study published in the Journal of Nuclear Medicine, they showed that computed tomography combined with positron emission tomography (PET/CT) can be used to image cells actively involved in the scarring process of the lung. Further studies will be conducted to determine whether the new technique can provide a more accurate prognosis and be used to test new therapies.
Pulmonary fibrosis, or "scarred lung", is a collective term for various clinical pictures in which remodelling of the lung skeleton continuously reduces the functional capacity of the lung. During the course of fibrosis, excess connective tissue is formed. When it hardens and scars, the lung's expandability and its ability to exchange gases are severely restricted. The lung function of those affected is reduced. Initially, they suffer from shortness of breath and an irritating cough. As the disease progresses quickly, it often leads to premature death.
Computed tomography is already used as a standard imaging technique to diagnose pulmonary fibrosis, but it cannot image the activity of the fibrosing processes. A team of researchers from Heidelberg University Hospital, the Thoraxklinik Heidelberg and the German Cancer Research Center has therefore investigated whether CT in combination with PET is suitable for obtaining this information. They investigated whether they can make active scarring processes visible by visualising the activity of certain connective tissue cells - the fibroblasts. Active fibroblasts produce large amounts of fibroblast activation protein (FAP). The researchers used radiolabelled molecules called FAPI tracers to visualize FAP on PET/CT images of the lung.
For the pilot study, PET/CT images of lungs of 15 patients with an average age of 71 years were retrospectively analysed. FAPI-PET/CT was found to be well suited for imaging fibrosing and inflammatory tissue processes. The advantage of the method is that it can be used to visualize active scarring processes that indicate rapid progression of the disease. Further clinical studies with a larger number of subjects are planned to confirm the validity of this method for clinical application. If the method proves successful, it might be used to test whether scarring processes can be slowed down or even stopped by taking medication. It might also be used to improve prognosis on the disease course.
/ TLRC - Doreen Penso Dolfin
Further information:
Fibroblast Activation Protein specific PET/CT imaging in fibrotic interstitial lung diseases and lung cancer: a translational exploratory study. Röhrich M, Leitz D, Glatting FM, Wefers AK, Weinheimer O, Flechsig P, Kahn N, Mall MA, Giesel FL, Kratochwil C, Huber PE, von Deimling A, Heußel CP, Kauczor HU, Kreuter M, Haberkorn UA.J Nucl Med. 2021 Jul 16:jnumed.121.261925. doi: 10.2967/jnumed.121.261925.