For patients with pancreatic ductal adenocarcinoma, molecular imaging may improve staging and clinical management of the disease, according to research published by Röhrich et al in The Journal of Nuclear Medicine. In a retrospective study of patients with pancreatic ductal adenocarcinomas, the addition of positron-emission tomography/computed tomography (PET/CT) imaging with gallium-68–labeled FAP inhibitors (Ga-68-FAPI) led to restaging of disease in more than half of the patients, most notably in those with local recurrence.
FAP is a new target molecule for PET imaging of various tumors. Optimal imaging of pancreatic ductal adenocarcinoma is crucial for accurate initial TNM staging and selection of primary treatment. Follow-up imaging is also important to accurately detect local recurrence or metastatic spread as early and as completely as possible.
“Currently, contrast-enhanced CT is the gold standard when it comes to TNM staging, and PET imaging isn’t typically part of the clinical routine,” stated Manuel Röhrich, MD, a nuclear medicine physician at Heidelberg University Hospital in Heidelberg, Germany. “However, we know that pancreatic ductal adenocarcinoma is composed of certain fibroblasts that express fibroblast activation protein, which can be imaged with the novel PET radiotracer Ga-68-FAPI. Given this characteristic, we sought to explore the utility of Ga-68-FAPI PET/CT to image patients with [this pancreatic cancer].”
Effect of Imaging
The study included 19 patients who received contrast-enhanced CT imaging followed by Ga-68-FAPI PET/CT. Results from the Ga-68-FAPI PET/CT scans were then compared with TNM staging based on contrast-enhanced CT. Changes in oncological management were recorded.
Ga-68-FAPI PET/CT-based TNM staging differed from contrast-enhanced CT imaging in 10 out of 19 patients, which resulted in changes in TNM staging. Of the 12 patients with recurrent disease, 8 were upstaged, 1 was downstaged, and 3 remained the same. In the seven patients newly diagnosed with pancreatic ductal adenocarcinoma, one was upstaged, while the staging remained the same for six of the patients.
“This analysis suggests that Ga-68-FAPI PET/CT is a promising new imaging modality in staging of pancreatic ductal adenocarcinoma that may help to detect new or clarify inconclusive results obtained by standard CT imaging,” said Dr. Röhrich.
He added, “Improvement in survival can only be achieved by effective treatment approaches customized to the individual patient’s disease status. Thus, hybrid imaging using FAPI tracer may open up new applications in staging and restaging of pancreatic ductal adenocarcinoma.”
Disclosure: For full disclosures of the study authors, visit jnm.snmjournals.org.
