Publication of TLRC researchers selected as “Best Clinical Article in 2019” by the Journal of Nuclear Medicine
Knowing the exact size and location of tumors is essential for a reliable cancer diagnosis and crucial for decisions on treatment options. DZL researchers from the Heidelberg site TLRC developed a new method based on positron emission tomography (PET), which allows more accurate imaging of widespread cancers. It also opens up the possibility for the development of novel cancer therapies. The Journal of Nuclear Medicine (JNM) honoured the work of the research team by electing one of its publications as the “Best Clinical Article” of the year 2019.
The new method takes advantage of the fact that a large proportion of most tumors consists of benign connective tissue. In contrast to normal connective tissue though, cancer-associated connective tissue cells (fibroblasts) contain large amounts of an enzyme called fibroblast activation protein (FAP). The researchers were able to visualise FAP, by radioactively labelling a molecule that binds to it, injecting cancer patients with this molecule and subsequently examining them using PET computer tomography (PET-CT). The radioactively labelled molecule is called 68Ga-FAP- inhibitor (68Ga-FAPI) and was used as a so-called tracer. The tracer selectively accumulates in the tumor, therefore, it clearly stands out against surrounding healthy tissue on PET-CT images. The team showed that the FAPI-tracer can help to obtain more accurate pictures of certain tumors compared to the most commonly used tracer 18F-fluorodeoxyglucose (18F-FDG). Additionally, FAPI has the potential to become a new tool for treating cancer. As FAPI primarily accumulates in cancerous tissue, aggressive radioactive molecules could be linked to it in order to destroy the tumor.
The study that was recognised by the JNM focused on testing how well the new FAPI-tracer detects different kinds of cancer. Therefore, the team of Professor Uwe Haberkorn examined cancer patients with confirmed diagnoses using the new tracer. The researchers performed dosimetric calculations and found that the radiation exposure of the method was lower compared to other imaging methods including FDG. They were able to image 28 different types of cancer and corresponding metastases using the FAPI-tracer, but these tumors showed variations in the amount of tracer uptake. However, due to the low background activity in normal tissues resulting in a high contrast image resolution was still high. The best resolution could be achieved for several widespread cancers such as breast cancer, esophageal cancer, pancreatic cancer, colon cancer and lung cancer.
The new method is not limited to the diagnosis and treatment of cancer. Also, heart diseases and fibroses of the kidney, liver and lung are characterised by tissue remodelling which is accompanied by FAPI-accumulation.
The FAPI-tracer has already been applied in German hospitals and will be evaluated in prospective clinical studies in the USA and Australia.
/ TLRC - Doreen Penso Dolfin
Research Article:
68Ga-FAPI PET/CT: Tracer Uptake in 28 Different Kinds of Cancer. Kratochwil C, Flechsig P, Lindner T, Abderrahim L, Altmann A, Mier W, Adeberg S, Rathke H, Röhrich M, Winter H, Plinkert PK, Marme F, Lang M, Kauczor HU, Jäger D, Debus J, Haberkorn U,Giesel FL. (2019) J Nucl Med. 60 (6):801-805.
Announcement by Society of Nuclear Medicine & Molecular Imaging