Evaluating the roLe of Multiplexed PET Imaging in the Detection and Staging of hepatocellulaR Carcinoma and gAstro-entero-pancreatic Tumors

Precision medicine is a major goal in oncology. It aims to tailor treatments to the specific characteristics of each patient's tumor. This approach makes it possible to identify unique therapeutic targets and select the therapeutic alternative that specifically targets the abnormalities identified. Positron emission tomography (PET) plays a key role in this approach by providing detailed functional imaging of tumors in a non-invasive way. Usually, one radio-tracer is used to perform PET. Depending on the type of tumor, each tracer is carefully selected for its specific behavior and characteristics. However, it may be useful to perform several PET scans with different tracers, each providing different information, for the initial staging and therapeutic management of patients. Hepatocellular carcinoma (HCC), the most common form of liver cancer and the third leading cause of cancer-related death, requires precise imaging for optimal treatment selection. \[18F\]F-choline PET is often preferred for the initial detection of well-differentiated HCC and local recurrence, while \[18F\]FDG (fluorodésoxyglucose) PET is more useful for aggressive forms of HCC and for assessing metastases. Similarly, gastro-entero-pancreatic tumors (GEP-NETs), a type of neuroendocrine tumor found in the gastrointestinal tract and pancreas, also benefit from tailored imaging approaches. GEP-NETs commonly express somatostatin receptors, which are effectively targeted by \[68Ga\]Ga-DOTATOC PET to enhance diagnostic accuracy and staging, particularly in well-differentiated lesions. Conversely, \[18F\]FDG PET is valuable for imaging GEP-NETs with high metabolic activity, providing insight into tumor aggressiveness and proliferation. The combined use of \[18F\]FDG PET and \[18F\]F-choline PET in HCC, as well as \[68Ga\]Ga-DOTATOC PET and \[18F\]FDG PET in GEP-NETs, provides complementary information that helps to comprehensively characterize the tumor, guide treatment decisions, and monitor therapeutic response. In this context, a highly innovative way using multiplexed PET imaging offers potential for targeted therapy and precision medicine. The aim of this study is to evaluate the use of simultaneous dual-tracer PET imaging with a staggered injection (referred to here as multiplexed PET), combining \[18F\]FDG and \[18F\]F-choline in HCC, and \[68Ga\]Ga-DOTATOC and \[18F\]FDG in GEP-NETs as compared to both pairs of single PET.